A new species of Pseudochalcura ( Hymenoptera , Eucharitidae ) , with a review of antennal morphology from a phylogenetic perspective

Pseudochalcura alba Heraty & Heraty, sp. n. is described from Santiago del Estero and Catamarca provinces in northwestern Argentina. Th e male and female have long dorsal rami on all of the fl agellomeres basal to the terminal segment, which is a unique feature within the genus and shared only with some species of Rhipipalloidea. Antennal modifi cations are compared across the Stilbula clade, of which all are parasitoids of Camponotini (Formicinae). A phylogenetic hypothesis for the group is proposed based on an analysis of 28S and 18S sequence data for 28 species. Ramose antennae are derived independently in both males and females across the clade, but with fully ramose female antennae restricted to the New World prolata group of Pseudochalcura and to some species of the Old World genus Rhipipalloidea. A sister group relationship between these genera is proposed based on both morphological and molecular data. Female antennae in other species of these genera, and other genera in the clade are at most dorsally lobate or serrate, but more commonly cylindrical. Monophyly of species of Obeza and Lophyrocera is supported and linked to a behavioral trait of oviposition into fruits as opposed to fl ower heads or leaf buds. Within the Stilbula clade, a dichotomy between New and Old World taxa suggest relatively recent post-Miocene exchanges across the Northern Hemisphere.


Introduction
Eucharitidae (Hymenoptera: Chalcidoidea) are parasitoids of ant pupae (Clausen 1940, Heraty 2002).A variety of methods are employed to gain access to the ant brood, but all involve oviposition outside of the nest and the active transport of the fi rst-instar planidial larva.Th e Stilbula clade is a distinct group within the Eucharitini (Eucharitidae: Eucharitinae), with all known host records from Camponotini (Formicinae) (Clausen 1940, Heraty 2002).Oviposition within this group is either in large egg masses that resemble fruit, or into the skin of fruits themselves, thus introducing larvae into the foraging proximity of their hosts (Clausen 1940;Heraty andBarber 1990, Torréns et al. 2008).Based on morphology, the clade is either monophyletic or paraphyletic (Heraty 2002), but monophyletic for either molecular data alone (28S and 18S) or in combination with morphological data (Heraty et al. 2004).Pseudochalcura exemplify the behavior typical of the clade and are the focus of this paper, along with the description of a species with unusual antennal features for both the genus and family.
Pseudochalcura are comprised of 10 recognized species that range in the New World from Chile and Argentina to the Yukon and Alaska, although several new species have been discovered since their fi rst revision (Heraty 1986, JMH unpublished).Pseudochalcura gibbosa (Provancher) oviposit masses of 1000-2000 eggs into leaf buds of various Ericaceae and Malvaceae (Cook 1905;Pierce and Morrill 1914;Clausen 1940;Heraty & Barber 1990).Eggs of this species overwinter in the leaf bud and likely fall to the ground as the buds expand and the bud scales drop in the spring.Simultaneous hatching of the egg mass upon stimulation by the host ant is seen as a means of both attracting ants (recruitment) and for gaining transport back to the ant brood as a food resource (Heraty and Barber 1990).First-instar planidial larvae of P. gibbosa initially attack larvae of Camponotus novaeboracensis (Fitch), with development completed by one to three individuals on a single host pupa (Wheeler 1910;Heraty and Barber 1990).Th e only other confi rmed host record is for P. nigrocyanea Ashmead from Brazil, for which adults were observed exiting from a nest of Camponotus and ovipositing into fl ower buds of an unidentifi ed Rosaceae (Heraty unpublished).Deposition of egg masses into fl ower buds is shared with Stilbula (Clausen 1940) and Substilbula (Heraty, unpublished), and is likely a plesiomorphic behavior for the Stilbula clade with oviposition into fruit regarded as a derived behavior (Heraty and Barber 1990;Torréns et al. 2008).
