Afrotropical Ophioninae (Hymenoptera, Ichneumonidae): an update of Gauld and Mitchell’s revision, including two new species and an interactive matrix identification key

Abstract The revision of the Afrotropical Ophioninae is updated, based on the examination of about 800–900 individuals in the South African and European museum collections. A robust interactive matrix key was built to provide quick and reliable identifications. The key is available online at http://www.waspweb.org. Two new species are described: Dicamptus maxipol sp. n. and Enicospilus gauldetmitchellorum sp. n. Numerous new distribution and biological records are provided, and noticeable morphological intra-specific variations are detailed. Enicospilus batus Gauld & Mitchell, syn. n. is considered as a junior synonym of Enicospilus luebberti (Enderlein).


Introduction
The subfamily Ophioninae is one of the two major subfamilies of Ichneumonidae that have been extensively revised in the Afrotropical region. The revision of the Ophioninae is mainly due to Gauld and Mitchell (1978) where they keyed and provided detailed descriptions for the nearly 200 species they treated in the collections of the major natural history museums housing African material. They could thus emphasise the high endemism of this fauna, 98% of these species are not reported from outside of Subsaharan Africa.
It is of note that very few amendments have been brought to their work since the revision was published, except three new species descriptions Rousse and Villemant 2012) and some phylogenetic rearrangements (Gauld 1980;Gauld 1985;Quicke et al. 2005). Meanwhile, several expeditions led by the Iziko South African Museum in southern and tropical Africa produced a large amount of new ophionine material available for investigation. Here we provide new taxonomic, biological and distribution data extracted from examination of this material. In addition to updating Gauld and Mitchell's revision, an improved key in a new matrix format is providedto simplify the identification of Ophioninae in the region.

Photographs
Specimens were point mounted on black, acid-free card for examination (using a Leica M205C stereomicroscope with LED light source), photography and long term preservation. Images were acquired using the Leica LAS 4.4 imaging system, which comprised a Leica® Z16 microscope with a Leica DFC450 Camera with 0.63× video objective attached. The imaging process, using an automated Z-stepper, was managed using the Leica Application Suite V 4.4 software installed on a desktop computer. Lighting was achieved using techniques summarized in Buffington et al. (2005), Kerr et al. (2008) and Buffington and Gates (2009). All images presented in this paper are available at http://www.waspweb.org.

Terminology and abbreviations
The terminology follows Gauld and Mitchell (1978), but we preferred to use here the terms mesosoma and metasoma rather than alitrunk and gaster. Most morphological terms are also defined on HymaToL and HAO websites. The following morphometric abbreviations are used: B: body length, from torulus base to apex of metasoma (mm). F: fore wing length, from tegula base to wing apex (mm). ML (malar line index): shortest distance between eye and mandible / basal mandibular width. CT (clypeus transversality index): distance between outer edges of tentorial pits / median height of clypeus. POL (post-ocellar line index): shortest distance between posterior ocelli / posterior ocellus longest diameter. OOL (oculo-ocellar line index): shortest distance between eye and posterior ocellus / posterior ocellus longest diameter. FI (frontal index of head, Gauld and Mitchell 1978): maximum diameter of anterior ocellus / distance between eyes through maximum diameter of anterior ocellus.

Material examined and key development
Nearly 500 individuals were examined in the SAMC collections. We examined 300-400 more housed in the BMNH, MRAC, and MNHN collections. An interactive matrix key was developed for their quick and reliable identification. This key was initially produced based on the data extracted from Gauld and Mitchell's revision, and thereafter tested with the examined material. Uncertain identifications were cross-checked with Gauld and Mitchell's key and descriptions, and the matrix key was then amended to fit the unreported variability. Each species was coded somewhat loosely to limit the risk of false negative results when selecting limital states of characters. Specific attention was paid to species described on a reduced number of individuals to deal with the subsequent reduced range of known variability.

