Trichacis dianae 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: 19-21

publication ID 10.5281/zenodo.281325

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scientific name

Trichacis dianae Arias-Penna & Masner

new species

Trichacis dianae Arias-Penna & Masner  , new species

Figures 8View FIGURE 8 C – 8 F; 9 A

Female. Body length: 1.90 mm (holotype); 1.50–2 mm (paratypes, n= 20); mean length ± SD = 1.83 ± 0.13 mm.

Black; A 1 –A 5 yellow; A 6 –A 10 brown; mandible yellow with apex brown; fore and mid legs yellow; hind leg brown but with apices of femur and tibia darker; coxae dark brown; fore wing infuscate.

Head, in dorsal view, 2.7 times as wide as long; EH < IOS; interocellar area with fine coriaceous sculpture; OOL <LOL; antennal clava 4 -segmented; A 1 not reaching vertex dorsal margin; A 2 –A 3, A 5, A 10 longer than wide; A 4, A 6 –A 7 as long as wide; A 8 –A 9 wider than long; base of mandible smooth; frons above torulus and interantennal process with delicate transverse striae and coriaceous sculpture; interantennal process striate and surpassing ventral border of torulus; clypeus exposed; clypeal margin convex medially; gena striate; lateral area of vertex weakly coriaceous between posterior ocellus and hyperoccipital carina and with well-marked longitudinal striae between hyperoccipital carina and occipital carina; temple projection absent; hyperoccipital carina almost complete: 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 equal or slightly 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 coriaceous in its basal 1 / 3 and smooth in its posterior 2 / 3; posteromedial region of inter-notaular area convex; parapsidial line present; central pronotal area smooth; specialized area of mesoscutellum heart-shaped, median projection of specialized area of mesoscutellum triangular; mesopleural carina complete; 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; T 3 –T 6 wider than long; anteromedial area of T 2 smooth and concave; anterior pit of T 2 with longitudinal striae; T 3 smooth along its anterior margin and densely covered by shallow punctuation; T 4 –T 6 densely covered by deep punctuation; T 6 subtriangular.

Male. Body length: 2 mm (allotype); 1.70–1.85 mm (paratypes, n= 4); mean length ± SD = 1.82 ± 0.12 mm. Similar to female except the following: antenna filiform and yellow; A 2 wider than long; A 4, A 6 –A 10 longer than wide; T 1 as wide as long; T 3 –T 7 densely covered by deep punctuation.

Etymology. The species is named in honor of the entomologist Diana Carolina Arias-Penna. 

Diagnosis. Trichacis dianae  and T. procera  have complete mesopleural carina. T. dianae  differs by the combination of the following characters: OOL <LOL; presence of longitudinal striae on vertex; anterior pit of T 2 with longitudinal striae; smooth and concave T 2 anteromedial area.

Material examined. Holotype: 1 Ƥ, VENEZUELA, Lara, Yacambu, N. P., 1200 m, May 10 1981, H. Townes ( CNCI); allotype: 1 3, with same data as holotype but caught May 7 1981 ( CNCI); paratypes: COLOMBIA: 1 3, Magdalena, 11 º 10 ´N 74 º 8 ´W, 800 m, April 26–30 1973, J. Helava ( CNCI); ECUADOR: 1 Ƥ, Sucumbios, Sacha Lodge, 0º 30 ´S 76 º 30 ´W, 270 m, August 16–23 1994, MT, P. Hibbs ( CNCI); 1 Ƥ, Sucumbios, Río Napo, Sacha Lodge, 0º 30 ´S 76 º 30 ´W, 270 m, July 25 –August 3 1994, MT, Peter Hibbs ( CNCI); 1 Ƥ, Napo, Limoncocha, 250 m, June 15–28 1976, S. & J. Peck ( CNCI); VENEZUELA: 2 3, 3 Ƥ with the same data as allotype ( CNCI); 1 3, 6 Ƥ, with same data as holotype ( CNCI); 4 Ƥ, with same data as holotype but caught May 13 1981 ( CNCI), 2 Ƥ

Merida, Merida –Sta. Rosa, ca. 1800 m, May 11 1981. L. Masner ( CNCI); 1 Ƥ, Zulia El Tucuco, 200 m, Primary rain for., April 1981, L. Masner ( CNCI); 1 Ƥ, Aragua, Parque Nac. H. Pittier, Rancho Grande env., 1100 m, April 10–14 1994, YPT, L. Masner ( ICN).

Holotype is deposited in CNCI.


Institute of Oceanographic Sciences


Canadian National Collection Insects


Instituto de Ciencias Naturales, Museo de Historia Natural