Trichacis depressa 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: 17-19

publication ID 10.5281/zenodo.281325

persistent identifier

treatment provided by


scientific name

Trichacis depressa Arias-Penna & Masner

new species

Trichacis depressa Arias-Penna & Masner  , new species

Figures 7View FIGURE 7 E, 7 F; 8 A, 8 B

Female. Body length: 2.40 mm (holotype); 1.90–2.70 mm (paratypes, n= 4); mean length ± SD = 2.22 ± 0.33 mm. Black; A 1 –A 10 dark brown; mandible yellow with apex brown; fore leg yellow; mid leg with trochanter, femur and base of tibia yellow, otherwise brown; hind leg dark brown; mid coxa yellow; hind coxa brown; fore wing infuscate.

Head, in dorsal view, 2.1 times wider than long; EH> IOS; interocellar area with fine coriaceous sculpture; OOL > LOL; antennal clava 3 -segmented; A 1 distinctly surpassing vertex dorsal margin; A 2 –A 10 longer than wide; base of mandible smooth; frons between external margin of torulus and inner margin of eye medially covered by delicate coriaceous sculpture; interantennal process truncate, smooth and reaching, but not surpassing, ventral border of torulus; clypeus exposed; clypeal margin truncate; gena smooth; vertex laterally coriaceous and medially smooth; temple projection absent; hyperoccipital carina incomplete: in dorsal view, hyperoccipital carina fading before reaching level of imaginary line connecting eye inner margin to posterior cephalic margin; distance between posterior ocellus and hyperoccipital carina shorter than posterior ocellus diameter.

Mesosoma slightly arched; antero-admedian line present; notaulus anteriorly incomplete; lateral notaular area with coriaceous sculpture along its anterior margin; inter-notaular area with anterior 1 / 3 coriaceous and smooth in its posterior 2 / 3; posteromedial region of inter-notaular area broadly convex; parapsidal line present; central pronotal area smooth; specialized area of mesoscutellum heart-shaped, moderately elevated, with a rather broad tuft of hairs; mesopleural carina incomplete (length of mesopleural carina/length of mesopleuron = 0.12); fore wing not surpassing apex of metasoma.

Metasoma distinctly elongate and depressed dorsoventrally; combined length of T 3 –T 6> T 2; T 1 –T 2 longer than wide; T 3 –T 6 wider than long; anteromedial area of T 2 smooth and flattened; T 3 –T 5 with some parts smooth and densely covered by shallow punctuation; T 6 densely covered by shallow punctuation along its anterior margin and rest smooth; T 6 subtriangular.

Male. Unknown.

Etymology. The name of the species refers to its depressed metasoma.

Diagnosis. Trichacis depressa  and T. acarinata  have combined length of T 3 –T 6> T 2. T. depressa  is hitherto the only Neotropical species with a depressed metasoma and with EH> IOS.

Material examined. Holotype: 1 Ƥ, COSTA RICA, San José, Cerro de la Muerte, 19 km S, 3 km W Empalme, 2600 m, April –July 1992, MT, P. Hanson ( CNCI); paratypes: 3 Ƥ, with same data as holotype, (2 at CNCI and 1 at ICN); 1 Ƥ S.J. Cerro de la Muerte. November 1992, 2600 m, MT, P. Hanson ( CNCI).

Holotype is deposited in CNCI.


Institute of Oceanographic Sciences


Canadian National Collection Insects


Instituto de Ciencias Naturales, Museo de Historia Natural