Revision of the European species of Omphale Haliday (Hymenoptera, Chalcidoidea, Eulophidae)

Abstract The European species of Omphale Haliday (Eulophidae: Entedoninae) are revised. The revision includes 37 species, of which eleven are newly described and the remaining 26 species are redescribed. The species are classified into six species groups, with six unplaced species. All species are fully diagnosed and thoroughly illustrated. Identification keys are provided for females and males. Two new morphological features to aid classification and identification are introduced: male genitalia and wing interference patterns (WIPs). The former has been used successfully in the classification of New World Omphale and the latter is used for the first time in a taxonomic revision. Male genitalia in Omphale have considerable interspecific variation, an unusual trait among chalcidoid Hymenoptera, and are demonstrated to be useful for classification of species and species-groups, and they also possess the only autapomorphy for Omphale. WIPs are useful to help separate some species, but cannot be used to define either the genus or species groups. Distributional data are compiled for each species and suggest a pan-european distribution for most species. Gall-midges are the known hosts for 14 species, and the absence of host overlap between species suggests that host specialization is a driving force for speciation. Several Omphale species are known only from females, or have a strong female biased sex ratio, suggesting thelytokous development. Apart from the 37 species included in this revision, the status for nine additional species (names) in species group aetius remain unsolved. For nomenclatorial stability, a neotype is designated for Eulophus lugens Nees (= Omphale lugens (Nees)). Elachestus obscurus Förster and Derostenus sulciscuta Thomson are transferred from Holcopelte to Omphale comb. n. Derostenus radialis Thomson and Achrysocharella americana Girault are synonymized with Omphale theana (Walker), and Omphale teresis Askew is synonymized with Omphale phruron (Walker), syn. n. The status of genus Pholema Graham is revised as it is removed from synonymy with Omphale and instead synonymized with Neochrysocharis Kurdjumov, syn. n., and the type species for Pholema, Pholema microstoma Graham, is transferred to Neochrysocharis, comb. n. Eugerium orbatum Szelényi, previously transferred to Omphale, is synonymized with Asecodes congruens (Nees), syn. n.


introduction
The genus Omphale Haliday is one of the largest genera of Entedoninae (Chalcidoidea: Eulophidae), with 259 species (Noyes 2012). It is a cosmopolitan group with uneven levels of knowledge from different parts of the World. The most recent taxonomic studies on this group are from the Americas (Hansson 1996b(Hansson , 1997(Hansson , 2004. Other parts of the World, except Europe, are very poorly known. Though originally described from Europe, the Omphale fauna from Europe has never been subject to a comprehensive taxonomic revision. Graham was the first (1959,1963) to study European Omphale from an extensive taxonomic/nomenclatural aspect, but his focus was on northern Europe and mainly on the United Kingdom. Graham (1963) included 25 species, of which six were newly described. Subsequently six new species have been described (Graham 1970, Gijswijt 1976, Szelényi 1978, Askew 2003, bringing the total to 31 European Omphale species.
The keys, species descriptions and classification in Graham are exclusively based on externomorphological characters. As Omphale species are very plain and possess relatively few such characters, of which several show a high intraspecific variation, the species are difficult to distinguish. This sparsity of characters makes Omphale one of the more difficult genera of Entedoninae to classify at the species level, and it was consequently one of the few genera in Europe that had not been studied comprehensively. The poor knowledge of this genus in Europe is further demonstrated by the fact that eleven new species are described in this paper. The new species are mainly from Sweden and the United Kingdom, two of the most well investigated countries in the World as far as the fauna of Hymenoptera and Omphale is concerned.
The relatively few available externomorphological characters have been an impediment for the classification of this group. However, later taxonomic studies from the New World Omphale (Hansson 1996b(Hansson , 1997(Hansson , 2004 have included new characters from male genitalia, which have not been applied to the European species. As opposed to the majority of Eulophidae genera where the phallobase and aedeagus -the two parts of male genitalia -show little interspecific variation, species of Omphale frequently display species-specific as well as species-group specific features in these structures. As well, wing interference patterns (WIPs), a new character present in minute winged insects discovered by , have been useful in the classification of some eulophid groups but were never investigated in Omphale. These new characters enhance the possibilities of determining species identities and relationships of European Omphale.

Male genitalia
Male genitalia in many insect groups tend to evolve divergent forms relatively rapidly compared to other structures, and can display a formidable morphological diversity (Eberhard 2009). Male genitalia are therefore frequently the richest source of morphological characters in insects (e.g. Grimaldi and Engel 2005), with important characters on different taxonomic levels. Examples of this are commonly found in e.g. Diptera (Grimaldi and Nguyen 1999), Coleoptera (Hubweber and Schmitt 2010), and Lepidoptera (Sohn and Nishida 2011). However, in the Hymenoptera, male genitalia usually show little variation at both the species and genus level (Michener 1956). There are some exceptions to this among some of the smallest species of the Chalcidoidea, in the Aphelinidae (Viggiani and Battaglia 1984) and Trichogrammatidae Nagaraja 1968, 1971;Viggiani 1971, Owen et al. 2007, where characters in male genitalia are used for the separation of species. Male genitalia in most Eulophidae conforms to the situation in most Chalcidoidea, having little variation and thus little information value (e.g. Graham 1987) -with some notable exceptions. The most striking exception is genus Perditorulus Hansson, a recently described group confined to the Americas with its main distribution in tropical America, and currently comprising close to a hundred described species. The original description of the genus (Hansson 1996a) included 33 species, all with species-specific genitalia, and with a remarkable morphological diversity of structure, unparalleled within the Chalcidoidea. A subsequent contribution to Perditorulus (Hansson 2004) has firmly established and expanded these initial findings. Another group with variation in male genitalia, and therefore with useful information for the classification, is Omphale (Hansson 1996b(Hansson , 1997(Hansson , 2004, which was one of the incentives for this study of the European species. Male genitalia in Chalcidoidea are relatively simple, consisting of the phallobase and aedeagus (Snodgrass 1941) (Fig. 478). The phallobase is the most complicated structure, forming a semiopen tube made up from three parts, the basal ring and a pair each of parameral and volsellar plates. In Eulophidae, the basal ring is not visible, and the parameral and volsellar plates are completely fused. The parameres are continuations of the parameral plates. The volsellar plates are strengthened by a ridge, the volsellar ridge, that extends along the entire length of the plates, and at the apex of this ridge there is a lobe -the digitus (digitus volsellaris) -with (digital) spines at the apex. Inside the tubular phallobase lies the aedeagus, consisting of a larger apical part -the penis valves, and two long aedeagal apodemes.
Most genera belonging to the Entedoninae have a phallobase and an aedeagus as in Fig. 478, i.e. a phallobase with weak volsellar setae (vs), two digital spines (ds), and an aedeagus with very few structures. There is little variation in this "groundplan" within the subfamily, and species of same genus and even species from different genera are more or less indistinguishable in this structure. However, male genitalia in European Omphale exhibit considerable variation in both the phallobase and the aedeagus (Figs 479-501). Male genitalia are thus an extremely useful structure for the classification and species discrimination in this group which is so deprived of other morphological characters.

Wing interference patterns (WIPs)
Wing interference patterns (WIPs) occur in transparent wings with a very thin membrane as is usually found in small insects . WIPs appear when the wings are viewed against a dark background and visualize uneven thickness of the wing membrane. These patterns have been used to define a newly described genus from the Neotropical region (Hansson 2011). Shevtsova anf Hansson (2011) demonstrated the usefulness of WIPs to separate species in the genus Achrysocharoides Girault, where some species also displayed sexual dimorphism in these patterns. Consequently WIPs can be useful for the classification at both genus and species levels. For the first time, WIPs are included herein in a large revision.
Species of Omphale do not have sexually dimorphic WIPs and all WIPs illustrated here are from females. Omphale species do not display the elaborate WIPs found in some species of Achrysocharoides, many of which have distinct eye-catching spots in the forewing , and there is no common pattern for the genus or species-groups. Nevertheless these patterns can hold important clues for the separation of species. For example, in the salicis-group, both O. cornula and O. theana have the forewing predominantly in one colour (Figs 99,129), which separates them from the other species in the group which have multicoloured WIPs (Figs 77,84,114). Omphale theana and O. cornula can be separated quite easily from each other through their WIPs even though they are basically in one colour. In O. cornula the area just below the marginal vein is differently coloured (Fig. 99), while O. theana has the same colour over the entire wing surface (Fig. 129). Similarly, in the admirabilis-group O. telephe has a one-colour WIP with an easily recognizable narrow, curved and differently coloured band just below the marginal vein (Fig. 49), while the other species have multicoloured WIPs. The multicoloured WIPs in this group also have diagnostic features, as O. admirabilis and O. breviventris have wide diagonal bands across the forewing (Figs 21,34), whereas O. versicolor has apical ½ of forewing in one colour and basal ½ with wide colour bands running more or less straight from marginal vein to the hind margin of the wing (Fig. 64). Both species in the clypealis-group also have multicoloured WIPs, but the pattern is much more distinct in O. clypealis (Fig. 327) compared to O. parma (Fig. 342). Alternately, in the aetius-group (Figs 269,284,297,312) and in most species in phruron-group (Figs 145,189,219,234,247,254), WIPs are less distinct for the species and more difficult to use for their separation. not fit in any of the species groups, and that do not share features with each other to form species groups on their own.
Biology. Hosts or host plant/fungi associations are known for 16 of the 37 European species (Table 1), and in all cases gall midges (Diptera: Cecidomyiidae) are the target group. Host records from North America (Hansson 1996b) and Central America (Hansson 2004) support the findings for European species, i.e. that Omphale species are exclusively parasitoids on gall midges. Dziurzynski (1961) investigated the biology of O. lugens in Poland (given as Secodes coactus in the Dziurzynski publication). Omphale lugens is a koinobiont primary endoparasitoid and the female oviposits in the second instar larvae of its gall midge host, Mikiola fagi, which induces galls on the upper surface of leaves of beech (Fagus sylvatica). This parasitoid is solitary or gregarious with up to ten individuals per host. If more than one larva is present per host either the same female lays more than one egg per host, or more than one female oviposits in the same host larva. However, because of the high mortality among gregarious larvae eventually only one parasitoid per host larva will complete its development. The parasitoid speeds up the development of its host, indicated by a faster growth rate in parasitized gall midge larvae, as compared to non-parasitized larvae. There does not seem to be additional, abnormal, instars in the host, just an acceleration of growth. The gall midge larva is killed before pupation by the feeding of the last instar parasitoid larva. Omphale lugens has four larval instars and pupates inside the empty larval skin of its host, still remaining inside the gall.
The only other Omphale species for which more detailed biological information is available is O. clypealis. This species is an important biological control agent against the brassica pod midge (Dasineura brassicae) on rape (Brassica napus), and has thus been the subject of biological investigation (Williams 2003). Similar to O. lugens, O. clypealis is a koinobiont endoparasitoid. Females oviposit into mature gall midge larvae in their pod gall, and the parasitoid larva is inside the host when it leaves the gall and burrows into the ground for pupation. The pupa is subsequently killed by the parasitoid. The sex ratio for O. clypealis is strongly female biased, and Murchie (1996) reared 97-100% females from samples of the brassica pod midge in the U.K. Material from this species that has been available for this investigation, 147 females and three males, suggests the same female bias. This skewed sex ratio indicates that O. clypealis is thelytokous, as are possibly some other Omphale species, such as O. rubigus where males have never been found, and O. theana in which very few males are recorded.
If data from these two species are transferrable, Omphale species are koinobiont endoparasitoids, possibly solitary -at least with only one surviving parasitoid per host. Little is known about the host specificity of Omphale species. However, known host records suggest host specialization because there are no overlap between the species. The host record for O. phruron, Dasineura pyri -same host as in O. clymene, is possibly based on a misidentification of the parasitoid. The specimens of O. phruron from D. pyri have not been available for this investigation and as the species in this group are difficult to identify misidentification cannot be ruled out.
Distribution. Even though several parts of the World are very poorly investigated or not investigated at all, existing records show that Omphale is a cosmopolitan genus,

