Platygaster tricarinata, Buhl, 2014

Buhl, Peter Neerup, 2014, New species and new records of Platygastrinae and Sceliotrachelinae from Togo (Hymenoptera: Platygastridae), African Invertebrates 55 (1), pp. 68-68 : 102-104

Platygaster tricarinata sp. n.

Figs 63–65

Etymology: Derived from Latin tres (three) and carina (keel); in reference to the three, usually distinct, carinae on the base of T2.

Diagnosis: A rather small species with head fully 1.2× as wide as mesosoma, occiput finely striated over whole width, without a hyperoccipital carina; female as well as male A9 as wide as long; notauli absent or weak, only present in posterior half; mid lobe broadly and slightly projecting over base of scutellum, this being low and evenly sloping; propodeal carinae parallel; female metasoma 0.85× as long as rest of body; T2 striated to 0.45 of length, medially with three more or less distinct longitudinal carinae to almost 0.3× length of tergite; legs partly darkened.

Description:

Female.

Body length 0.7–1.0 mm. Black; A1–A2, mandibles and legs medium-dark brown with trochanters, most of fore tibiae, basal half of mid and hind tibiae, and segments 1–4 of all tarsi light brown; A3–A10 dark brown. Head from above ( Fig. 63 ) 2.05× as wide as long, fully 1.2× as wide as mesosoma; occiput finely but distinctly semi­circularly striated over whole width on a smooth background, slightly margined anteriorly but without a distinct carina; vertex laterally smooth, finely and transversely reticulate­striate between ocelli; frons smooth in most of upper half, rest with fine oblique striation, smoother towards middle, with transverse striation just above antennal insertions. OOL and LOL about equal. Head in frontal view 1.25× as wide as high.Antenna ( Fig. 65 ) with A1 0.8× as long as height of head, 0.95× as long as distance between inner orbits; A9 as wide as long. Mesosoma ( Figs 63 and 64 ) 1.3× as long as wide, 1.1× as high as wide. Sides of pronotum smooth, with sparse setation over most of surface. Mesoscutum rather sparsely and evenly setose, smooth except for weak microsculpture at anterior ends of notaulic courses; notauli weak, fading out in anterior half, sometimes entirely absent; mid lobe broad behind, slightly but distinctly prolonged over base of scutellum, at each side with about 4–7 long setae over scuto-scutellar grooves. Mesopleuron smooth. Scutellum more densely setose than mesoscutum, at level thereof, smooth, evenly sloping behind. Metapleuron with pilosity all over. Propodeal carinae short, parallel; much of the transverse area between them smooth. Fore wing 0.8× as long as entire body, 2.4× as long as wide, surpassing tip of metasoma by a distance equal to two­thirds of the length of T2, faintly yellowish, with fine and dense microtrichia; marginal cilia 0.07× width of wing. Hind wing 6.0× as long as wide, with two hamuli; marginal cilia 0.4× width of wing. Metasoma 0.85× as long as head and mesosoma combined, 0.85× as wide as mesosoma. T1 with five rather even longitudinal carinae on central area. T2 with two finely striated basal foveae reaching 0.45× length of tergite, between basal foveae with three longitudinal carinae to almost 0.3 length of tergite. T3–T6 smooth, each with a transverse row of setae inserted in shallow punctures (about six on each of T3–T4 and eight on each of T5–T6).

Male.

Body length 0.70–0.75 mm. A4 inconspicuously widened; A8–A9 each about as long as wide. Metasoma about 0.8× as long as head and mesosoma combined.

Comparison: Generally similar to P. lobata sp. n. (see above). The most important characters separating the two species are length of mid lobe over scutellum and conformation of propodeal carinae. P. tricarinata could run to two species in Buhl’s (2011 b) key. However, P. malaisei Buhl, 2005 , has a more transverse head, mid lobe of mesoscutum shorter, propodeal carinae slightly divergent, and female metasoma as long as rest of body. P. baezi Buhl, 2003 , has a more convex scutellum with shorter mid lobe (and a very different conformation of male antennae).

Holotype: ♀ TOGO: Région des Plateaux, Akloa, at creek Domi coming from the Cascades d’Akloa (07°30'46"N 00°36'36"E), 22.iv. 2008, 280 m, cocoa and avocado plantation, swept, M. von Tschirnhaus.

Paratypes: 3♀ 2♂ Région des Plateaux , N of Kessibo­Wawa, at the border to Ghana (N of Badou), at river Wawa (07°42'11"N 00°35'26"E), 24.iv. 2008, 180 m, forest understorey, cocoa plantation sun-exposed vegetable fields, some Cyperaceae , swept ; 1♀ Région des Plateaux , Plateau de Danyi, near Atigba (07°09'52"N 00°41'33"E), 14.iv. 2008, 775 m, remains of secondary rainforest, underwood, forest plantation, road side with much Sida acuta , swept ; 1♀ Région des Plateaux , Anonoè, at brook Okpabè (07°33'40"N 00°36'10"E), 22.iv. 2008, 280 m, swept along bank and in cocoa plantation. All M. von Tschirnhaus .

Figures

Figs 63, 64. Platygaster tricarinata sp. n., female head and mesosoma in (63) dorsal and (64) lateral view. Scale bars = 10 μm.

Fig. 65. Platygaster tricarinata sp. n., female antenna. Scale bar = 10 μm.