Th e form of the antennal fl agellum in Eucharitidae is highly variable, ranging from cylindrical or lobate, serrate or ramose in both males and females (Heraty 2002).Antennae may be simple to serrate, with single long rami on the fl agellomeres, or with paired elongate rami as found in some species of Saccharissa and Chalcura (Heraty 2002).Antennal rami can be either cylindrical, fl attened, or even antler-like as in Tricoryna alcicornis Bouček (Bouček 1988;Heraty 2002).Some genera even have an increased number of fl agellomeres, with Eucharissa erugata Heraty having as many as 18.Morphological diversity in the antennal fl agellum is restricted to the tribe Eucharitini, with all other Eucharitidae (Oraseminae, Gollumiellinae, and Psilocharitini [Eucharitinae]) having simple, cylindrical fl agellomeres.Ramose antennae are independently developed in various clades within Eucharitini, and, in males, often fi xed within larger groups such as in virtually all of the poneromorph parasitoids.Similar morphological changes are rare within females, which often have at most dorsally serrate antenna.Th e Stilbula clade is unique in its extreme level of antennal variation which is paralleled in both males and females.Also notable is a similar amount of antennal variation within Pseudochalcura.Only within the Stilbula clade do the female antennae have the same diversity of form as the males.Th e variation has not been examined previously from a phylogenetic perspective in a closely related group to observe whether changes are homoplastic or synapomorphic.Herein we describe the extreme variation possible in a new species and an undescribed species of Rhipipalloidea, as well as resolution of these changes on a phylogeny proposed for members of the Stilbula clade.We also discuss changes in their behavior and correlated biogeographic considerations.

Materials and methods
Terms for descriptive purposes follow Heraty (2002).Images were obtained using GT-Vision® Ento-Vision software operating on a Leica M16 zoom lens linked to a JVC KY-F75U 3-CCD digital video camera.Images were enhanced with Adobe Photoshop CS2.Museums for deposition include the Entomology Research Museum, University of California Riverside (UCRC) and the Instituto Fundación Miguel Lillo, Tucumán, Argentina (IFML).Images for antenna of other species of  are based on a variety of material, with information on locality and specimen deposition available from the senior author upon request.Th e undescribed species of Rhipipalloidea is from Tenompok (Sabah, Malaysia) and is deposited in the Bishop Museum.Illustrations of antennae in Fig. 23 were redrawn from Heraty (1985Heraty ( , 2002)).
Molecular Analyses -Th irty-four individuals were sequenced representing 28 species of Eucharitinae (Eucharitidae), with three species of Pseudometagea selected as the outgroup (Table 1).Pseudometagea are parasitoids of Lasiini (Formicinae) and restricted to the Nearctic Region and Central America (Heraty 1985).Th e remaining 7 genera are included in the Stilbula clade of parasitoids of Camponotini (Heraty 2002).Conspecifi c individuals with identical sequence were eliminated from the analysis but indicated on Fig. 23.Th e complete matrix included 30 terminal taxa.Voucher specimens, except where indicated as "not available", are deposited at UCRC (Table 1).
Analysis -Parsimony analyses were implemented using PAUP*4.0b10 (Swoff ord 2002) using 500 random-addition heuristic searches and TBR branch swapping.Uninformative sites were included in all analyses.Gaps were treated as missing.Trees were condensed for branches with a minimum length of zero.Successive approximation character weighting was applied to the resulting trees using the maximum value of the rescaled consistency index and a base weight of 1000, with the resulting tree rescaled to unity character weights and compared in length to the most parsimonious trees (Carpenter 1988;Heraty et al. 2004).Bootstrap values for parsimony analyses were evaluated with 1000 random replicates and 2 random addition searches per replicate.In addition, a second partitioned likelihood analysis was performed using RaxML with three partitions and 200 rapid bootstrap replicates (Stamatakis et al. 2008) as implemented on the CIPRES server (http://www.phylo.org/sub_sections/portal/).Each partition was analyzed under a separate GTR+I+Γ model as applied in Heraty et al. (2004).

Description
Pseudochalcura alba Heraty & Heraty, sp.n. urn:lsid:zoobank.org:act:97405532-D55F-449C-9303-2F8BDFE1137EFigs 1-9 Diagnosis.Th is is the only species of Pseudochalcura in which the male has fl agellomeres 1-9 each with a long branch, the female has a long branch on fl agellomeres 1-7, and both sexes have a 10-segmented fl agellum.Th is species is placed in the condyla group of species based on the bare wing veins, sculptured (strigate) gastral sternite 1 in the female, absence of a metatibial spur, and ramose female antenna (to couplet 11 in Heraty 1986).No other member of this group has a 12-segmented female antenna or completely ramose male antenna.Th e closest species is considered to be P. prolata Heraty (Argentina: Chaco Province), which has the basal 5-7 fl agellomeres of the female antenna each with a stout branch, and a maximum of 8-11 antennal segments (male unknown).Th e basal branch of the female of P. prolata is stouter and 5.4 times as long as the basal length, as compared to 6.2 times in P. alba.Male (Holotype).Length 2.35 mm.Black with faint metallic luster; scape, pedicel, mandible, petiole, and basal quarter of femora light brown; antennal fl agellum and rest of legs white.Wings hyaline, stigma clear.