O. salicis
Contarinia lentis (Diptera: Cecidomyiidae) (probable record) (Szelényi 1944), Contarinia loti (Gijswijt 1976 Forewing with admarginal setae arising from ventral surface of marginal vein (occasionally with a few of the apical setae arising from wing membrane just behind marginal vein) (Fig. 10), and with radial cell usually bare (Fig. 11), part between lower margin of eye and mouth opening usually with more or less strong sculpture (strigose-reticulate) (Fig. 5) (Fig. 9), and with radial cell usually setose (Fig. 12), also with part between lower margin of eye and mouth opening usually smooth or with very weak sculpture (Fig. 6) .........39 10(9) Forewing with stigmal vein enlarged and with membrane around stigmal vein infuscate (Fig. 471); completely yellow non-metallic species (Fig. 468)  Vertex yellowish brown (Fig. 474); mesoscutum with anterior ½ golden green with a median yellowish brown stripe, posterior ½ yellowish brown (Fig. 475), midlobe with two pairs of setae (Fig. 398)  Coxae dark brown to black (Fig. 402), hind coxa with apical part usually paler; petiole quadrangular with anterior part drawn out to a sharp edge that covers the propodeal nucha (as in Fig. 409 Forewing with admarginal setae arising from ventral surface of marginal vein (occasionally with a few of the apical setae arising from wing membrane just behind marginal vein) (Fig. 10), and with radial cell usually bare (Fig. 11), also part between lower margin of eye and mouth opening usually with more or less strong sculpture (Fig. 5)  Forewing with admarginal setae predominantly arising from ventral surface of wing membrane just behind marginal vein (Fig. 9), and with radial cell usually setose (Fig. 12), also with part between lower margin of eye and mouth opening usually smooth or with very weak sculpture (Fig. 6)  Diagnosis. Lateral pronotum, prosternum and legs citron yellow to yellowish white ( Fig. 15), in male also with gena yellowish white; thoracic dorsum brilliant green metallic to brilliant golden red (Figs 16,17), with very fine engraved reticulation (Figs 22,26), hence shiny; postmarginal vein 2× as long as stigmal vein (Fig. 20); male scape long (Fig. 27), with almost ½ of length reaching above level of vertex.
Male. Length of body 1.1-1.6 mm. Features as in female except as follows. Antenna with scape with outer surface yellowish white, inner surface with basal ½ white and apical ½ green metallic, narrow in basal ½ and then rapidly expanding towards apex (Fig. 27), elongate with almost ½ the length above the level of vertex; pedicel and flagellum pale brown; pedicel + flagellum 3.3× as long as distance between eyes; flagellomeres 1-4 with scattered setae; clava 1-segmented. Face greenish blue metallic (Fig.  19), smooth; clypeus greenish blue metallic, smooth, rectangular, 2.0× as wide as high; gena yellowish white; lower frons golden to bright golden green (Fig. 19), smooth (Fig. 28); interscrobal area smooth; upper frons red metallic, smooth; vertex golden red.
Petiole yellowish white. Gaster with first tergite golden red, remaining tergites dark brown with metallic tinges, with a pale spot across median part of tergites 1-2, 1.0-1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 479.
Petiole dark brown. Gaster golden with green tinges, short, 1.0× as long as length of mesosoma; 7 th tergite 0.06× as long as length of gaster.

Omphale telephe
Description. Female. Length of body 1.3-2.0 mm. Antenna with scape yellowish brown with dorsal margin dark brown; pedicel and flagellum dark brown; pedicel + flagellum 1.8× as long as distance between eyes; first flagellomere 1.2× as long and 1.1× as wide as second flagellomere (Fig. 51); flagellomeres 2-4 ventrally with two sets of setae, one attached at base and one in apical ⅓ of flagellomere; clava 1-segmented. Face green metallic (Fig. 46), strigose (Fig. 52); clypeus green metallic, smooth or with weak and coarse longitudinal striae, semicircular and 1.9× as wide as high; gena purple metallic or golden purple; lower frons golden green, with raised reticulation; interscrobal area golden, smooth with weak reticulation in upper ⅓; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden green or golden purple with weak reticulation; vertex golden purple to golden red, inside ocellar triangle with engraved weak reticulation, outside triangle smooth (Fig. 53). Occipital margin rounded (Fig. 53).
Petiole yellowish brown to pale brown. Gaster with first tergite golden green, remaining tergites golden purple, elongate and 1.4-1.5× as long as length of mesosoma; 7 th tergite 0.1× as long as length of gaster.
Male. Length of body 1.4-1.8 mm. Features as in female except as follows. Antenna with scape golden green with basal ¼ yellowish white; pedicel + flagellum 2.5× as long as distance between eyes; flagellomeres 1-4 with scattered setae (Fig. 55). Face golden green with part close to eyes golden red (Fig. 47); clypeus golden green, with weak but coarse carinae, shiny, trapezoid; gena purple metallic; antennal scrobes join frontal suture separately (Fig. 56); upper frons golden red, with very weak reticulation and shiny; vertex golden red with purple metallic tinges.
Petiole brown. Gaster with first tergite golden, remaining tergites dark brown metallic, 1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 480.
Description. Female. Length of body 1.4-2.3 mm. Antenna with scape with outer surface yellowish brown, inner surface with basal ⅓ yellow to yellowish white and apical ⅔ pale brown; pedicel and flagellum dark brown and metallic; pedicel + flagellum 2.0× as long as distance between eyes; first flagellomere 1.1-1.3× as long as second flagellomere, at base with same width as second and gradually narrowing towards apex (Fig. 66); flagellomeres 1-3 with ventral setae short, basal setae not reaching apex of flagellomere attached to; longitudinal sensilla on flagellomeres scattered; clava 2-segmented. Face green metallic with golden tinges, to bluish green metallic (Fig. 61), strigose (Fig. 67); clypeus green metallic, to bluish green metallic, smooth, rectangular to trapezoid, 1.2× as wide as high; gena golden red with green tinges, to golden green; lower frons green metallic with golden tinges, with raised reticulation, subtorular area smooth, interscrobal area with raised reticulation; antennal scrobes join frontal suture separately; frontal suture U-shaped; upper frons golden red with green tinges, to golden green with engraved reticulation; vertex golden red with green tinges, with engraved reticulation (Fig. 68). Occipital margin rounded (Fig. 68).
Petiole pale brown to yellowish brown. Gaster with tergite 1 green metallic, tergites 2-7 brown with green, red and golden tinges, elongate and 1.7-2.0× as long as length of mesosoma; 7 th tergite 0.2× as long as length of gaster; 7 th tergite with hairless basal part smooth and apical hairy part sculptured.
Male. Length of body 1.1-1.7 mm. Features as in female except as follows. Antenna ( Fig. 70) with scape long, apical ⅓ reaching above level of vertex, narrow in basal ⅓ and yellowish white, expanded in apical ⅔ which is brown non metallic on outer surface and brown with strong green metallic shine on inner surface; pedicel with same metallic shine as inner upper surface of scape; flagellum brown with golden tinges; pedicel + flagellum 2.7× as long as distance between eyes; first flagellomere 1.2-1.3× as long as second; flagellomeres with scattered setae; clava 1-segmented. Face green metallic (Fig. 62), sometimes with blue tinges; clypeus green metallic, rectangular; gena golden red; lower frons green metallic with golden tinges and upper ⅓ bronze, with raised weak reticulation (Fig. 71); interscrobal area with raised weak reticulation in upper ⅓; upper frons bright golden red and smooth.

Species group salicis
Diagnosis. Forewing with admarginal setae arising from marginal vein, and with radial cell bare and long -extending well beyond postmarginal vein (e.g. Fig. 76); male flagellomeres with verticillate setae and in O. chryseis and O. salicis with setae apical to basal whorl of setae. : phallobase with volsellar setae curved and laterally flattened, not attached on extensions and always crossed in slide mounts but pointed downwards in situ. Species-groups salicis and phruron share diagnostic externomorphological characters and species are difficult to assign to appropriate group using such characters. The best way to diagnose these groups is to use the appearance and orientation of the volsellar setae in the male genitalia.