Results
Taking into account the taxonomic updates post Gauld and Mitchell's revision, including the present one, we acknowledge here a total of 194 species of Ophioninae in the Afrotropical region oncluding Skiapus coalescens Morley 1917 which is now included in Ophioninae (Quicke et al. 2005). A few individuals could not be definitively attributed to a given species, but only two individuals are unambiguously new species, which are described below. We also provide a list of new distribution or biological records. Some of these are not actually new because they are mentioned in Gauld and Mitchell (1978), but all of them are not yet reported in the Taxapad reference database (Yu et al. 2012). Finally, we provide a list of significant morphological intra-specific variation, with one in particular leading us to consider Enicospilus batus Gauld & Mitchell, syn. n. as a junior synonym of E. luebberti (Enderlein).

Identification keys
The matrix includes these 194 species and their known intra-specific variability. Furthermore, the dichotomous key provided in Gauld and Mitchell (1978) has been digitized and updated. Both keys are available at http://www.waspweb.org. Diagnosis. Orange with inter-ocellar area, most of mesosoma and apex of metasoma black; mandible not twisted, with a central tuft of hairs; clypeus wide, long and flat in profile; antenna short and stout with 56 flagellomeres; mesosoma laterally coarsely punctate to rugose-punctate, dorsally densely and more finely punctate; mesoscutum with notaulus distinct and relatively long; mesopleuron with epicnemial carina not distinct above lower corner of pronotum; propodeum anteriorly densely punctate, posteriorly coarsely rugose-reticulate; disco-submarginal cell with fenestra developed but without distinct sclerite; fore tibia with dense and long spines on outer surface; fore tibial spur with a vestigial basal membrane.

Dicamptus maxipol
Differential diagnosis. Differentiated from all other Dicamptus species in the world by the absence of distinct sclerites in the disco-submarginal cell; in the Afrotropical region, it seems related to D. neavei , which shares the dense spines on the tibia, the exceptionally reduced ocelli and a somewhat similar colour pattern; D. neavi is, however, a tropical species with shorter antennae, a stouter metasoma, and distinctly different alar indices with a distinct proximal sclerite in the disco-submarginal cell. In Gauld and Mitchell's key (1978), D. maxipol is included in the following modified first couplet: Color. Orange interspersed with black; black: inter-ocellar area, entire mesosoma except for mesonotum and metanotum, base of tergite 1, tergite 5 and following, all coxae and trochanters except trochantelli; antenna orange, slightly darkening toward apex; wings hyaline, venation dark reddish to black except for pterostigma anteriorly light reddish.
Head. Mandible short and stout, without longitudinal groove, with a central tuft of long hairs, upper tooth barely longer than lower tooth; malar line long; clypeus long and wide, coarsely and densely punctate, rather flat in profile, somewhat swollen medially and ventrally, ventral margin strongly impressed; face strongly transverse, densely and coarsely punctate; frons rather smooth, upper head densely punctate; gena moderately swollen behind eyes; occipital carina complete and strong; antenna short and stout with 56 flagellomeres.
Mesosoma. Pronotum, mesopleuron and metapleuron coarsely and densely punctate, fading to rugose-punctate ventrally; anterior margin of pronotum simple; epicnemial carina short, indistinct above lower corner of pronotum; posterior transverse carina of mesosternum complete though ventrally weak; submetapleural carina not expanded anteriorly; mesoscutum densely and more finely punctate; notaulus long, moderate, distinct to anterior third of mesoscutum; scutellum densely punctate, carinate almost to apex; propodeum with anterior area densely punctate, anterior transverse carina complete, posterior area coarsely rugose-reticulate, abruptly declivous in profile and mid-posteriorly concave. Wings. Disco-submarginal cell with fenestra developed, without any distinct sclerite except a weak quadra centrally; Rs+2r hardly sinuate, slightly bent and thickened near pterostigma; Rs&M distal to cu-a by about its own width; hind wing with 7 hamuli. Legs. Fore tibia with dense and long spines on outer surface; fore tibial spur with a vestigial membrane basally to macrotrichial comb, membrane barely less than 0.1× length of spur; hind coxa in profile 1.8× as long as high; hind trochantellus mid-dorsally 0.2× as long as wide; hind tarsal claws symmetrical with 8 pectinae.
MALE. Unknown. Etymology. Named after the unusually reduced ocelli, and as a result the large POL. Noun in apposition.
Distribution. South Africa (Western Cape).  Diagnosis. Yellow orange overall, head paler yellow; mandible with upper tooth distinctly longer than lower tooth; clypeus hardly convex in profile, its ventral margin barely concave and in-turned; occipital carinae complete; gena moderately swollen behind eye; ocelli moderately enlarged; antenna with 56 flagellomeres; pronotum unspecialized; mesopleuron and metapleuron closely and deeply punctate; epicnemial carina laterally indistinct; posterior transverse carina of mesosternum complete and noticeably strong; submetapleural carina slightly broadened anteriorly; notaulus vestigial; propodeum basally punctate, posteriorly coarsely and concentrically striate; fore wing without any sclerite in disco-submarginal cell; fore tibia with dense spines on outer surface; thyridium very shallow.