Head 1.79 times as broad as high (Fig. 4).Posterior ocellar line (POL) 2.8 times lateral ocellar line (LOL); POL 3.3 times ocellar ocular line (OOL).Frons and face irregularly costate (Fig. 4); clypeus and supraclypeal area smooth; genal bridge emarginate behind the mouthparts.Eyes separated by 2.2 times their height.Malar space 1.1 times height of eye, malar depression absent.Apical tooth of mandible long and overlapping opposing genal area.Labrum not observed.Antenna 12-segmented (Fig. 4); scape short and cylindrical, not reaching to median ocellus; all fl agellomeres but the last with long branches ranging from 7.4 to 12.3 times as long as basal length, fl agellomere branches alternating in origin from the base and slightly fl attened; apical fl agellomere unbranched and 3.6 times longer than broad; fl agellomeres with dense short setae, and multiporous plate sensilla small and recessed into depressions of the antennal wall.Mesosoma mostly with areolate sculpture, interstices broad with verrucose sculpture (Figs 2, 3, 5).Mesoscutum 2.0 times as broad as long; scutoscutellar sulcus transverse and deeply foveate; scutellar-axillar complex 1.4 times as long as maximum width of scutellum.Propodeal disc slightly rounded with broad alveolate sculpture medially and a few scattered setae dorsally, disc laterally relatively smooth; callus and metapleuron alveolate.Femoral groove deeply impressed.Proepisternum rugulose, becoming smooth apically.Mesocoxa weakly sculptured and lacking a lateral carina; metacoxa mostly smooth, laterally with small scattered pits.Legs stout (Figs 1, 2, 3), metafemur expanded medially, 3.5 times as long as broad; with short sparse appressed setae later- Figures 2-9.Pseudochalcura alba sp.n.: 2-5 male holotype: 2 lateral habitus 3 mesosoma, lateral 4 head, frontal 5 mesosoma, dorsal 6-9 female paratype: 6 antenna, lateral 7 head, frontal 8 mesosoma, dorsal 9 habitus, lateral.Inset is magnifi cation of mesoscutal sidelobe.ally; metatibia with sparse semi-erect setae dorsally and dense appressed setae ventrally; metatibial spur absent.Forewing 1.9 times as long as broad; costal cell 0.31 times as long as wing, without setae; submarginal vein and basal area of wing bare; wing veins clear and diffi cult to discern beyond submarginal vein, stigma elongate oval and about 4 times as long as broad; disc of wing with microsetae ventrally.Hind wing broad and apically rounded, 3.4 times as long as broad.
Petiole 2.7 times as long as broad in lateral view, 1.6 times as long as metacoxa (Fig. 3); very slightly curved in profi le; bare with fi ne granulate sculpture.Gaster globose, fi rst tergite (Gt 1 ) 1.7 times as long as broad, smooth with few short setae dorsally; fi rst gastral sternite smooth.
Female (Paratype; diff erences from male).Length 3.72 mm.Dark brown to black with faint metallic luster; antenna, mandible, petiole and basal two thirds of femora brown; rest of legs light brown.
Mesosoma with areolate sculpture, interstices narrow and smooth (Figs 8, 9, and inset).Mesoscutum 2.1 times as broad as long; scutellar-axillar complex 1.1 times as long as maximum width of scutellum.Propodeal disc fl at with broad alveolate sculpture medially, disc laterally areolate (Fig. 9).Metafemur 3.4 times as long as broad.Forewing 2.1 times as long as broad; costal cell 0.31 times as long as wing.Hind wing 3.4 times as long as broad.

Phylogenetic Results
Only two genera of the Stilbula clade (sensu Heraty 2002) were not included in these analyses.Neostilbula (Madagascar) is now considered as a member of the Eucharis clade in the Eucharitini (Heraty unpublished).Specimens of Striostilbula (Australia) were not available for molecular analysis, although its placement in the Stilbula clade is based on weak morphological support and its inclusion is suspect (Heraty 2002).Parsimony analysis of the 7 genera in the Stilbula clade resulted in a single tree (247 steps, r.i.0.88; Fig. 23).Successive approximations weighting generated the same tree, suggesting the data provide stable results (Carpenter 1988).Bootstrap support was high for most nodes across the tree.Th e RAxML results provided nearly the same tree topology, but with Stilbuloida sister group to the rest of the Stilbula clade; however the RAxML bootstrap results supported a monophyletic Stilbuloida + Stilbula (100%; Fig. 23).Th e RAxML results also placed P. gibbosa as sister group to the P. americana clade, but with almost no bootstrap support (52% as compared to 51% for the placement on the parsimony tree (Fig. 23).For Pseudochalcura, the results presented in Fig. 23 are more concordant with the morphology-based phylogeny presented in Heraty (1986).Relationships within and among the other genera were the same in both results (Fig. 23).