Morphometric analyses of species in the salicis group
Prior to this investigation five species were included in the salicis group: O. chryseis, O. radialis, O. salicis, O. theana (Graham 1963), and O. acuminata that was described after 1963 also belongs here. Females in this group have been distinguished through the length of gaster, the length of the 7 th gastral tergite, and the number of admarginal setae in forewing (Graham 1959(Graham , 1963. Based on the number of admarginal setae the species can initially be divided into two groups, those with 2-5 admarginal setae (O. acuminata, O. radialis, O. theana), and those with 5-14 (O. chryseis, O. salicis). There is a slight overlap in this character, the mean value for the former group is 3.6, and for the latter 7.8. This subdivision is strengthened by the setation on ventral part of female flagellomeres 2-4, the former group with a single set of setae on each flagellomere, setae attached subbasally, the latter group with two sets of setae, one set attached subbasally, and one medially or subapically.
We have had access to a large number of females of this group and with respect to the length of gaster and of 7 th gastral tergite, two linked characters (females with long gasters also have a long 7 th tergite) we noticed a substantial and what appeared to be continuous variation and therefore decided to analyze this variation. The gaster is difficult to measure and get comparable measurements because it is usually more or less distorted, but the 7 th tergite does not shrivel and can be measured in a comparable way on most specimens. To quantify the variation of this character, measurements of length to the basal width of the 7 th gastral tergite in females were taken and plotted against each other in scatter diagrams (Figs 539, 540), one diagram for each subgroup.
The species O. theana and O. radialis are very similar and were separated by Graham (1959Graham ( , 1963 only through the length of the 7 th gastral tergite and the length of gaster in female: O. theana with 7 th tergite 2.7-4× (3.3× in type of O. theana) as long as its basal width and gaster 2-2.5× as long as mesosoma, O. radialis with 7 th tergite 1.7-2.3× (2.0× in type of O. radialis) as long as its basal width and gaster 1.7-1.9× as long as mesosoma. In the data from specimens of theana/radialis (Fig. 539) the variation of the length of 7 th gastral tergite is continuous and it is not possible to distinguish any clusters. Since there are no other characters by which these species differ we conclude that O. radialis and O. theana belong to one single species with a highly variable gaster length in female. Since O. theana is the older name, O. radialis becomes a junior synonym. Omphale acuminata is very similar to O. theana and differs only in the length of female gaster and thus through the length of 7 th gastral tergite (the male is not known for O. acuminata), but in these species a t-test of the data showed a statistical significant difference.
In O. chryseis and O. salicis there is also considerable variation in the length of the 7 th gastral tergite, and the data also overlap (Fig. 540). Even though O. chryseis on average has a shorter 7 th tergite, the overlap makes it difficult to use this character alone to separate the species, but in combination with the colour of coxae and the WIPs they can be readily distinguished (see below under descriptive part).
To conclude, the length of female gaster and of the length of 7 th gastral tergite show a considerable intraspecific variation in this species group, and great care must be taken when using this character for species separation/identification.
The length of the ovipositor is connected to the length of the gaster, and the variable length of the ovipositor certainly has implications for the ability to parasitize the hosts inside their galls. However, very little is known about the biology of the species in this group.
Description. Female. Length of body 1.2-2.0 mm. Antenna with scape pale brown with base yellowish white and dorsal edge dark brown, to yellowish brown with apical ¼ and dorsal edge dark brown; pedicel and flagellum dark brown; pedicel + flagellum 2.1× as long as distance between eyes; first flagellomere 1.0× as long and 1.3× as wide as second flagellomere (Fig. 40); flagellomeres 2-4 ventrally with one set of setae attached subbasally and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres about as long as flagellomere attached to; clava 2-segmented. Face bluish green metallic (Fig. 74), strigose (Fig. 41); clypeus bluish green metallic, smooth, trapezoid, 1.3× as wide as high; gena pale brown with metallic tinges, to dark brown with green metallic tinges; lower frons bluish green metallic with parts close to eyes and antennal scrobes purple metallic, with engraved strong reticulation, subtorular area smooth; interscrobal area brown with metallic tinges, smooth; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden with engraved weak reticulation; vertex golden green with blue tinges, with engraved very weak reticulation (Fig. 42). Occipital margin rounded (Fig. 42). Mesoscutum bluish green metallic with golden tinges (Fig. 75), with engraved reticulation ( Fig. 39), midlobe with one pair (posterior pair) of setae; anterior ½ of notauli as wide grooves and posterior ½ as indistinct impressions. Scutellum golden with green metallic tinges (Fig. 75), with engraved reticulation (Fig. 39), or dark brown metallic with sides and anterior margin yellowish brown with metallic tinges; 1.2× as long as wide, with anterior margin smoothly curved forwards. Axillae golden (Fig. 75). Dorsellum golden purple (Fig. 75), smooth and slightly convex (Fig. 39), 0.4× as long as wide, and 0.7× as long as length of median propodeum. Lateral pronotum brown with metallic tinges (Fig. 73); prepectus yellowish brown to brown with metallic tinges; mesepisternum yellowish brown with metallic tinges; transepimeral sulcus weakly curved forwards. Propodeum dark brown with golden green tinges (Fig. 75), median part with purple metallic tinges, smooth (Fig. 39); propodeal callus with two setae. Coxae yellowish white to yellowish brown (Fig. 73), hind coxae with base brown with metallic tinges; fore-and midfemora yellowish white, hind femur yellowish brown; tibiae yellowish white; tarsi yellowish white to yellowish brown with 4 th tarsomere darker; midleg with first tarsomere 0.4× as long as length of tarsus. Forewing transparent, veins yellowish brown and setae dark brown ( Petiole yellowish brown. Gaster with tergites 1-6 yellowish brown with posterior margin brown, 7 th tergite brown to dark brown; gaster elongate and 1.6-1.8× as long as length of mesosoma; 7 th tergite 0.6-1.1× as long as its basal width. Male Diagnosis. Legs with fore-and midcoxae predominantly pale and hind coxa predominantly metallic (Fig. 78), femora predominantly brown, tibiae yellowish brown and tarsi predominantly dark brown; female with gaster elongate, 1.7-2.1× as long as length of mesosoma, and with 7 th gastral tergite 1.1-4.2× (average= 1.6, n= 53) as long as width at base; female flagellomeres 1-4 ventrally with two sets of long setae, one attached subbasally and one attached medially or subapically (Fig.  86), male flagellomeres 1-4 each with a basal whorls of setae and with scattered setae apical to whorl (Fig. 90); male scape predominantly dark and metallic; female forewing with 5-12 (average= 7.5, n= 53) admarginal setae, male with 7-9 admarginal setae; head and thoracic dorsum usually bluish green metallic (Figs 79-82). Similar to O. salicis from which it can be distinguished through the colour of coxae -foreand midcoxae pale and hind coxa dark in O. chryseis, all coxae dark in O. salicis; O. chryseis on average has a shorter 7 th gastral tergite in female. These species can also be separated through their WIP in forewings: O. chryseis apical ½ yellow and basal ½ with wide bands in magenta, blue and yellow (Fig. 84), O. salicis has a narrow straight yellow line from stigmal vein to hind margin of wing separating an apical blue and a basal magenta area (Fig. 114).
Description. Female. Length of body 1.4-2.1 mm. Antenna with scape yellowish white with apical ⅓ and entire dorsal edge dark brown; pedicel and flagellum dark brown; pedicel + flagellum 1.9× as long as distance between eyes; first flagellomere 1.1× as long and 1.4× as wide as second flagellomere (Fig. 86); flagellomeres 1-4 ventrally with two sets of long setae, one attached subbasally and one attached medially or subapically; longitudinal sensilla on flagellomeres as long as flagellomere attached to; clava 2-segmented. Face bluish green metallic (Fig. 81), strigose (Fig. 87); clypeus bluish green metallic, smooth or with weak reticulation, semicircular to trapezoid, 1.4× as wide as high; gena greenish blue metallic; lower frons bluish purple to bluish green metallic, with engraved rather strong reticulation; interscrobal area with engraved weak reticulation; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons bluish green metallic with engraved weak reticulation; vertex bluish green metallic, to golden green, with engraved very weak reticulation, partly smooth outside ocellar triangle (Fig. 88). Occipital margin rounded (Fig. 88).
Male. Length of body 1.2-1.5 mm. Features as in female except as follows. Antenna with scape dark brown with blue or green metallic tinges, with basal ⅓-¼ yellowish white; pedicel + flagellum 2.8× as long as distance between eyes; flagellomeres with scattered setae (Fig. 90); clava 1-segmented. Face bluish green to green metallic ( Fig. 82); clypeus bluish green to green metallic, smooth, trapezoid ( Fig. 91), 1.6× as wide as high; gena golden red to golden green; lower frons golden green to bluish green metallic, with engraved and strong reticulation; interscrobal area with weak reticulation; upper frons golden green to bluish green metallic; vertex golden green with red metallic tinges, with engraved weak reticulation (Fig. 92).
Petiole dark brown. Gaster with first tergite bluish green metallic, remaining tergites dark brown to black with golden and green metallic tinges, smooth, 1.1-1.4× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 482.
Distribution. Czech Republic (Bouček and Askew 1968), France (Bouček and Askew 1968), Germany (Gijswijt 1976 Remarks. The description of O. chryseis was based on three female specimens and it is possible that these represent two different species. Graham (1963) described the colour of coxae as "green, pale at apex, or fore-and midcoxae pale testaceous and dark at base only". We have only examined the holotype, not the paratypes, and the holotype has pale fore-and midcoxae, and a dark hind coxa, and this is how we interpret O. chryseis, of which we have examined over a thousand specimens -this species is easily collected when sweeping Medicago. The specimen(s) in the type series with all coxae green is probably O. salicis with a short gaster. Graham distinguished O. chryseis from O. salicis mainly in the length of the female gaster (the male of O. chryseis was unknown to Graham). As shown above, the length of female gaster in these two species is highly variable and cannot be trusted to separate them.  Fig. 102 ; clypeus golden green, smooth, semicircular, 2.0× as wide as high; gena golden green; lower frons with parts between antennal scrobes and eyes bluish purple metallic, with strong reticulation, interscrobal area and parts below level of toruli golden green, with weak reticulation; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden green, with weak reticulation; vertex bluish green metallic, with very weak reticulation (Fig. 103). Occipital margin rounded (Fig. 103).
Mesoscutum bluish green metallic (Fig. 94), with engraved reticulation (Fig. 100), midlobe with one pair of setae (posterior pair); notauli as narrow grooves in anterior ½ and as indistinct impressions in posterior ½. Scutellum bluish green metallic, holotype with lateral parts dark brown with bluish green metallic tinges, one paratype with three wide longitudinal stripes, with lateral stripes pale brown with metallic tinges and median stripe bluish-green metallic (as in Fig. 200), one paratype with scutellum bluish green metallic with anterior corners yellowish brown (Fig. 94); with engraved reticulation (Fig. 100); 1.0× as long as wide, with anterior margin smoothly curved forward. Axillae bluish green metallic (Fig. 94). Dorsellum brown with metallic tinges   Petiole dark brown. Gaster dark brown with bluish green to bluish purple metallic tinges, elongate ovate and 1.2-1.5× as long as length of mesosoma; 7 th tergite short, 0.3× as long as wide and 0.05× as long as length of gaster.
Diagnosis. Female 7th gastral tergite 1.4-4.5× (average= 2.6, n= 109) as long as its basal width; coxae in both sexes predominantly dark and metallic (Fig. 108); female forewing with 6-14 (average= 8, n= 109) admarginal setae, male with 6-12 admarginal setae; female flagellomeres 1-4 ventrally with two sets of long setae, one attached subbasally and one attached medially or subapically (Fig. 116), male flagellomeres 1-4 each with a basal whorl of setae and with scattered setae apical to whorl (Fig. 120). Similar to O. chryseis but with all coxae dark and metallic, and female on average with a longer 7 th gastral tergite. These species can also be separated through their WIP in forewings: O. salicis has a narrow straight yellow line from stigmal vein to hind margin of wing separating an apical blue and a basal magenta area (Fig. 114), O. chryseis has apical ½ yellow and basal ½ with wide bands in magenta, blue and yellow (Fig. 84). Also similar to O. theana but with more admarginal setae in forewing, female flagellomeres 1-4 ventrally with two sets of long setae, coxae predominantly dark and metallic, mesosoma predominantly dark and metallic, scutellum very occasionally with sides brownish; forewing WIPs different: O. salicis with apical and basal halves with different colours (Fig. 114), O. theana with one colour (Fig. 129).
Petiole dark brown. Gaster with first tergite golden green in anterior ½, posterior ½ and remaining tergites dark brown with purple metallic tinges, 0.9-1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 484.
Omphale radialis (Thomson), Hansson (1996b Diagnosis. Female with 7th gastral tergite 1.3-4.3× (average= 2.5, n= 156) as long as its basal width; interscrobal area, prosternum, prepectus and sides of scutellum frequently brownish-testaceous non metallic; coxae yellowish brown to yellowish white ( Fig. 123), base with or without infuscation; forewing with 2-5 admarginal setae; female flagellomeres 2-4 ventrally with one set of setae attached subbasally and reaching beyond apex of flagellomere attached to (Fig. 131); male flagellomeres 1-4 with a single basal whorl of setae (Fig. 135), flagellomere 5 with scattered setae; forewing interference pattern, both sexes, with one colour (Fig. 129) -hue varies depending on size of specimen, which is different from the other species in this group that have different colours on basal and apical halves of the forewing. Very similar to O. acuminata, differs in the length of the 7 th gastral tergite in female, which is longer in O. theana, see above "Morphometric analyses…", and in having a different WIP -forewing with one colour in O. theana (Fig. 129), but with two large areas with different colours in O. acuminata (Fig. 77). Through the elongate female gaster also similar to O. salicis, from which it differs in having fewer admarginal setae in forewing (6-14 in O. salicis), in having coxae predominantly non-metallic, and in WIPs -the unicoloured forewing WIP in O. theana separates it from the other species in this group.
Description. Female. Length of body 1.2-2.3 mm. Antenna with scape yellowish brown with apical ⅓ and dorsal margin dark brown; pedicel and flagellum dark brown; pedicel + flagellum 2.1× as long as distance between eyes; first flagellomere 1.0× as long and 1.0× as wide as second flagellomere (Fig. 131); flagellomeres 1-4 ventrally with one set of setae attached subbasally and reaching beyond apex of flagellomere attached to; clava 2-segmented. Face golden green to bluish green metallic (Fig.  126), strigose (Fig. 132); clypeus golden green with margin towards frons frequently brown, wrinkled to smooth, trapezoid to semicircular, 1.7× as wide as high; gena not visible on type of O. theana but brown with golden tinges in non-type material; lower frons golden green to bluish green metallic, with weak reticulation; interscrobal area pale brown, yellowish brown, or dark brown metallic, smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons golden to bluish green metallic, with very weak reticulation; vertex brown with golden to golden green tinges, with very weak reticulation (Fig. 133). Occipital margin rounded (Fig. 133).
Petiole brown. Gaster dark brown, to yellowish brown with posterior margin of tergites dark brown, and shiny, smooth, elongate and 2.8× (2.0-2.7× in non-type material) as long as length of mesosoma; 7 th tergite 0.3-0.5× as long as length of gaster.
Petiole dark brown. Gaster dark brown metallic, smooth, 1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 485.

