Revision of the Neotropical species of Trichacis Foerster (Hymenoptera: Platygastroidea: Platygastridae), with description of 24 new species Author Arias-Penna, Tania Milena Author Masner, Lubomir Author Delsinne, Thibaut text Zootaxa 2012 3337 1 56 journal article 10.5281/zenodo.281325 706d7536-7046-48ee-a586-a7bd417b58eb 1175-5326 281325 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. FIGURE 19. Trichacis triangulata Arias-Penna & Masner , n. sp. , 3, habitus, lateral view (allotype). 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. FIGURE 20. Trichacis triangulata Arias-Penna & Masner , n. sp. A–C: 3 (allotype). A, head and anterior mesosoma, lateral view; B, metasoma, dorsal view; C, head, dorsal view. D–F: Ƥ (holotype). D, head and ventral mesosoma, anterior view; E, head and mesosoma, dorsolateral view; F, metasoma, dorsal view. 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 .