Two groups occur within the Stilbula clade (Fig. 23): (A) Leurocharis (Australian), Substilbula (Australian), Rhipipalloidea (Indoaustralian) and Pseudochalcura (New World); weak parsimony bootstrap support (52%), but strong RAxML bootstrap support (99%); and (B) Stilbuloida (Australian), Stilbula (Old World), Obeza and Lophyrocera (both New World); strong parsimony bootstrap support (100%) but not monophyletic in RAxML.Genera in group B all share a bare callar region on the mesosoma, and usually have strong transverse carinae on the lower face.Sister group relationships between Rhipipalloidea + Pseudochalcura and Lophyrocera + Obeza have been proposed based on both morphological and molecular data (Heraty 2002;Heraty et al. 2004).Rhipipalloidea and Pseudochalura have the postgenae or hypostomae forming a complete bridge posterior to the mandibles in association with a reduction of the maxillary complex (Heraty 2002), and monophyly of Obeza and Lophyrocera share strong projections on the propodeum and callus (Heraty 2002).Based on morphology, Leurocharis was treated as either a sister group to all of these genera when monophyletic, or excluded when paraphyletic (Heraty 2002).Subsequent analyses of an even larger molecular data set consistently put all of these Stilbula clade genera together in a monophyletic group (Heraty unpublished).
Th e new species, P. alba, is placed together with P. prolata Heraty (Fig. 23, grey box).Pseudochalcura prolata was placed by Heraty (1986) with two other species, P. condylus Heraty and P. sculpturata Heraty, in the prolata species group based on six synapomorphies, including males having 7 basal rami on the antennal fl agellomeres, the fi rst gastral sternite striate, and lack of a metatibial spur, which are all features shared with P. alba.Pseudochalcura alba is the only male with rami on all fl agellar segments, including an elongation of the terminal segment (Fig. 4).Females of P. alba, P. sculpturata, and P. prolata have at least the basal fl agellomeres ramose (Figs 6,14,23g).Females of all other species of Pseudochalcura have either cylindrical or at most dorsally serrate antennae (Figs 10,12,16,23e).Based on the lack of costal cell setae, P. pauca was treated as a potential sister group of the prolata group, but it has serrate, not ramose, antennae (Fig. 23f ); the male is unknown (Heraty 1986).Pseudochalcura gibbosa, along with P. septuosa Heraty and P. atra Heraty, was proposed as the sister group of P. pauca + the prolata group (Heraty 1986), which is consistent with the current results (Fig. 23).Males of the P. americana clade herein and P. gibbosa have only the basal 4-6 fl agellomeres ramose (Figs 11,13).Based on the phylogenetic hypothesis presented in Fig. 23, in males, a fl agellum bearing 4-6 basal rami originating along the dorsal midline is considered plesiomorphic for the genus (Figs 11,13), whereas a fl agellum with 7-9 rami, with an alternating origin along the midline (Figs 4,15,17,18) is apomorphic within Pseudochalcura.
Females of Rhipipalloidea from Australia have either simple cylindrical fl agellomeres as in R. gruberi (Girault) (Fig. 19), dorsally serrate fl agellomeres as in R. mira (Girault) (Fig. 20), or completely ramose fl agellomeres as in several undescribed species from Sarawak (Fig. 21), Vietnam, and the Philippines.One undescribed species from Mudigere (western India) has dorsally serrate fl agellomeres.Males of all species of Rhipipalloidea have long dorsal rami on fl agellomeres 1-7 (Figs.22, 23d).Female rami always originate along the midline, whereas male rami have alternating sites of origin.Th us the range of antennal morphology in these Australasian species parallels the diversity found in their New World sister group.