Species group phruron
Diagnosis. Forewing with admarginal setae arising from marginal vein, and with radial cell bare and long -extending well beyond postmarginal vein (e.g. Fig. 159); male flagellomeres with verticillate setae, with or without setae apical to basal whorl. Male genitalia: phallobase with volsellar setae more or less straight and attached on long or short extensions, and more or less parallel in slide mounts . Species-groups phruron and salicis share diagnostic externomorphological characters and species are difficult to assign to appropriate group using such characters. The best way to diagnose these groups is to use the appearance and orientation of the volsellar setae in the male genitalia.  (Fig. 144); legs and petiole yellowish brown (Fig. 138), femora frequently dark brown; male flagellomeres 1-4 with basal setae in a whorl (Fig. 151). Similar to O. phruron but with coxae completely pale and shorter gaster in female. Male genitalia: phallobase ( Fig. 486) with volsellar setae on short extensions and with apex of setae 0.4× the length of setae from apex of phallobase, digitus 0.8× as long as wide; aedeagus short and stout (Fig. 486), with penis valves 1.3× as long as wide.
Petiole yellowish brown. Gaster dark brown with golden green and blue metallic tinges, ovate and 1.0-1.4× as long as length of mesosoma; 7 th tergite 0.03× as long as length of gaster.
Mesoscutum with midlobe golden purplish and sidelobes green metallic (Fig.  143). Scutellum golden purple with posterior margin green metallic (Fig. 143). Dorsellum convex with weak sculpture (Fig. 150), 0.5× as long as wide, and 0.4× as long as length of median propodeum. Entire lateral mesosoma dark brown metallic. Propodeum golden green with median part purplish (Fig. 143). Legs with coxae yellowish brown with base infuscate, femora pale brown to dark brown; tibiae yellowish brown; tarsi yellowish brown with apical tarsomere dark brown. Forewing with admarginal setae 7-9, arising from marginal vein and from membrane just behind marginal vein; postmarginal vein 1.5× as long as stigmal vein.
Petiole dark brown. Gaster dark brown metallic, 1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 486.

Omphale clymene
Description. Female. Length of body 1.1-1.6 mm. Antenna with scape yellowish brown with dorso-apical ⅓ dark brown; pedicel and flagellum dark brown; pedicel + flagellum 1.8× as long as distance between eyes; first flagellomere 1.0× as long and 1.3× as wide as second flagellomere (Fig. 162); flagellomeres 1-4 with scattered short setae and ventrally with a set of long setae attached at base and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres as long as flagellomere attached to; clava 2-segmented. Face dark brown with golden tinges (Fig. 157), strigose (Fig. 163); clypeus dark brown with green metallic tinges, smooth, semicircular to trapezoid, 2.0× as wide as high; gena dark brown with golden tinges; lower frons golden with green metallic tinges or spots, purple metallic, or bluish green metallic, with raised weak reticulation; interscrobal area smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons golden red with very weak reticulation, shiny; vertex golden with green tinges to purple metallic, smooth outside ocellar triangle, with very weak reticulation inside triangle (Fig. 164). Occipital margin rounded (Fig. 164).
Petiole yellow to yellowish brown. Gaster with first tergite green metallic, remaining tergites dark brown with golden, purple and green metallic tinges, smooth, elongate and 1.4-1.5× as long as length of mesosoma; 7 th tergite 0.09× as long as length of gaster.
Petiole dark brown. Gaster with tergites 1-5 bluish green metallic with posterior margin golden purple, tergite 6 completely bluish green metallic, tergite 7 completely golden purple, elongate and 1.6-1.9× as long as length of mesosoma; 7 th tergite 0.1× as long as length of gaster.
Petiole dark brown. Gaster with first tergite bluish green metallic, remaining tergites dark brown to golden green, 1.0-1.2× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 488.
Etymology. Name referring to host plant of host. Diagnosis. Mesoscutum and scutellum usually bicoloured in golden purple or purple metallic and bluish green metallic (Fig. 184), and thus similar to O. phruron; female coxae bi-coloured (Fig. 183): brown with at least apices pale (yellowish brown or pale brown), femora dark brown with apices yellowish brown; tibiae yellowish brown (occasionally dark brown). Similar to O. phruron but female gaster shorter, scape predominantly pale (yellowish brown), coxae and femora with apical parts pale (yellowish brown), tibiae usually completely pale, male flagellomeres 1-4 longer and with several setae apical to basal whorl (Fig. 195). Male genitalia: phallobase (Fig. 489) with volsellar setae on long extensions and with apex of setae 0.1× the length of setae from apex of phallobase, digitus 1.6× as long as wide; aedeagus long and slender ( flagellum 1.8× as long as distance between eyes; first flagellomere 1.1× as long and 1.3× as wide as second flagellomere (Fig. 191); flagellomeres 2-4 ventrally with one set of long setae attached subbasally and reaching beyond apex of flagellomere attached to; clava 1-segmented. Face golden purple (Fig. 186), with weak striae (Fig. 192); clypeus golden with purple metallic tinges, smooth, semicircular, 1.8× as wide as high; gena golden purplish; lower frons golden purple, with weak reticulation, subtorular and interscrobal areas green metallic and smooth; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden with purple and green metallic tinges, with very weak reticulation; vertex golden purple, with engraved weak reticulation (Fig. 193). Occipital margin rounded (Fig. 193).
Petiole dark brown. Gaster with first tergite bluish green metallic, remaining tergites dark brown with golden green tinges, ovate and 1.1-1.3× as long as length of mesosoma; 7 th tergite 0.07× as long as length of gaster.
Male. Length of body 0.9-1.3 mm. Features as in female except as follows. Antenna dark brown metallic; pedicel + flagellum 2.5× as long as distance between eyes; flagellomeres 1-4 with verticillate setae and with setae reaching beyond apex of flagellomere attached to, with scattered setae apical to basal whorl (Fig. 195); clava 1-segmented. Face golden red with green metallic tinges, to golden green, strigose; clypeus golden red with green metallic tinges to golden green, smooth, trapezoid to semicircular, 1.6× as wide as high; gena golden purple; lower frons golden red, golden green, or bluish green metallic (Fig. 187); antennal scrobes join frontal suture separately (Fig.  196); upper frons golden red, golden purple, or bluish green metallic, with weak reticulation; vertex dark brown with purple metallic tinges.
Mesoscutum golden red or golden purple with green metallic tinges (Fig. 185). Scutellum with anterior ⅔ golden purple, posterior ⅓ green metallic (Fig. 185), to completely golden purple or purple metallic; 1.3× as long as wide. Some Swedish specimens with mesoscutum and scutellum greenish blue metallic. Dorsellum golden to golden green (Fig. 185), slightly concave and smooth (Fig. 194), 0.4× as long as wide, and 0.5× as long as length of median propodeum. Lateral pronotum golden; prepectus, mesepisternum and mespeimeron dark brown metallic. Legs with coxae and femora dark brown metallic; tibiae pale brown to dark brown; tarsi yellowish brown to pale brown; midleg with first tarsomere 0.3× as long as length of tarsus. Forewing admarginal setae 6-7, arising from marginal vein; stigmal vein slightly enlarged to slender. Petiole dark brown. Gaster with first tergite golden green, remaining tergites dark brown with golden tinges, 1.0× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 489.
Description. Female. Length of body 1.4-1.5 mm. Antenna with scape white with apical ⅓ and dorsal edge brown; pedicel and flagellum dark brown; pedicel + flagellum 1.9× as long as distance between eyes; first flagellomere 1.2× as long and 1.1× as wide as second flagellomere (Fig. 204); flagellomeres 2-4 ventrally with two sets of setae, one attached subbasally and one attached in apical ⅓ of flagellomeres attached to; clava 2-segmented. Face bluish green metallic (Fig. 199), strigose/reticulate (Fig. 205); clypeus purplish green metallic, smooth, semicircular, 2.0× as wide as high; gena dark brown with golden green tinges; lower frons with parts between antennal scrobes and eyes bluish green metallic with strong reticulation, interscrobal area and parts below level of toruli yellowish brown non metallic and smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons golden green, with weak reticulation; vertex dark brown with metallic tinges, with very weak reticulation (Fig. 206). Occipital margin rounded (Fig. 206).
Male. Unknown. Host. Unknown. Distribution. Sweden (Fig. 515). Etymology. Lydia was a Kingdom where, according to Greek mythology, the Queen Omphale once reigned.
Description. Female. Length of body 0.9-1.4 mm. Antenna with scape yellowish brown with dorsal edge brown; pedicel pale brown; flagellum dark brown; pedicel + flagellum 2.1× as long as distance between eyes; first flagellomere 1.1× as long and 1.1× as wide as second flagellomere (Fig. 208); flagellomeres 1-4 with a basal whorl of setae that are distinctly longer than flagellomere attached to, and with a few short and scattered setae apical to whorl; clava ±2-segmented. Face yellow (Fig. 211), with weak reticulation (Fig. 209); clypeus yellow, smooth, semicircular, 1.8× as wide as high; gena yellow; lower frons yellow, with raised reticulation, subtorular area smooth; interscrobal area smooth; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons brown with metallic tinges, with raised reticulation; vertex dark brown with metallic tinges, with very weak reticulation. Occipital margin rounded.
Male. Unknown Host. Unknown. Distribution. France (new record), Sweden (new record), United Kingdom (Graham 1963) (Fig. 517).  Diagnosis. A small species (0.9-1.4 mm) with dark brown scape, coxae and femora (Fig. 228), female gaster elongate (1.6× as long as length of mesosoma) with apex distinctly pointed, mesoscutum and scutellum usually bicoloured in golden purple or purple metallic (occasionally golden red) and golden green or green metallic (Figs 229, 230); female flagellomeres 2-4 ventrally with one set of setae attached subbasaly and reaching beyond apex of flagellomere attached to (Fig. 236), male flagellomeres 1-4 with a basal whorl of setae and with setae reaching beyond apex of flagellomere attached to (Fig. 240), some specimens with a few setae apical to whorl. Male genitalia: phallobase ( Fig. 490) with digitus triangular and 0.6× as long as wide, volsellar setae on long extensions and with apex of setae 1.4× the length of setae from apex of phallobase; aedeagus short and stout (Fig. 490), with penis valves 1.5× as long as wide.
Description. Female. Length of body 1.1-1.4 mm. Antenna dark brown; pedicel + flagellum 1.8× as long as distance between eyes; first flagellomere 1.0× as long and 1.3× as wide as second flagellomere (Fig. 236); flagellomeres 2-4 ventrally with one set of setae attached subbasally and reaching beyond apex of flagellomere attached to; clava 2-segmented. Face dark brown with golden green and purple metallic tinges (Fig.  231), with weak striae (Fig. 237); clypeus golden green, golden red, or purple metallic, smooth, semicircular, 1.8× as wide as high; gena purple metallic; lower frons golden with green metallic tinges, with weak reticulation; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden purple, with very weak reticulation; vertex golden purple, inside ocellar triangle with engraved weak reticulation outside triangle smooth or with very weak reticulation, to completely with engraved weak reticulation (Fig. 238). Occipital margin rounded (Fig. 238).
Petiole dark brown. Gaster dark brown with golden green tinges, elongate and 1.5-1.6× as long as length of mesosoma and with apex distinctly pointed; 7 th tergite 0.1× as long as length of gaster. Male. Length of body 0.9-1.3 mm. Features as in female except as follows. Antenna dark brown metallic; pedicel + flagellum 2.5× as long as distance between eyes; flagellomeres 1-4 with verticillate setae and with setae reaching beyond apex of flagellomere attached to (Fig. 240), some specimens with a few setae apical to whorl; clava 1-segmented. Face golden red with green metallic tinges, to golden green, strigose; clypeus golden red with green metallic tinges, to golden green, smooth (Fig. 241), trapezoid to semicircular, 1.6× as wide as high; gena golden purple; lower frons golden red, golden green, or bluish green metallic (Fig. 232), with weak reticulation; antennal scrobes join frontal suture separately; upper frons golden red, golden purple, or bluish green metallic, with weak reticulation; vertex dark brown with purple metallic tinges.
Petiole dark brown. Gaster with first tergite golden green, remaining tergites dark brown with golden tinges, 1.5-1.6× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 490.
Remarks. Askew (2003) described O. teresis from four female specimens and compared it to O. phruron, which Askew considered the most similar species. According to Askew Omphale teresis differed from O. phruron in having fewer admarginal setae on the forewing, a greener and shinier thoracic dorsum that lacked sculpture on posterior part of both mesoscutum and scutellum, and in having a narrower mesosoma. The female holotype of O. teresis has 7 admarginal setae (i.e. same as lectotype male of O. phruron), the holotype of O. teresis has entire mesoscutum and scutellum reticulate and there are no smooth parts, and the scutellum is bi-coloured with anterior ⅔ golden-purple and posterior ⅓ green metallic, the mesosoma is 1.3× as long as wide (not "at least 1.5×" as stated by Askew). These data contradict the characters given by Askew