Enicospilus gauldetmitchellorum
Differential diagnosis. Readily differentiable from all other Enicospilus in Afrotropical, Oriental and Australasian regions by the combination of the absence of alar sclerites and the dense spines on fore tibia. The swollen genae and the wing venation make it somewhat related to E. leucocotis, but this latter is strongly larger, with only sparse spines on tibia and slenderer antenna. In Gauld and Mitchell's key (1978), E. gauldetmitchellorum is included in the following modified eighth couplet: 8 Fore tibia with dense and long spines, spines basally far closer than their own mean length; Tanzania  Description. FEMALE (holotype). B 18.8; F 11.5; ML 0.3; CT 1.6; OOL 0.1; POL 0.4; FI 50%; F 1-2 1.4; F 20 2.2; AI 0.6; CI 0.7; ICI 0.6; SDI 1.3; NI 2.8.
Color. Yellowish orange overall with face and orbits paler yellow and apex of metasoma slightly infuscate.
Head. Mandible basally constricted, apically parallel-sided and slightly twisted, with upper tooth distinctly longer than lower tooth (greatly worn by abrasion in holotype); outer mandibular surface sparsely setose, without longitudinal groove; labrum 0.3× as long as wide; clypeus in profile hardly convex, its ventral margin barely concave and in-turned; clypeus and face finely and moderately densely punctate; gena moderately swollen behind eye; occipital carina complete; ocelli slightly enlarged; antenna with 56 flagellomeres.
Mesosoma. Pronotum mid-dorsally long, anterior margin simple; mesoscutum densely punctate, notaulus vestigial; scuto-scutellar groove smooth; scutellum densely and shallowly punctate, barely longer than basally wide, carinate to near its apex; mesopleuron and metapleuron closely and deeply punctate, punctures arranged longitudinally but without distinct striation; epicnemial carina short, indistinct above lower corner of pronotum; submetapleural carina weakly broadened anteriorly; posterior transverse carina of mesosternum complete and strong; propodeum with anterior area finely, shallowly and densely punctate, anterior transverse carina complete, posterior area coarsely and concentrically striate Wings. Disco-submarginal cell with fenestra developed, without any distinct sclerite; Rs+2r sinuate; cu-a basal to Rs&M by 0.3× cu-a length; hind wing with 6 hamuli and 1A basally straight. Legs. Fore tibia with numerous dense and long spines on outer surface, basally separated by far less than their own length; hind coxa elongate, in profile 2.4× as long as high; hind trochantellus middorsally 0.2× as long as wide, its apical margin simple; hind tarsal claws symmetrical with 8 pectinae, pectinae long and acute.

MALE. Unknown.
Etymology. This species was probably mentioned in Gauld and Mitchell (1978) as an undescribed specimen close to E. leucocotis. Let give Gauld what belongs to Gauld (updated after Mark 12:17).

New distribution records
Provided are the verbatim label data. Only unambiguous identifications are listed. All geographical coordinates are also available on a separate file as Suppl. material 1.