Scelio

Yoder, Matthew, Polaszek, Andrew, Masner, Lubomir, Johnson, Norman & Valerio, Alejandro, 2009, Revision of Scelio pulchripennis - group species (Hymenoptera, Platygastroidea, Platygastridae), ZooKeys 20 (20), pp. 53-118 : 57-61

Scelio , pulchripennis -group Nixon, 1958

Description. Predominantly moderately sized relative to other species of Scelio, Length 1.78–4.77mm; habitus somewhat flattened in lateral view, vertical distance between dorsal extent of mesonotum and propodeum minimal; body variously colored, orange to black, in some with metallic blue to green color on the head, mesosoma and posterodorsal metanotum; fore legs often lighter colored than mid and hind; sculpture often fine, or faintly impressed, often obliterated in patches; macropterous.

Pilosity throughout body of moderate length to elongate, often semi-erect to erect, in most with apices slightly curved, color typically lighter (white to light yellow) on lateral surfaces and on lateral T1–T2 and light golden brown on dorsal surfaces and apical metasoma; pilosity of lower (Fig. 2, lwf) and lateral frons (Fig. 2, laf) sparse to moderate, appressed to semi-decumbent, laterally oriented; pilosity of upper frons (Fig. 3, uf) sparse to moderate, appressed to semi-decumbent, orientation varying, though in nearly all species ventralmost setae laterally oriented, with those near the anterior ocellus and above dorsally oriented (see Comments section in species descriptions for notable exceptions); pilosity of the dorsal head (e.g. Fig. 4) nearly always similar in form and density to that of anterior, with few exceptions (see Comments sections in species descriptions); clypeus (anteclypeus) with three pairs of setae, the medial pair longest (Fig. 5); pilosity immediately adjacent to malar sulcus oriented posteriorly, sharply contrasting with ventrally oriented setae of posterior gena (lateral view); eye glabrous; pilosity of pronotum appressed to semi-decumbent, posterolaterally oriented; netrion always setose; pilosity of the anterior mesoscutum oriented posteriorly, that on the posterior mesoscutum oriented toward midline; pilosity of mesoscutellum frequently sparser medially, often slightly more erect than remaining mesonotal and mesoscutal setae, variously oriented; line of setae along anterior mesopleuron sparse (ventrally) to very dense; dorsal surface of propodeum almost glabrous, with only a small patch in anterolateral corner and a sparse line along posterolateral corner; line of setae along anterior line of metapleuron moderate to dense dorsally,

Figures 7–Ι2 .50 7 Scelio turbidus sp. n., hind femur, tibia, anterior view, female (OSUC 223095) 8 S. antorides Nixon , hind tibia, anterior oblique view, female (OSUC 214234) 9 S. baoli Risbec , anterior metasoma, dorsal view, female (OSUC 214182) Ι0 Scelio parapulchripennis sp. n., anterior metasoma, dorsal view, female (CASENT 2042134) ΙΙ Scelio paranitens sp. n., metasoma, lateral view (OSUC 211472) Ι2 Scelio parapulchripennis sp. n., posterior metasoma, dorsal view (CASENT 2042134). Abbreviations: ht, hind tibia; sam, subapical margin. Scale bars in millimeters.

absent to very dense ventrally; T1–T3 more or less glabrous dorsally, sometimes with line of sparse appressed setae along posterior margin of T3; dorsal T4–T6 gradually more densely setose, often with setae gradually more erect posteriorly; T1 laterally with sparse to moderately dense pilosity, line of setae on lateral margin absent to sparsely present, never forming dense linear patch; pilosity of lateral T2–T6 typically somewhat sparse though very dense in a few species, density and form largely following that of remaining body; laterotergites glabrous or with sparse, appressed to semidecumbent short, straight, and narrow light brown setae.

Head somewhat quadrate in anterior view, with gena below eye not strongly curved towards mandible ( Nixon 1958), and somewhat sharply reflexed towards mandible, narrow in lateral view; claval formula A12–A7:1-2-2-2-2-2; flagellum relatively compact, A3–A4 not particularly elongate, evenly broadening into base of compact clava; male flagellum compact, flagellomeres typically as wide or wider than long; male A5 unmodified; ocelli very small, lateral ocellus separated from margin of eye by a distance roughly equal to its diameter; ventral orbit of eye often with some minute rugulae; malar sulcus always present, sometimes partially obliterated; sculpture surrounding malar sulcus obliterated to absent, rarely with smoother area reduced to a thin strip, usually with some very fine confused rugulae along anteroventral margin of eye; antennal scrobe not developed, confluent with surrounding surface, nearly always with fine transverse striae, uncommonly with confused rugulae; interantennal process not strongly projecting, uniform in shape, without medial armature, toruli (carina of interantennal process) not forked or extended onto antennal scrobe; mandible with lower tooth reduced in size, often blunt and much shorter than upper tooth, rarely completely absent; upper mandibular node absent; basal tooth absent; lateral head smooth with setigerous punctures to more or less reticulate with margins smooth to obliterated, frequently finely umbilicate, density and distribution of sculpture closely paralleling that of remainder of head; genal carina absent; occipital carina percurrent, a sharp narrow carina, clearly concave (sometimes deeply so) near base of mandible.