Diagnosis.
Female with flagellomeres 2-4 ventrally with one set of long setae attached subbasally and reaching beyond apex of flagellomere attached to (Fig. 225), and first flagellomere distinctly wider than second. Similar to O. phruron but midlobe of mesoscutum with two pairs of setae (Fig. 224); forewing speculum open below (Fig.  246); WIP different, medially with distinct lines (Fig. 247).
Petiole dark brown. Gaster with first tergite golden green, remaining tergites golden with purple tinges, elongate and 1.5-1.6× as long as length of mesosoma; 7 th tergite 0.2× as long as length of gaster.

Diagnosis. Antennal flagellum very slender
Description. Female. Length of body 1.3-1.5 mm. Antenna with scape pale brown with basal part yellowish white and with dorsal edge dark brown; pedicel and flagellum dark brown; pedicel + flagellum 2.6× as long as distance between eyes; first flagellomere 1.1× as long and 1.3× as wide as second flagellomere (Fig. 256); flagellomeres 2-4 ventrally with two sets of setae, one attached at base and one attached in apical 1/3 of flagellomeres; clava 1-segmented. Face golden with green and red metallic tinges (Fig. 251), strigose (Fig. 257); clypeus greenish blue metallic, smooth, trapezoid, 1.9× as wide as high; gena golden purple; frontal cross-ridge present; lower frons golden, smooth or with engraved very weak reticulation, subtorular area smooth; interscrobal area golden green, smooth; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden, smooth or with engraved very weak reticulation; vertex golden purple, close to eyes golden, with engraved reticulation, outside ocellar triangle partly smooth (Fig. 258). Occipital margin rounded (Fig. 258).
Petiole yellowish brown. Gaster pale brown metallic, short ovate and 1.3× as long as length of mesosoma; 7 th tergite short, 0.3× as long as wide and 0.05× as long as length of gaster.
Male. Length of body 1.4 mm. Features as in female except as follows. Antenna with scape expanded, distinctly wider than in female (Fig. 260), dark brown with basal ⅓ yellowish white; pedicel + flagellum 3.1× as long as distance between eyes; first flagellomere 1.2× as long as second; flagellomeres 1-4 with verticillate setae and with setae apical to whorl. Face bluish purple metallic (Fig. 252); clypeus bluish purple metallic, semicircular, 1.5× as wide as high; gena golden with green metallic tinges; lower frons bluish green metallic with purple tinges; interscrobal area with very weak reticulation; antennal scrobes join frontal suture separately; upper frons golden green, smooth; vertex inside ocellar triangle golden purple, outside golden green.
Petiole dark brown. Gaster dark brown, shiny; 1.3× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 491.

