Trichacis triangulata Arias-Penna & Masner

Arias-Penna, Tania Milena, Masner, Lubomir & Delsinne, Thibaut, 2012, Revision of the Neotropical species of Trichacis Foerster (Hymenoptera: Platygastroidea: Platygastridae), with description of 24 new species, Zootaxa 3337, pp. 1-56 : 39-42

Trichacis triangulata Arias-Penna & Masner , new species

Figures 18 F–18H; 19; 20A–20F

Female. Body length: 2.05 mm (holotype); 1.95–2.20 mm (paratypes, n=3); mean length ± SD = 2.09 ± 0.11 mm. Black; A1–A10 brown; mandible black with apex brown; fore leg yellow; mid leg brown, with apical ½ of tibia darker; hind leg brown, with tarsi and apical ½ of femur and tibia darker; fore coxa brown; hind coxa dark brown, fore wing infuscate.

Head, in dorsal view, 2.6 times as wide as long; EH <IOS; interocellar area finely coriaceous; OOL> LOL; antennal clava 3-segmented; A1 not reaching vertex dorsal margin; A2–A4 and A10 longer than wide; A5–A6 as long as wide; A7–A9 wider than long; base of mandible smooth; frons above torulus and interantennal process coriaceous with three marked transverse striae; interantennal process surpassing ventral margin of torulus; clypeus exposed; clypeal margin convex medially; gena striate; vertex with lateral region coriaceous and with medial region smooth between posterior ocellus and hyperoccipital carina and coriaceous between hyperoccipital carina and occipital carina; temple projection absent; hyperoccipital carina complete; distance between posterior ocellus and hyperoccipital carina shorter than posterior ocellus diameter.

Mesosoma arched; antero-admedian line present; notaulus anteriorly incomplete; lateral notaular area with coriaceous sculpture along its anterior margin; inter-notaular area with basal 1/3 coriaceous and posterior 2/3 smooth; posteromedial region of inter-notaular area convex; parapsidal line present; central pronotal area with posterior half coriaceous; specialized area of mesoscutellum with broad triangular sheet-like projection, moderately elevated; mesopleural carina incomplete (length of mesopleural carina/length of mesopleuron = 0.29); fore wing distinctly surpassing apex of metasoma.

Metasoma elongate; combined length of T3–T6 <T2; T1 shorter than wide; T2 slightly longer than wide; anteromedial area of T2 smooth and flattened; T3 anterior margin smooth and with shallow punctuation; T4–T6 densely covered by deep punctuation; T6 subtriangular.

Male. Body length: 2.20 mm (allotype); 1.95–2.30 mm (paratypes, n=10); mean length ± SD = 2.09 ± 0.11 mm.

Similar to female except the following: head, in dorsal view, twice as wide as long; EH <IOS; antenna filiform; A5, A7–A9 longer than wide; T1–T2 longer than wide.

Etymology. The name of the species refers to the shape of its specialized area of the mesoscutellum.

Diagnosis. Trichacis triangulata is the only species to have the combination of the following characters: distance between posterior ocellus and hyperoccipital carina shorter than posterior ocellus diameter; T1 shorter than wide, and specialized area of mesoscutellum with broad triangular sheet-like projection.

Material examined. Holotype: 1 Ƥ, MEXICO, Oax, 26 km E Valle Nacional, 1220 m, June 25 1983, M. Kaulbars & S. Peck; allotype:1 3, with same data as holotype ( CNCI); paratypes: 9 3, 3 Ƥ, with same data as holotype ( CNCI), 1 3, with same data as holotype but collected by S. Peck ( ICN).

Holotype is deposited in CNCI.

Figures

FIGURE 18. Bright field images of Trichacis species. A: Trichacis sculpturata Arias-Penna & Masner, n. sp., Ƥ, head, dorsal view (holotype). B – E: Trichacis transversata Arias-Penna & Masner, n. sp., Ƥ (holotype). B, head, anterior view; C, habitus, dorsal view; D, habitus, lateral view; E, head and mesosoma, dorsolateral view. F – H: Trichacis triangulata Arias-Penna & Masner, n. sp., 3 (allotype). F, head and ventral mesosoma, anterior view; G, habitus, dorsal view; H, head and mesosoma, dorsal view.