Discussion
Th e two groups proposed on the basis of morphological and molecular evidence not only revise our understanding of the evolutionary history of the group, but also suggest evolutionary character transitions that are of particular interest in the Eucharitidae.Four unusual evolutionary changes across the group are of particular interest within the family: coloration of the head and mesosoma, fusion of the postgenal area behind the mouthparts, a shift in oviposition habits from leaf buds to fruit, and morphological changes in the male and female antennae.
A yellow-patterned coloration of the mesosoma with contrasting black to dark green or blue patches is rare within Eucharitidae and occurs only within the Stilbula clade and some species of the eucharitine genus Eucharis (Heraty 2002).Among related Chalcidoidea, a similar color pattern occurs only within the distantly related Philomidinae (tentatively placed within Perilampidae).Within the Stilbula group A, only Pseudochalcura sculpturata Heraty (prolata group, gray box, Fig. 23; P. prolata not included on tree) has a yellow and black patterning of the mesosoma, with other species either brown, black, or black with faint metallic tints.Each of the genera in group B (Stilbuloida, Stilbula, Obeza and Lophyrocera) have some or all species with a black and yellow pattern on the mesosoma (Heraty 2002).Among these species, the base color of the mesosoma is almost always yellow, with a general orange color found only in Obeza fl oridana (Ashmead) (Heraty 2002).Coloration can be highly variable, with individuals of a species at a single locality ranging from almost completely black or metallic blue to mostly yellow (e.g.Stilbula septentrionalis (Brues), Heraty 1985;Lophyrocera variabilis, Torréns et al. 2008).Based on outgroup comparison across Eucharitidae, a uniformly brown, black or metallic mesosoma is plesiomorphic.Th erefore a yellow In Pseudochalcura and Rhipipalloidea, the postgenae are completely fused as a transverse bridge posterior to their highly reduced maxillary complex.In Substilbula, the hypostomae are fused dorsally just below the foramen, but with the postgenae widely separated and the maxillary complex slightly reduced (fi g. 338, Heraty 2002).In Obeza, Lophyrocera, Leurocharis and Substilbula, the postgenae are strongly produced medially and narrowly separated, but never fused and the maxillary complex is not reduced (Heraty 2002).Only in Stilbuloida, Stilbula and Striostilbula are the hypostomal and genal lobes broadly separated and maxillary complex fully developed as in other Eucharitidae.Mouthparts are reduced in a few other eucharitids (e.g.Indosema indica Husain & Agarwal and Pseudometagea nefrens Heraty), but without a correlated extension of the postgenae.Outside of the Stilbula clade, only Orasema simulatrix Gahan (Eucharitidae: Oraseminae) has the postgenae strongly produced, but without the corresponding reduction of the maxillary complex.None of the hypotheses for fusion of the postgenae in the Stilbula clade, either herein or based entirely on morphology (Heraty 2002) support a linear transformation series for the fusion of the genae from broadly separated, to closely associated, to completely fused.Instead, multiple independent origins of each of the two derived character states is supported.
Obeza and Lophyrocera are the only eucharitids known to oviposit small batches of eggs (60-100) under the epidermal layer of small fruits; other members of the Stilbula clade oviposit into existing cavities within leaf or fl ower buds (Fig. 23; Heraty  Heraty 1986Heraty , 2002)).Red line is development of dorsal rami on female antenna; blue line is development of dorsal rami on male antenna.Clades A and B marked.Species names are followed by country codes and DNA voucher number (see Table 1).1990;Heraty 2002;Torréns et al. 2008).Th e outgroup for our analysis, Pseudometagea, oviposit into cavities in the seed heads of Poaceae (Heraty and Darling 1984), and most Eucharitini oviposit into fl ower buds or scatter their eggs on the leaf surface (Heraty 2002).Fruit oviposition and the direct association with a frugivorous ant host is unique (Heraty and Barber 1990).Across the Stilbula clade behaviors range from oviposition by Pseudochalcura of large masses of eggs (>1000) into leaf buds (Heraty and Barber 1990;Heraty 2002), oviposition by Stilbuloida into the base of nectary-fi lled trumpet-shaped fl owers of Loranthus (Heraty 2002, unpublished), to a variety of behaviors in Stilbula such as oviposition of large masses (>10,000 eggs) into leaf buds or small masses on the side of wind-dispersed achenes (Clausen 1940).In all cases, there is either a direct association with fruit (apomorphic), an association of the eggs with ant-attractive fl ower nectaries, or with large egg-masses that resemble fruit and potentially attract the host ants (Heraty and Barber 1990).Th ese are considered as apomorphic behaviors for the entire Stilbula clade, but plesiomorphic to fruit oviposition, and all involve an association with recruitment behavior and the frugivorous habits of camponotine ants (Heraty and Barber 1990).