Species group aetius
Diagnosis. Forewing with majority of admarginal setae arising from membrane behind marginal vein, and with radial cell hairy (Figs 9,12); frons with surface between lower margin of eye and mouth opening smooth (Fig. 6), sides of clypeus straight, and with a frontal cross-ridge; flagellomeres with short and asymmetric sensilla; male flagellomeres with scattered arrangement of setae (Fig. 4). Male genitalia very distinctive : aedeagus with protruding chitin plates close to apex of penis valves; phallobase with weak volsellar setae and with two extra spines on lateral part of digitus.
The majority of species in this group are impossible to separate morphologically even with some degree of certainty. Apart from four species (O. aethiops, O. connectens, O. dolichura and O. lugubris) with diagnostic enough morphological characters the remainder of the species are inseparable. In previous studies (Graham 1959(Graham , 1963 these species have been separated in the female sex only, males were not possible to distinguish. In the latest study Graham (1963) thus separated the following species in a key: O. acamas (Walker), O. aetius (Walker), O. betulicola Graham, O. coilus (Walker), O. epaphus (Walker), O. grahami Gijswijt (this species was as "sp. indet." in couplet 26, and was later described by Gijswijt (1976) who referred to the Graham key for distinguishing characters), O. phaola (Walker), and O. varipes (Thomson). Graham used the colour of the head, thoracic dorsum and legs; length of gaster, antenna and postmarginal vein; and body size to separate these species. With the large material of this group available for this study, including about 1500 specimens from BMNH (mainly the Graham collection of unidentified Omphale), RMNH (the Gijswijt collection) and material collected in nature for this project, variations in the characters used in the Graham key become evident. These variations are extensive and continuous, and make it impossible to separate the material into morphologically distinct groups. To check if the new characters introduced in this article were useful for species separation in this group, male genitalia and wing interference patterns on a selection of specimens with different colours and/or different measurements were included in the analyses. However, there were no variation in any of these characters, male genitalia were all as in Figs 492-494, and WIPs as in e.g. Fig. 269. Due to the continuous variation of the separating characters used by previous authors the species listed at the end of this group are not included here. However, it is not suggested here that these species represent a single very variable species. There are very probably more than one species among these and in the large material available for this project, but these species are not possible to define morphologically. Because of the uncertainty of the identity of these species no nomenclatural actions including these species are suggested. Such actions have to await future decisions based on studies including other characters than those found in the morphology. Diagnosis. Female gaster very long (Fig. 263), 2.0-2.2× as long as mesosoma, with 7th tergite 1.5-2× as long as its basal width and with posterior ⅔ thickly setose and with each seta usually on a tubercle (Fig. 277) -see remarks below; legs long and slender (e.g. hind tarsus 0.9× as long as hind tibia and 1.1× as long as hind femur) (Fig.  263), with coxae and femora dark; transepimeral sulcus distinctly curved forwards, angular (Fig. 276); body bronze-black; large species (1.9-3.1 mm).
Petiole dark brown. Gaster black with purple metallic tinges, first tergite with anterior ½ with green metallic tinges; elongate and 2.0-2.2× as long as length of mesosoma; 7 th tergite 1.6× as long as length of gaster; 7 th tergite with hairless basal ⅓ smooth and apical ⅔ hairy, each hair usually on a raised tubercle (Fig. 277) but in a few specimens hairs not on tubercle -see below under remarks.
Male. Length of body 1.9 mm. Features as in female except as follows. Antenna with scape expanded (Fig. 275), distinctly wider than in female, yellowish brown with dorsal edge dark brown; pedicel + flagellum 3.2× as long as distance between eyes; first flagellomere 1.1× as long as second flagellomere; flagellomeres with scattered setae; clava 1-segmented. Face green metallic with golden tinges (Fig. 267), smooth; clypeus green metallic with golden tinges, 1.2× as wide as high; lower frons green metallic with golden tinges, with raised very weak reticulation partly smooth; interscrobal area predominantly smooth with raised very weak reticulation in upper ⅓.
Petiole dark brown, as long as wide with anterior part narrowing off. Gaster black with golden and green metallic tinges, 1.3× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 492.
Remarks. In the material under this species there are several females in which the 7 th gastral tergite is smooth and thus without tubercles. No other morphological differences between these specimens and the type of O. aethiops have been found and provisionally these specimens are here regarded as O. aethiops. Diagnosis. Forewing with row of admarginal setae with all, or most, from ventral marginal vein and with radial cell bare (Fig. 283); face shiny with very weak sculpture and partly smooth, to completely smooth (Fig. 287); forecoxa black or dark brown metallic, mid-and hind coxae yellowish brown (Fig. 278); female flagellomeres 1-3 ventrally with two rows of setae, attached basally and subbasally (Fig. 286); postmarginal vein 1.5-2× as long as stigmal vein.
Description. Female. Length of body 1.0-2.4 mm. Antenna with scape yellowish brown with dorsal edge brown; pedicel and flagellum dark brown; pedicel + flagellum 2.4× as long as distance between eyes; first flagellomere 1.1× as long and 1.0× as wide as second (Fig. 286); flagellomeres with scattered short setae, flagellomeres 1-3 ventrally with two sets of setae, one set attached close to base and one attached subapically on the flagellomere; clava 2-segmented. Face purple metallic and golden green, to dark brown with metallic tinges (Fig. 281), with very weak sculpture and partly smooth, to completely smooth (Fig. 287); clypeus green metallic, to dark brown with metallic tinges, smooth, trapezoid to semicircular, 1.4× as wide as high; gena bronze to dark brown metallic; lower frons bronze, with engraved rather strong reticulation, smooth close to eyes, subtorular area smooth; interscrobal area smooth; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons golden green, smooth. Vertex bronze, with engraved reticulation inside ocellar triangle, smooth outside triangle (Fig.  288). Occipital margin rounded (Fig. 288).
Petiole yellowish brown. Gaster with first tergite golden green, remaining tergites golden; elongate and 1.6-2.0× as long as length of mesosoma; 7 th tergite 0.1× as long as length of gaster.
Male. Length of body 1.1-1.4 mm. Features as in female except as follows. Antenna with scape expanded (Fig. 290), distinctly wider than in female, yellowish brown with dorsal and ventral edges dark brown, in some specimens entire inner surface green metallic; pedicel + flagellum 3.5× as long as distance between eyes; first flagel- lomere 1.1× as long as second flagellomere; flagellomeres with scattered setae; clava 1-segmented. Face bright bluish green metallic (Fig. 282), smooth (Fig. 291); clypeus bright bluish green metallic, trapezoid, 1.5× as wide as high; gena purple metallic; lower frons bright bluish green metallic, with engraved very weak reticulation, smooth close to eyes; interscrobal area bright green metallic; upper frons golden purple or bluish green metallic, with engraved very weak reticulation; vertex purple metallic, with engraved weak reticulation (Fig. 292).
Petiole yellowish brown, as long as wide with anterior part narrowing off. Gaster black with golden and green metallic tinges, 1.0-1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 493.
Remarks. Graham (1963) regarded O. connectens as similar to species in the aetiusgroup, but placed it outside the group as a single species because of different setation in the forewing and different sculpture on the head between lower margin of eye and mouth opening. However, the male genitalia, which are very distinctive for speciesgroup aetius, clearly show that O. connectens belongs in the aetius-group.
Petiole yellowish brown. Gaster with first tergite blue metallic, remaining tergites dark brown with golden tinges, elongate and 2.5× as long as length of mesosoma; 7 th tergite 0.2× as long as length of gaster.

Omphale lugubris
Description. Female. Length of body 1.1-1.6 mm. Antenna with scape and pedicel brown, flagellum dark brown; pedicel + flagellum 1.7× as long as distance between eyes; first flagellomere 1.4× as long and 1.0× as wide as second flagellomere (Fig. 314); flagellomeres with scattered short setae, ventral part of flagellomeres 1-3 also with one set of setae attached close to base and reaching beyond apex of flagellomere attached to; clava 2-segmented. Face dark brown with golden tinges (Fig. 309), smooth (Fig.  315); clypeus dark brown with green metallic tinges, smooth, trapezoid, 1.5× as wide as high; gena dark brown with golden tinges; lower frons green metallic with golden tinges, with engraved reticulation, subtorular area smooth; interscrobal area with engraved reticulation; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons green metallic with golden tinges; vertex dark brown with green metallic tinges, with engraved reticulation (Fig. 316). Occipital margin rounded (Fig. 316).
Male. Length of body 1.3 mm. Features as in female except as follows. Antenna with scape expanded, distinctly wider than in female (Fig. 318), inner surface with apical ½ dark brown with metallic tinges and inner ½ yellowish white, outer surface yellowish white with metallic tinges, dorsal edge dark brown; pedicel + flagellum 3.2× as long as distance between eyes; first flagellomere 1.1× as long as second flagellomere; flagellomeres with scattered setae; clava 1-segmented. Face bright bluish green metallic (Fig. 310), smooth (Fig. 319); clypeus bright bluish green metallic, trapezoid, 1.6× as wide as high; gena dark brown and shiny; lower frons golden green, smooth; interscrobal area golden green; upper frons golden, smooth; vertex dark brown with metallic tinges, with engraved weak reticulation (Fig. 320).
Mesosoma, wings and legs as in female. Petiole yellowish brown, as long as wide with anterior part narrowing off. Gaster dark brown with metallic tinges, 1.2× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 494.
Remarks. The lectotype of O. acamas differs from the lectotype of O. aetius in having thoracic dorsum golden green, but this colour is variable in the non-type material examined.
Remarks. Graham (1963) found O. marica difficult to identify and speculated that the type of this species was an aberrant specimen of either O. aetius or O. phaola, or perhaps a species that was difficult to diagnose.
Remarks. Graham (1963) separated O. phaola from the other species in the group through the very weak reticulation on anterior part of mesoscutum. However, it is very difficult to appreciate this character given the fact that there is a variation in it among the non-type material, and there is not much difference between the types of the species in the group. Thomson, 1878:269. Lectotype female in LUZM, examined. Omphale varipes (Walker), Graham (1963).

Derostenus (Omphale) varipes
Remarks. The similarity of the type of this species with the type of O. epaphus was expressed by both Graham (1963) and Askew (2003), something that is also noted here.
Description. Female. Length of body 1.3-1.7 mm. Antenna dark brown to black with metallic tinges; pedicel + flagellum 1.5× as long as distance between eyes; first flagellomere 1.2× as long and 1.0× as wide as second flagellomere (Fig. 329); flagellomeres 2-4 ventrally with a single set of setae attach close to base and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres distinctly shorter than flagellomere attached to; clava 3-segmented. Face golden green with blue metallic tinges (Fig. 324), with strong reticulation (Fig. 330); clypeus yellowish white, smooth, trapezoid, 2.0× as wide as high; gena bluish green metallic; lower frons bluish green metallic, with raised and strong reticulation; interscrobal area reticulate; antennal scrobes join on frontal suture; frontal suture V-shaped; upper frons bluish green metallic, with raised and weak reticulation; vertex golden green with blue metallic tinges, with raised and weak reticulation (Fig. 331). Occipital margin rounded (Fig. 331).
Petiole black. Gaster golden green with blue metallic tinges, smooth. Phallobase and aedeagus as in Fig. 495.
Host. Dasineura brassicae (Diptera: Cecidomyiidae) (e.g. Gijswijt 1976). See above in the introduction for more information on the biology of this species.
Description. Female. Length of body 1.7-2.3 mm. Antenna dark brown with metallic tinges; pedicel + flagellum 1.8× as long as distance between eyes; first flagellomere 1.2× as long and 1.0× as wide as second flagellomere (Fig. 344); flagellomeres 2-4 ventrally with a single set of setae attached close to base and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres distinctly shorter than flagellomere attached to; clava 3-segmented. Face bluish green metallic to golden green (Fig. 339), with weak reticulation (Fig. 345); clypeus pale brown with weak to strong metallic tinges, in some specimens (from Greece and Hungary) golden green to bluish green metallic, smooth, trapezoid to semicircular with ventral margin straight, 1.5× as wide as high; gena golden green; lower frons bluish green metallic, with raised and strong reticulation; interscrobal area reticulate; antennal scrobes join frontal suture separately, or join on frontal suture; frontal suture V-shaped; upper frons golden green, with raised and weak reticulation; vertex golden green, inside ocellar triangle with engraved and weak reticulation, outside with raised and weak reticulation and partly smooth (Fig. 346). Occipital margin rounded (Fig. 346).
Petiole dark brown. Gaster bluish green metallic with tergite 7 golden green, smooth, elongate and 1.9-2.3× as long as length of mesosoma; 7 th tergite 0.1-0.2× as long as length of gaster.
Petiole black. Gaster bluish green metallic with golden tinges, smooth, 1.1× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 496.

