Trichacis acuta 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: 8-9

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Trichacis acuta Arias-Penna & Masner

new species

Trichacis acuta Arias-Penna & Masner  , new species

Figures 2View FIGURE 2 D– 2 F; 3 A– 3 D; 21 C

Female. Body length: 2.50 mm (holotype); 1.80–2.40 mm (paratypes, n= 7); mean length ± SD = 2.18 ± 0.24 mm. Black; base of A 1 yellow, distal part of A 1 and A 2 –A 10 dark brown; mandible yellow but apex brown and base dark brown; leg dark brown; fore wing infuscate in posterior 2 / 3, with darker and lighter patterns in basal 1 / 3.

Head, in dorsal view, two times as wide as long; EH < IOSAbout IOS; interocellar area coriaceous; OOL > LOL; antennal clava 4 -segmented; A 1 not reaching vertex dorsal margin; A 2 –A 6, A 10 longer than wide; A 7 as long as wide; A 8 –A 9 wider than long; base of mandible smooth; frons above torulus with 7–8 weak transverse striae; interantennal process smooth and reaching, but not surpassing, ventral border of torulus; clypeus exposed; clypeal margin convex medially; gena striate; vertex laterally coriaceous and medially smooth; temple projection present; hyperoccipital carina incomplete: in dorsal view, hyperoccipital carina fading until reaching level of imaginary line connecting eye inner margin to posterior cephalic margin; distance between posterior ocellus and hyperoccipital carina longer 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 anterior 1 / 3 coriaceous, otherwise smooth; posteromedial region of inter-notaular area convex; parapsidal line present; 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 = 0.55); fore wing distinctly surpassing apex of metasoma.

Metasoma elongate; combined length of T 3 –T 6 <T 2; T 1 as wide as long, T 2 longer than wide, anteromedial area of T 2 smooth and flattened; T 3 –T 6 shallowly covered by dense punctuation; T 6 triangular.

Male. Body length: 1.90 mm (allotype); 1.80 mm (paratypes, n= 2); mean length ± SD = 1.83 ± 0.06 mm. Similar to female except the following: antenna filiform; A 1 –A 10 dark brown; A 1 distinctly surpassing vertex margin; A 5 as long as wide; A 8 –A 9 longer than wide; T 1 shorter than wide; T 2 longer than wide; T 7 shallowly covered by dense punctuation; T 6 wider than long.

Etymology. The name of the species refers to the temple projection.

Diagnosis. Both Trichacis acuminata  and T. acuta  have temple projection but sculpture on the medial area of vertex is covered by striae in T. acuminata  and smooth in T. acuta  , and the shape of the anteromedial part of T 2 is concave in T. acuminata  and flat in T. acuta  . The Neartic species Trichacis bison  , T. cornuta  , and T. dracula  also have temple projection ( Masner 1983).

Material examined. Holotype: 1 Ƥ, COLOMBIA, Chuza, June 18 1992, MT, E. Palacio ( CNCIAbout CNCI); allotype: 1 3 with same data as holotype but caught July 27 1992 ( CNCIAbout CNCI); paratypes: 5 Ƥ, with same data as allotype (4 at CNCIAbout CNCI and 1 at ICNAbout ICN); 2 Ƥ, with same data as holotype ( CNCIAbout CNCI); 1 3 with same data as holotype ( ICNAbout ICN); 1 3, with same data as allotype ( CNCIAbout CNCI).

Holotype is deposited in CNCIAbout CNCI.


Institute of Oceanographic Sciences


Canadian National Collection Insects


Instituto de Ciencias Naturales, Museo de Historia Natural