Platyscelio Kieffer

Taekul, Charuwat, Johnson, Norman F., Masner, Lubomir, Polaszek, Andrew & Rajmohana K.,, 2010, World species of the genus Platyscelio Kieffer (Hymenoptera: Platygastridae), ZooKeys 50, pp. 97-126 : 99-102

Platyscelio Kieffer

Platyscelio Kieffer 1905:11 Original description. Type: Platyscelio pulchricornis Kieffer, by monotypy. Brues 1908: 27, 40 (diagnosis, list of species, keyed); Kieffer 1908: 113 (keyed); Kieffer 1910: 62, 66 (description, list of species, keyed); Dodd 1913: 130 (keyed); Kieffer 1913: 222 (description); Brues 1922: 21 (diagnosis, figure); Kieffer 1926: 265, 553 (description, keyed, key to species); Mani 1941: 29 (catalog of species of India); Muesebeck and Walkley 1956: 386 (citation of type species); Baltazar 1966: 186 (catalog of species of the Philippines); Masner 1976: 10, 55 (description, keyed); Mani and Sharma 1982: 190 (description); Galloway and Austin 1984: 9, 75 (diagnosis, keyed); Johnson 1992: 461 (catalog of world species); Austin and Field 1997: 34, 68 (structure of ovipositor system, discussion of phylogenetic relationships); Lê 2000: 31 (keyed); Rajmohana K. 2006: 117, 128 (description, keyed); Kononova and Kozlov 2008: 25, 319 (description, keyed).

Diagnosis.

Platyscelio is distinguished from most other genera of Scelioninae sensu Masner (1976) by the strongly dorsoventrally depressed, flat, and foliaceous body. A small number of other groups, such as Aradophagus Ashmead and Synoditella Muesebeck, are also more or less strongly depressed. Platyscelio may be distinguished from them by the absence of a netrion; the mandibles are tridentate, with the middle tooth small; the postmarginal vein is very short or absent, clearly shorter than the stigmal vein; and vein R in the hind wing is complete, extending to the hamuli on the costal margin of the wing.

Description.

Moderate-sized, length 3.0-5.6 mm; head prognathous, flattened anteroposteriorly, mesosoma and metasoma strongly dorsoventrally depressed; body black; macropterous.

Head:

Head in dorsal view strongly transverse; vertex laterad of posterior ocellus smooth or with few faint striae, between posterior ocelli finely longitudinally striate; hyperoccipital carina present as fine ridge on vertex between compound eyes; occipital carina absent; posterior ocellus distinctly separated from inner orbit of compound eyes, OOL> diameter of ocellus; compound eye large, appearing glabrous; frons without depression, shallowly convex, with median longitudinal sulcus bifurcating dorsally near median ocellus and ventrally near toruli; interantennal process well-developed, narrow; torular triangle present; submedian carina sometimes present; orbital carina sometimes present; lower frons, including cheek, with weak fanlike striae arising from mandibular condyle; shortest distance on frons between eyes less than eye height; inner orbits weakly diverging ventrally; postclypeus strongly projecting above anteclypeus, subtriangular, anteclypeus short, longest medially, lateral corners not produced; malar sulcus present; gena variably expanded, smooth to longitudinally striate or with few faint striae; labrum hidden by clypeus; mandible short, apex tridentate, middle tooth distinctly shortest, teeth arranged transversely; maxillary palpus 2-segmented, all segments cylindrical; labial palpus 1-segmented, very short; antenna 12-merous in both sexes; radicle very broad, inserted into ventral apex of A1, nearly parallel to longitudinal axis of A1, with small lateral spine; A1 almost triangular and expanded outwardly into spine, particularly in female; A2 distinctly shorter than A3; gustatory sensilla on female antenna arranged in longitudinal pairs on apical antennomeres; clava laterally compressed, claval formula A12-A8: 1-2-2-2-1; male antenna with tyloid on A5.

Mesosoma:

Mesosoma in dorsal view longer than wide, in lateral view much longer than high; pronotum in dorsal view strongly narrowed laterally, anterolateral corner weakly angulate; transverse pronotal carina absent; vertical epomial carina absent; dorsal epomial carina absent; lateral face of pronotum concave; netrion absent; anterior margin of mesoscutum strongly flexed ventrally to meet pronotum; mesoscutum semicircular in outline, posterolateral corner rounded; parapsidal line variably developed; notaulus variably developed: absent, nearly percurrent or percurrent, mesoscutum sometimes with strong sublateral carina paralleling notaulus; skaphion absent; prespecular sulcus and posterior mesepimeral sulcus present; speculum smooth, rarely longitudinally striate ( Platyscelio arcuatus ) transscutal articulation well developed; mesoscutellum rectangular in outline, truncate posteriorly, sculpture smooth to longitudinally striate; axilla small; posterior scutellar sulcus interrupted medially or complete; metanotum narrow, metascutellum clearly differentiated, size of metascutellum variable; dorsal surface of propodeum variable, weakly setose posteriorly; median propodeal sulcus present; plicae well developed; propodeal projections reduced; sternaulus absent; metapleural pit reduced; metapleural sulcus present dividing metapleuron into dorsal and ventral areas; setation of posterior half of ventral metapleural area variable; legs elongate; posterior surface of hind coxa smooth, glabrous to densely setose; trochantellus present; tibial spur formula 1-1-1; tarsal formula 5-5-5; tarsomeres cylindrical, broadening apically; pretarsal claw simple; apex of fore wing extending to or slightly beyond apex of S5 in female and S6 in male, hyaline or infuscate; R straight, extending slightly beyond basal half of length of wing, without strong, elongate bristles, gradually approaching costal margin apically, contiguous with costal margin for distance clearly exceeding length of r-rs (i.e., marginal vein elongate); r-rs straight; R1 usually absent, reduced, stumplike in some species ( Platyscelio arcuatus and Platyscelio mzantsi ) (i.e., postmarginal vein absent); bulla absent; Rs+M (basal vein) weakly to clearly indicated, nebulous; hind wing with R extending from base of wing to hamuli; three hamuli present.

Metasoma:

Metasoma elongate, parallel-sided, strongly flattened dorsoventrally; female with six visible terga and sterna, male with seven visible terga and sterna; second to fifth segments equal in length, third and fourth widest, subequal to each other in size; submarginal ridge developed, defined by narrow laterotergites to form deep submarginal rim; sublateral carina well developed on tergites, rarely absent ( Platyscelio striga ); no spiracles visible; sculpture on T1-T4 variable; S1 not laterally compressed; felt field absent.

Link to distribution map.

27 The genus Platyscelio is a widespread group throughout the Old World tropics, extending from West Africa to Queensland. Four species have relatively restricted distributions: Platyscelio arcuatus and Platyscelio striga (Western Australia), Platyscelio mysterium (Zimbabwe, Botswana, South Africa), and Platyscelio mzantsi (South Africa). Two species are widespread: Platyscelio africanus occurs in the Afrotropical realm from Senegal east to Yemen and south to South Africa; and Platyscelio pulchricornis is found in India and Southeast Asia east to Papua New Guinea and eastern Australia.

Key to species of Platyscelio