Species group sulciscuta
Diagnosis. Body strongly sclerotized and does not shrivel when dried. Head with occipital margin with an edge or a carina; clypeus semicircular or rounded triangular, about as wide as high, not transverse; without frontal cross-ridge; flagellomeres with long and asymmetric sensilla basiconica; male flagellomeres with verticillate setae. Forewing with majority of admarginal setae arising from membrane behind marginal vein, and with radial cell hairy. As treated here this may represent an artificial group, recognized mainly through the strongly sclerotized body and the elongate sensilla on the flagellomeres. The definition of the species groups used here rely quite heavily on characters in the male genitalia. Males are known only for two of the species in this group and the phallobase is very different in these species (Figs 497,498), but the aedeagus is similar (Figs 497, 498) with short penis valves and long apodemes, apodemes 0.6-0.7× the length of aedeagus. [351][352][353][354][355]527 Omphale brevibuccata Szelényi, 1978:222. Holotype female in HNHM, examined. Omphale brevibuccata Szelényi, Askew (2003).
Diagnosis. Vertex green metallic and mesoscutum dark brown (Figs 351-353); mesosomal pleurae yellow (Fig. 351); legs yellowish white to yellow (Fig. 351); frontal cross ridge missing (Fig. 304); antennal scrobes join at or just below frontal suture (Fig.  304); malar space narrow, as narrow as width of scape; first tarsomere on midleg long, 0.4× as long as length of tarsus; flagellum slender and tapering towards apex (Fig. 303), flagellomeres 1-3 ventrally with one set of setae attached close to base and reaching to apex of flagellomere attached to; sensilla on flagellomeres elongate and asymmetric.
Description. Female. Length of body 1.3-1.8 mm. Antenna with scape pale yellowish brown; pedicel and flagellum brown; pedicel + flagellum 2.4× as long as distance between eyes; first flagellomere 1.1× as long and 1.1× as wide as second flagellomere (Fig. 303); flagellomeres with scattered setae and flagellomeres 1-3 ventrally with one set of setae attached close to base and reaching to apex of flagellomere attached to; longitudinal sensilla as long as flagellomere attached to; clava 1-segmented. Face dark brown with golden tinges (Fig. 352), strigose (Fig. 304); clypeus dark brown with golden tinges, with engraved reticulation, semicircular, 1.7× as wide as high; gena purple metallic; frontal cross-ridge absent; lower frons golden with green or purple metallic tinges, with engraved reticulation, subtorular area smooth; interscrobal area smooth; antennal scrobes join at or just below frontal suture; frontal suture V-shaped; upper frons golden, sometimes with purple metallic tinges, with engraved reticulation; vertex bright green metallic to golden green, with engraved reticulation (Fig. 305). Occipital margin with an edge (Fig. 305).
Petiole yellowish white. Gaster dark brown metallic, elongate and 1.6× as long as length of mesosoma; 7 th tergite 0.1× as long as length of gaster.
Description. Female. Length of body 0.9-1.8 mm. Antenna with scape yellowish white with dorsal part yellowish brown; pedicel brown with apex yellowish brown; flagellum brown; pedicel + flagellum 2.1× as long as distance between eyes; first flagellomere 0.9× as long and 1.3× as wide as second flagellomere (Fig. 377); flagellomeres 1-4 with long setae in a basal whorl, with some setae reaching beyond apex of flagellomere attached to, and with short setae apical to whorl; clava 1-segmented. Face dark brown metallic, black metallic, or green metallic (Fig. 372), smooth to strigose (Fig.  378); clypeus with same colour as face, smooth to weakly strigose, triangular, 1.1× as wide (width measured at mouth margin) as high; gena dark brown to black metallic; lower frons with same colour as face, smooth; interscrobal area smooth; antennal scrobes join on or just below frontal suture; frontal suture V-shaped; upper frons dark brown to black metallic with green tinges; vertex dark brown to black metallic with purple tinges, smooth (Fig. 379). Occipital margin with a sharp carina (Fig. 379).
Petiole yellowish brown, dorsal surface 0.7× as long as wide with irregular sculpture. Gaster dark brown to black metallic, smooth, elongate and 1.0-1.4× as long as length of mesosoma; 7 th tergite 0.06× as long as length of gaster.
Male. Length of body 1.2 mm. Features as in female except as follows. Antenna with scape dark yellowish brown with dorsal edge dark brown; pedicel and flagellum dark brown; pedicel + flagellum 1.9× as long as distance between eyes; flagellomeres 1-4 with verticillate setae and with setae reaching beyond apex of flagellomere attached to (Fig. 381); clava 1-segmented. Face bright metallic green (Fig. 373), smooth with striae close to clypeus (Fig. 382); clypeus bright metallic green, weakly strigose, triangular to almost semicircular, 1.4× as wide as high; gena black metallic; lower frons golden with green tinges; antennal scrobes join on frontal suture; upper frons golden, smooth; vertex golden.
Petiole dark brown, as long as wide, narrows off in anterior part. Gaster black metallic, smooth, 1.0× as long as length of mesosoma. Phallobase and aedeagus as in Fig. 498.
Description. Female. Length of body 1.2 mm. Antenna with scape yellowish brown with apical ¼ dark brown; pedicel and flagellum brown; pedicel + flagellum 2.2× as long as distance between eyes; first flagellomere 1.0× as long and 1.4× as wide as second flagellomere (Fig. 366); flagellomeres 1-4 ventrally with a set of long setae attached subbasally and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres setae-like and as long as flagellomere attached to; clava 1-segmented. Face dark brown with strong golden green tinges (Fig. 385), smooth (Fig. 367); clypeus dark brown metallic, smooth, trapezoid, 1.4× as wide (width measured at mouth margin) as high; gena dark brown metallic; lower frons dark brown with strong golden green tinges, smooth; interscrobal area smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons dark brown with metallic tinges, smooth; vertex dark brown with metallic tinges, smooth (Fig. 368). Occipital margin with a sharp carina (Fig. 368).
Petiole hidden in type specimens. Gaster dark brown with weak golden green tinges, smooth, elongate and 1.2-1.6× as long as length of mesosoma; 7 th tergite 0.07× as long as length of gaster.
Male. Unknown. Host. Unknown. Distribution. Russia (Fig. 530). Etymology. Name referring to country of type locality.  . 396); occipital margin with an edge (Fig. 397); antennal scrobes join at or slightly below frontal suture (Fig. 396); mesoscutum with engraved and strong reticulation and with notauli as distinct smooth deep grooves in posterior ⅔, grooves gradually widening towards posterior part (Fig. 394); forewing with row of admarginal setae with all, or most, arising from ventral part of marginal vein and radial cell bare (Fig. 392).
Description. Female. Length of body 1.2-2.0 mm. Antenna with scape pale brown with dorsal margin dark brown, pedicel and flagellum dark brown and shiny; pedicel + flagellum 1.9× as long as distance between eyes; first flagellomere 1.1× as long and 1.3× as wide as second flagellomere (Fig. 395); flagellomeres with scattered short setae, flagellomeres 1-4 ventrally also with a set of long setae attached close to base and reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres as long as flagellomere attached to; clava 1-segmented. Face dark brown with green metallic tinges (Fig. 390), strigose (Fig. 396); clypeus green to blue metallic, strigose, semicircular, 1.4× as wide as high; gena dark brown metallic; lower frons green metallic, with very weak reticulation, almost smooth; interscrobal area smooth; antennal scrobes join at or slightly below frontal suture; frontal suture very weakly V-shaped, almost straight; upper frons and vertex green to blue metallic, sometimes brightly so, smooth (Fig. 397). Occipital margin with an edge (Fig. 397).
Petiole yellowish brown. Gaster with first tergite dark brown with green or blue metallic tinges, remaining tergites dark brown with metallic tinges, smooth, elongate and 1.4-1.6× as long as length of mesosoma; 7 th tergite 0.09× as long as length of gaster.
Male. Unknown. Hosts. Trigonodiplosis sp. (Diptera: Cecidomyiidae) on Vicia cracca (Bouček and Askew 1968). Yefremova et al. (2009) recorded O. rubigus as a parasitoid on Phyllonorycter emberizaepennella and P. pyrifoliella (Lepidoptera: Gracillariidae). In view of the other host record for this species, and host records for other species of Omphale, which are exclusively gall midges (Diptera: Cecidomyiidae), these records are dubious. Presumably the parasitoid is either misidentified, or the samples have been contaminated.
Remarks. Males have never been found in this species, possibly this is a species with thelytokous parthenogenesis.
Description. Female. Length of body 1.1-1.7 mm. Antenna with scape yellowish brown to pale brown with dorsal margin dark brown; pedicel and flagellum dark brown and shiny; pedicel + flagellum 1.3× as long as distance between eyes; first flagel-lomere 1.0× as long as second flagellomere, distinctly wider than remaining flagellomeres, 2.0× as wide as second flagellomere (Fig. 410); flagellomeres 1-4 with setae confined to a basal whorl and with setae reaching beyond apex of flagellomere attached to; longitudinal sensilla on flagellomeres as long as flagellomere attached to; clava 1-segmented. Face black metallic with green tinges (Fig. 405), smooth (Fig. 411); clypeus black metallic with green tinges, smooth, trapezoid to almost semicircular, 1.5× as wide as high; gena black metallic; lower frons black metallic, smooth; interscrobal area smooth; antennal scrobes join below frontal suture; frontal suture V-shaped; upper frons and vertex black metallic, smooth (Fig. 412). Occipital margin with a sharp carina (Fig. 412).
Mesoscutum black metallic (Fig. 403) with engraved reticulation (Fig. 409), midlobe with two pairs of setae; notauli as distinct deep grooves in posterior ½. Scutellum black metallic (Fig. 403) with anteromedian ½ with engraved and weak reticulation, remainder with raised and strong reticulation (Fig. 409), with a distinct median groove in anterior ⅔; 1.2× as long as wide, with anterior margin straight. Axillae black metallic (Fig. 403). Dorsellum black metallic (Fig. 403), tongue like (Fig. 409), smooth and with anterior ½ concave and sharply margined, 0.4× as long as wide, and 0.3× as long as length of median propodeum. Entire lateral mesosoma black metallic (Fig.  402); transepimeral sulcus weakly curved forwards. Propodeum black metallic (Fig.  403), smooth with a wide and shallow groove along anterior margin (Fig. 409), with a narrow median carina, laterally with a longitudinal carina half way between median carina and spiracular sulcus, posteromedian part slightly drawn out to form a short nucha that is delimited anteriorly by a transverse carina; propodeal callus with two setae. Foreleg with coxa dark brown (Fig. 402), femur pale brown, tibia yellowish brown to pale brown, tarsus dark brown; midleg with coxa dark brown, femur pale brown to dark brown, tibia and tarsus yellowish brown to pale brown, first tarsomere 0.2× as long as length of tarsus; hind leg with very base of coxa dark brown to black, remaining coxa pale brown to dark brown, in some specimens the entire coxa is black, femur pale brown, tibia yellowish brown to pale brown, tarsus dark brown. Forewing transparent, veins and setae dark brown (Fig. 407); speculum closed; admarginal setae 8-12, arising mainly from wing membrane; radial cell setose; postmarginal vein 0.7× as long as stigmal vein. Hind wing transparent, apex pointed (Fig. 407). Forewing WIP (Fig. 408) with apical ½ magenta with apical margin yellow, basal ½ with wide bands in blue, yellow and magenta.
Petiole black, quadratic and about as long as wide, to transverse, with anterior part drawn out to a sharp margin that covers propodeal nucha. Gaster dark brown to black and metallic, smooth, elongate and 1.3× as long as length of mesosoma; 7 th tergite 0.04× as long as length of gaster.
Male. Length of body 1.2-1.7 mm. Features as in female except as follows. Antenna with scape dark brown with basal part yellowish white, pedicel and flagellum pale brown; pedicel + flagellum 1.9× as long as distance between eyes; flagellomeres 1-4 with verticillate setae and with setae reaching beyond apex of flagellomere attached to (Fig. 414); clava 1-segmented. Face bright metallic bluish green (Fig. 406), smooth (Fig. 415); clypeus bright metallic bluish green; lower frons bright metallic bluish green; antennal scrobes join frontal suture separately; upper frons bright metallic bluish green; vertex black metallic with blue and green tinges.
Remarks. The male is described here for the first time. Similar to several other Omphale species the sex ratio in the material at hand is skewed with considerably more females than males.
Diagnosis. Gaster short, 0.8× as long as length of mesosoma; forewing speculum open below, with veins and setae yellow; antennal flagellum with basal 2 flagellomeres pale brown and apical 3 flagellomeres yellow (Fig. 422); legs white; row of admarginal setae mainly arising from marginal vein; radial cell bare.
Petiole dark brown. Gaster purple metallic, first tergite with golden tinges, short and 0.8× as long as length of mesosoma; 7 th tergite 0.06× as long as length of gaster.
Description. Female. Length of body 1.4-1.9 mm. Antenna with scape yellowish brown with dorsal margin dark brown; pedicel and flagellum dark brown and shiny; pedicel + flagellum 2.2× as long as distance between eyes; first flagellomere 1.0× as long and 1.0× as wide as second flagellomere (Fig. 431); flagellomeres 1-4 with scattered short setae; longitudinal sensilla on flagellomeres as long as flagellomere attached to; clava 1-segmented. Face purple or green metallic (Fig. 426), smooth (Fig.  432); clypeus purple or green metallic, smooth, poorly delimited with grooves laterally only; gena purple or green metallic; frontal cross-ridge absent; lower frons purple or green metallic, with raised reticulation, smooth close to frontal suture; interscrobal area smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons purple or green metallic with very weak reticulation, shiny; vertex golden with green tinges or green metallic, smooth or with weak reticulation (Fig. 433). Occipital margin with a sharp carina (Fig. 433).
Remarks. The character-set present in this species (see diagnosis above) is unlike any other species in the genus, and the appearance of the male phallobase is also unique. These features makes it difficult to assess O. erginnus to any of the species-groups. Diagnosis. Small species (0.7-1.1 mm); body dark brown with metallic tinges (Fig. 438); midlobe of mesoscutum with one pair of setae (posterior pair) (Figs 445,449); forewing with long marginal fringe, e.g. setae along outer margin are 0.3× as long as width of wing, and a very short postmarginal vein (Fig. 443); head smooth (Figs 447,448,451,452); vertex with distinct sulci between ocelli and eyes (Figs 448,452); clypeus with median part of ventral margin drawn out into a rounded point (Figs 447,451); male antenna with scape with basal 2/3 gradually expanding towards apical part and then abruptly narrowing off (Fig. 450).
Description. Female. Length of body 0.7-1.1 mm. Antenna with scape and pedicel yellowish white; flagellum pale brown with metallic tinges; flagellum long and slender, pedicel + flagellum 2.6× as long as distance between eyes; first flagellomere 0.9× as long and about 1.2× as wide as second flagellomere (Fig. 446); flagellomeres with few long and scattered setae; longitudinal sensilla very long and setae-like but thicker and paler than setae; clava 1-segmented. Face dark brown with metallic tinges (Fig.  441), smooth (Fig. 447); clypeus dark brown with metallic tinges, smooth, rectangular but with lower margin protruding and with median part more or less pointed; 2.0× as wide as high; gena dark brown with metallic tinges; frontal cross-ridge absent; lower frons dark brown with metallic tinges, smooth, subtorular area smooth; interscrobal area smooth; antennal scrobes join frontal suture separately; frontal suture V-shaped; upper frons and vertex dark brown with metallic tinges, smooth (Fig. 448). Occipital margin with a carina (Fig. 448).
Designation of neotype. Apart from specimens collected by Nees now in the Haliday collection in Oxford, all specimens of the Nees collection have been destroyed (Graham 1988). As there are no specimens of Eulophus lugens in Oxford (Graham 1988) this species is therefore not fixed by any type material. To maintain a stable nomenclature a neotype for E. lugens is designated here. As neotype a female from Germany: Bavaria, Obersdorf, reared from Mikiola fagi is selected. The material from the original description was from Sickershausen, which is in Bavaria in Germany, collected from a window. The neotype agrees well with the original description.
Petiole dark brown. Gaster with first tergite bluish green metallic, remaining tergites dark brown with metallic tinges, elongate and 1.2-1.5× as long as length of mesosoma; 7 th tergite 0.06× as long as length of gaster.
Remarks. Externomorphologically O. lugens fits best in the same group as O. phruron, something also suggested by Graham (1963). However, if male genitalia are considered, a character-set unknown to Graham, then O. lugens is something quite unique and far removed from the species in the phruron-group. Omphale melinum Yefremova & Kriskovich, 1994:247. Holotype female in ZISP, not examined.
Mesosoma yellow with setae on thoracic dorsum black (Fig. 470). Mesoscutum with engraved weak reticulation, midlobe with two pairs of setae (Fig. 470); notauli as indistinct impressions. Scutellum with engraved weak reticulation; 1.2× as long as wide, with anterior margin weakly curved forwards. Dorsellum smooth and slightly convex, 0.4× as long as wide, and 0.8× as long as length of median propodeum. Propodeum smooth; propodeal callus with two setae. Lateral mesosoma yellowish white (Fig.  468); transepimeral sulcus curved forwards. Legs yellowish white (Fig. 468); midleg with first tarsomere 0.4× as long as length of tarsus. Forewing transparent with infuscate areas around stigmal vein and below base of marginal vein (Fig. 471), veins yellowish white and setae dark brown; speculum closed; admarginal setae 5, arising from marginal vein; radial cell bare; postmarginal vein 1.0× as long as stigmal vein; stigmal vein enlarged and circular. Hind wings missing in single examined specimen. Forewing WIP (Fig. 472) unicoloured purple with a small round area just below stigmal vein in blue and yellow.
Petiole yellow. Gaster pale brown with five yellow cross bands, 7 th tergite and apical parts of ovipositor sheaths black metallic; elongate (Fig. 468) and 1.7× as long as length of mesosoma; 7 th tergite 0.1× as long as length of gaster.
Male. Unknown. Hosts. Unknown. Distribution. Russia (Yefremova and Kriskovich 1994) (Fig. 537). Remarks. The examined paratype specimen is damaged. It lacks the entire right antenna and of the left antenna only the scape remains; both hind wings are missing; the gaster has been gnawed upon and parts of the left hand side are gone. In spite of this the species is easy to recognize through its non-metallic body and enlarged stigmal vein. The species is difficult to assign to a specific group, when males are found these may hold morphological clues as to its placement.
Petiole yellowish brown. Gaster yellowish brown with posterior margin of tergites brown, apical parts of ovipositor sheaths dark brown (Fig. 473), smooth; elongate and 2.0× as long as length of mesosoma; 7 th tergite 0.2× as long as length of gaster.   Male. Unknown. Host. Unknown. Distribution. Sweden (Fig. 538). Etymology. From the Greek ochros = pale yellow, referring to the predominant colour of the body.
Remarks. Both type specimens are shrivelled, thus measurements and ratios are not exact. Known only from shrivelled females this species is difficult to place to group. Characters involving the setation in forewing suggest an affinity to either phruron-or salicis-group. When males are found a firmer idea on this can be established.