Mesosoma with vertical epomia almost horizontal, never percurrent, obliterated anteriorly, typically present only as a slight branch from the junction of the transverse pronotal carina and the lateral epomial carina; antespiracular patch of pronotum present near posterior extension of lateral epomia, slightly anteroventral to pronotal spiracle, patch a verriculelike bump or small group of appressed to semierect setae; pronotal collar thin and smooth, without even microsculpture; anterior margin of netrion generally poorly delimited, somewhat fused throughout; fore wing typically surpassing anterior margin of T5, without percurrent tubular veins; venation in both sexes reduced, fore wing with submarginal vein more or less obliterated near its curve towards costal margin, never tubular; stigmal vein nebulous; fore wing pseudostigma present but poorly differentiated; hind wing submarginal vein spectral except at base where it is nebulous; female fore wing pictate, always with a basal pigmented spot, a basal fascia, and pigmentation in apex beyond pseudostigma, apical pigmentation typically beginning at stigmal vein, with or without an apical fascia, margin glabrous; male wings hyaline to (rarely) slightly infuscate; mesoscutellum broadly separated from mesoscutum medially; axillulae (lateral node) weakly developed; mesepipleural margin undefined; metascutellum unarmed; propodeum flat, prominently visible in dorsal view, with longitudinal-sinuate (serpentine) sculpture throughout (species with metallic color, e.g., Fig. 60), or sculpture predominantly reticulate (species without metallic color); propodeal projections not developed, corners of propodeum relatively evenly rounded, not bulging laterally (Fig. 60); propodeal nucha smooth, medially divided by extension of the medial carinae of propodeum, in larger individuals some weak additional longitudinal carinae laterad of medial carinae; upper margin of metapleuron posterior to propodeal spiracle strongly sloped, somewhat curved; metapleural depression more or less absent; legs without spines or other obvious armature; hind femur smooth, sparsely setose, with distinct lines of erect setae along antero- and dorsoventral margins.

Metasoma in lateral view with terga and sterna more or less symmetrical, weakly convex, or terga evenly arcuate (Fig. 11, most metallic individuals); anterior margin of T1 concave; sculpture of T4–T5 similar in form to that of T3, but typically denser, more compact, finer, less strongly impressed; T6 sculpture variable, degree of impression of sculpture similar to that seen in preceding terga, typically consisting of confused longitudinal striae that curve slightly towards posterolateral margin, number of reticulations variable, interstices more or less smooth to irregularly minutely rough; preapical margin of T6 always semicircular (Fig. 12, sam); sculpture on transition from dorsal to lateral terga often obliterated; felt fields absent, at most with extremely slight differentiation (narrow, as if pinched together) on T2; medial S3–S5, and sometimes S2, with sculpture obliterated to absent, rarely sculpture present; lateral S3–S 5 in most species with longitudinal sculpture, in a few this somewhat reticulate; S6 sculpture variable, often irregularly reticulate, with some longitudinal trend, interstices smooth to minutely rough, sculpture fine to coarse.

Diagnosis. Most similar to species in the walkeri group sensu Nixon (1958), both sharing the absence of angular corners of the propodeum, presence of a sharply cascading band of setae behind the propodeal spiracle (lateral view), and the absence of modification of the male A5. Distinguished from species of the walkeri group by the broadly concave clypeus with a slight medial projection, the absence of a basal tooth on the mandible, the strong reduction to absence of the lowermost (posterior/ventral) tooth, the absence of thickened appressed white setae and the relatively flattened habitus with elongate propodeum. Additional diagnostic (but not unique) characters include the presence of pictate wings in females, the evenly rounded, semicircular subapical margin of T6 (Fig. 12, sam), and the more or less completely sculptured lower frons. Around half the known pulchripennis -group species can be further distinguished from Old World species of Scelio by the presence of metallic coloration on the head, mesosoma or dorsal metasoma.

Two other groups warrant mention here. An undescribed group (“S”) known from three species from South Africa shares several similar characters. The anteclypeus shares the same general form but is narrower, with the medial point much broader. Species of group “S” also have somewhat narrow, erect pilosity as seen in many pulchripennis - group species, and relatively fine sculpture throughout. However, the setae are more robust (not flattened) than pulchripennis -group species and females do not have pictate fore wings. Scelio fulgidus Crawford , an Australian species, also shares a number of apparent convergences or parallelisms with species of the pulchripennis -group. Specimens of S. fulgidus have the lower mandibular tooth reduced, with the mandible relatively sharply pointed, a somewhat flattened habitus, and numerous obliterated or polished areas. Beyond these striking but superficial similarities they can be diagnosed against pulchripennis -group species by the lack of pictate wings, the shape of S6, and the trapezoidal medial anteclypeus.

Distribution. Species of the pulchripennis -group are found throughout Africa (including the Canary Islands), the southern Arabian Peninsula, Turkmenistan, India, Sri Lanka, Nepal and Mongolia.

Comments. Based on the available material, females are more commonly collected than males by a ratio of about 4:1. Males of the different species are quite uniform in sculpture, particularly that of the thorax, and have reduced metallic color in those species that have it. Based on external morphology alone, the association of males with conspecific females is difficult. The absence of modifications of the male release and spread structure (A5) and the interspecific convergence of sculptural characters of the mesonotum (in males) complicates this task. Because of the limited material available, males were not dissected, and diagnoses and descriptions pertain to females alone unless otherwise explicitly noted.