Antennal morphology across the Stilbula clade is highly diverse.Th e plesiomorphic condition, as based on comparison with the other subfamilies of Eucharitidae (Gollumiellinae and Oraseminae) as well as within Eucharitinae (Psilocharitini), is a simple cylindrical fl agellum (Heraty 2002).Pseudometagea all have a simple 8-10 segmented fl agellum and have been proposed as the sister group of the remaining Eucharitini (Heraty et al. 2004;Fig. 23).Within the Stilbula clade, Obeza, Stilbula, Stilbuloida and Substilbula have simple or at most lobate fl agellomeres in both sexes (Fig. 23c,i,j).Stilbuloida doddi is the only species with intraspecifi c variation in the antennae of females, ranging from simple to lobate (Fig. 23h).Basal fl agellomeres of females that are either slightly or strongly lobate (Figs 10,12,16) are considered plesiomorphic, whereas a basally or completely ramose fl agellum (Figs 6, 14, 23g) is apomorphic.Th e current hypothesis (Fig. 23) would suggest that long rami on the fl agellomeres of females (red line) is derived independently in the Asian species of Rhipipalloidea and in the prolata group of Pseudochalcura.Ramose male antennae have developed independently at least three times in the Stilbula clade (blue lines, Fig. 23).A dorsal ramus on at least the basal fl agellomeres is found in males of Rhipipalloidea, Pseudochalcura, Stilbuloida and Lophyrocera.In Leurocharis, the female has a simple fl agellum and the male has a dorsally strongly lobate fl agellum (Fig. 23b).Striostilbula females have simple fl agellomeres, whereas males have relatively short basal fl agellomeres similar to Stilbuloida (Heraty 2002).Females always have the projections oriented medially along the midline, as do males of Leurocharis, Stilbuloidea, Striostilbula and some Pseudochalcura.Th e dorsal origin of rami in males of Lophyrocera, Rhipipalloidea and some Pseudochalcura alternate along the dorsolateral and dorsomedial surfaces of each fl agellomere.Dorsal rami with linear or alternating dorsal origins have arisen independently in males of the Eucharis (uncommonly), Chalcura (commonly), and Kapala (all species) clades, but always with the rami along all segments, and never in females.
Only Pseudochalcura and Rhipipalloidea have developed ramose antennae in females.While ramose antennae in males are common, they have developed independ-ently in diff erent groups of Eucharitini, and often in diff erent forms.Across Eucharitini, there are similar diff erences in the origin of the rami, either medial or off set from the midline in males.Th e latter may be interpreted as a way of increasing the surface area for detecting pheromones.However it is not so easy to postulate why females would develop elongate rami.Th e question which remains is whether this is a pleiotropic eff ect linked to male antennal development, or a unique origin related to fi nding the accurate host plant for oviposition?Th e biology of both Rhipipalloidea and the prolata group of Pseudochalcura is unknown, and only further natural history insights from the fi eld will likely help to resolve these issues.
Th ere is strong support from both morphological and molecular data for a parallel split in both group A and B between the New World and Old World genera.In group A, there is a grade between the strictly Australian genera (Leurocharis and Substilbula), the Australasian Rhipipalloidea, and the New World Pseudochalcura.Rhipipalloidea extends north to the Philippines, whereas Pseudochalcura occurs as far north as Alaska and the Yukon (Heraty 1986(Heraty , 2002)).Th e chances for a recent exchange across a Beringian land connection appear likely.In group B, there is a split between the Australian Stilbuloida and the widespread Old World genus Stilbula, with the latter having an extensive northern distribution in Japan and western Russia (Heraty 2002).Lophyrocera and Obeza are restricted to the New World, with Obeza found only in subtropical areas of North America, but with Lophyrocera occurring as far north as the state of Washington in western North America.Again a recent faunal exchange seems likely.Based on molecular data, Carmichael (2003) predicted an age of divergence for the Stilbula clade ranging between 20-25 million years ago.Th is would fi t well with a late Miocene or later dispersal event of these diff erent groups within the Stilbula clade across the northern hemisphere (Davis et al. 2002;Renner et al. 2004).

Table 1
List of taxa, with DNA voucher codes (p = primary; s = secondary), collection localities, UCR museum specimen identifi ers (na = no voucher), and Genbank accession numbers.