Trichacis mexicana 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: 28-30

publication ID 10.5281/zenodo.281325

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scientific name

Trichacis mexicana Arias-Penna & Masner

new species

Trichacis mexicana Arias-Penna & Masner  , new species

Figures 13View FIGURE 13 A – 13 F

Female. Body length: 1.70 mm (holotype); 1.60 mm (paratypes, n= 2); mean length ± SD = 1.63 ± 0.06 mm.

Black; A 1 –A 5 yellow; A 6 –A 10 brown; mandible brown with base black; leg yellow; fore wing infuscate.

Head, in dorsal view, 2.5 times as wide as long; EH = IOS; interocellar area with faint, transverse, slightly curved striae; OOL > LOL; antennal clava 4 -segmented; A 1 not reaching vertex dorsal margin; A 2 –A 4, A 10 longer than wide; A 5 –A 6, A 9 as long as wide; A 7 –A 8 wider than long; base of mandible smooth; frons above interantennal process and torulus with four well marked transverse striae; interantennal process striate and reaching, but not surpassing, ventral border of torulus; clypeus exposed; clypeal margin truncate; gena striate; vertex laterally coriaceous and medially smooth; temple projection absent; hyperoccipital carina incomplete: in dorsal view, hyperoccipital carina surpassing 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 but weakly marked; notaulus anteriorly incomplete; lateral notaular area with coriaceous sculpture along its anterior margin; inter-notaular area in its basal 1 / 3 coriaceous and smooth in its posterior 2 / 3; posteromedial region of inter-notaular area convex; parapsidal line absent; central pronotal area smooth; specialized area of mesoscutellum heart-shaped; median projection of specialized area of mesoscutellum subtriangular; mesopleural carina incomplete (length of mesopleural carina/ length of mesopleuron = 0.23); fore wing distinctly surpassing apex of metasoma.

Metasoma moderately elongate; combined length of T 3 –T 6 <T 2; T 1 shorter than wide; T 2 longer than wide; T 3 –T 5 wider than long; anteromedial area of T 2 smooth and flattened; T 3 –T 6 densely covered by deep punctuation; T 6 subtriangular.

Male. Body length: 2 mm (allotype).

Similar to female except the following: antenna filiform; A 1 –A 10 yellow; fore and mid legs including coxae yellow; hind leg yellow except apices of femur and tibia brown; hind coxa brown; A 5 –A 9 longer than wide; T 1 shorter than wide, T 3 –T 5 smooth along its posterior margin and T 6 –T 7 densely covered by deep punctuation.

Etymology. Named after the country of the type locality.

Diagnosis. Trichacis mexicana  and T. panamana  shared the following characters: T 1 shorter than wide; clypeus exposed, and clypeal margin truncate. However, T. mexicana  has EH = IOS; OOL > LOL and distance between posterior ocellus and hyperoccipital carina shorter than posterior ocellus diameter. Color of antennal segment may vary, for instance holotype has A 6 –A 10 brown and paratype has A 7 –A 10 brown.

Material examined. Holotype: 1 Ƥ, MEXICO. Tamps, Río Frío nr. Gomez Farias, June 6 1983, UV, S. Peck & M. Kaulbars ( CNCI); allotype: 1 3 with the same data as holotype ( CNCI); paratypes: 1 Ƥ, Tamaulipas 18 m SE Manuel nr. Microondas sta., November 1 1982, SS, J. T. Huber & A. Gonzalez ( ICN); 1 Ƥ SLP, 1700 m, 40 km W Xilitla, June 12 –August 6 1983, S. Peck FIT ( CNCI).

Holotype is deposited in CNCI.


Institute of Oceanographic Sciences


Canadian National Collection Insects


Instituto de Ciencias Naturales, Museo de Historia Natural