Other European species associated with Omphale
Two additional species from Europe, Pholema microstoma Graham and Eugerium orbatum Szelényi, were associated with Omphale prior to this revision. Their association with Omphale is because the genus they were originally described in, Eugerium and Pholema respectively, were synonymized with Omphale. However, new data presented here suggest a different classification of these species.
Genus Pholema Graham, stat. rev. http://species-id.net/wiki/Pholema Remarks. Graham (1963) described genus Pholema to include the single species microstoma, which was described in the same paper. Graham motivated the new genus because he regarded some morphological features present in Pholema: small clypeus, large malar space, small mouth opening, too discordant for an Omphale species. Schauff (1991) synonymized Pholema with Omphale because he found the characters mentioned by Graham too variable and/or overlapping with some Omphale species.
The type species and the only known species of Pholema, P. microstoma, has the following characters important for classification on genus level: clypeus undelimited (Fig.  543), occiput without a groove or fold between occipital margin and occipital foramen (Fig. 541), sensilla ampullacea (peglike sensilla) on flagellomeres short and symmetric (Fig. 542), forewing with postmarginal vein 0.8× as long as stigmal vein, ovipositor very short -gaster short and rotund and ovipositor only ½ as long as length of gaster, male genitalia with volsellar setae as "normal" thin setae. Some of these characters disagree with a placement of P. microstoma in Omphale: undelimited clypeus, antennal sensilla symmetric, and perhaps the most critical -not having enlarged volsellar setae in male  genitalia, the sole autapomorphy for Omphale. Habitually P. microstoma looks like a Neochrysocharis Kurdjumov, mainly because of the distinct and 3-segmented antennal clava and the short postmarginal vein, and some additional characters also agree with a placement in Neochrysocharis (undelimited clypeus, symmetric antennal sensilla). Absence of an occipital groove/fold is very unusual in Neochrysocharis but it is absent in at  least one other species, N. albiscapus Erdös. Furthermore, this character state is variable within Neochrysocharis, some species have a complete fold between occipital margin and occipital foramen, while others only have a short fold close to the occipital margin, and as mentioned some species lack it altogether. Therefore the absence of such a fold does not justify a separate genus for P. microstoma. The short ovipositor, not present in other Neochrysocharis species (nor in any Omphale species), is probably an adaptation to a close access of the host, and doubtfully of such a value that it justifies a separate genus. Another option is to place P. microstoma in Asecodes Förster, but some critical characters disagree with such a placement. Pholema microstoma has symmetrical antennal sensilla, a distinct 3-segmented antennal clava and lacks a fold or groove on occiput; Asecodes species have asymmetric antennal sensilla, a 1-segmented antennal clava and a strong groove between occipital margin and occipital foramen. All things considered P. microstoma is a Neochrysocharis and Pholema is thus a synonym of Neochrysocharis.
additional material we also thank T. Gijswijt (the Netherlands) and T. Munk (Denmark). The Swedish Malaise Trap Project, that is funded by the STI, has contributed with freshly collected material, and all people who have been working with the collecting and sorting of malaise trap material are acknowledged for their work. We further express our thanks to the Biology Department at Lund University, Sweden, for use of their SEM facilities.