Trissolcus vesta Kozlov & Le, 1893

Talamas, Elijah J., Buffington, Matthew L. & Hoelmer, Kim, 2017, Revision of Palearctic Trissolcus Ashmead (Hymenoptera, Scelionidae), Journal of Hymenoptera Research 56, pp. 3-185 : 69-71

Trissolcus vesta Kozlov & Le Figures 209-212

Trissolcus vesta Kozlov & Lê: Kozlov & Lê, 1977: 507 (keyed); Kozlov & Lê, 1977: 1253 (original description); Kozlov, 1978: 632 (description); Kozlov & Kononova, 1983: 97 (description); Kononova, 1995: 95 (keyed).

Description.

Female body length: 0.85-0.88 mm (n=2). Body color: head and mesosoma black, metasoma black to reddish brown.

Head. Color of radicle: yellow. Length of radicle: less than width of clypeus. Color of A1-A6 in female: brown. Color of A7-A11 in female: brown. Number of basiconic sensilla on A6: 0. Number of basiconic sensilla on A7: 2. Facial striae: absent. Number of clypeal setae: 6. Microsculpture on gena directly above mandibular condyle: absent. Shape of ventral gena in lateral view: narrow. Genal carina: absent. Malar striae: absent. Sculpture of malar sulcus: smooth. Macrosculpture of frons between antennal scrobe and anterior ocellus: absent. Preocellar pit: absent. Setation of lateral frons: sparse. Punctation of lateral frons: absent. Sculpture directly ventral to preocellar pit: microsculptured. Macrosculpture of lateral frons: absent. OOL: separated by less than one ocellar diameter. Hyperoccipital carina: absent. Macrosculpture of posterior vertex: absent. Microsculpture on posterior vertex along occipital carina: present. Anterior margin of occipital carina: finely crenulate to smooth.

Mesosoma. Netrion sulcus: complete. Pronotal suprahumeral sulcus in posterior half of pronotum: undifferentiated from sculpture of dorsal pronotum. Number of episternal foveae: 4 or more. Course of episternal foveae ventrally: abutting postacetabular sulcus. Course of episternal foveae dorsally: extending to mesopleural pit. Subacropleural sulcus: present. Speculum: transversely strigose. Mesopleural pit: simple. Mesopleural carina: complete. Sculpture of femoral depression: faintly rugulose. Patch of striae at posteroventral end of femoral depression: present, striae weakly developed and perpendicular to long axis of femoral depression. Setal patch at posteroventral end of femoral depression: present. Microsculpture of anteroventral mesopleuron: present dorsally. Macrosculpture of anteroventral mesopleuron: absent. Postacetabular sulcus: present as a smooth furrow. Mesopleural epicoxal sulcus: formed by small punctures; present as a smooth furrow. Setation of posteroventral metapleuron: present. Sculpture of dorsal metapleural area: absent; smooth posteriorly, cells of metapleural sulcus extending posteriorly into horizontal striae. Posterodorsal metapleural sulcus: poorly defined to absent. Paracoxal sulcus in ventral half of metapleuron: indistinguishable from sculpture to absent; absent. Anteroventral extension of metapleuron: extending to base of mesocoxa. Metapleural epicoxal sulcus: absent or indistinguishable from sculpture. Mesoscutal humeral sulcus: present as a simple furrow. Median mesoscutal carina: absent. Macrosculpture of mesoscutum: absent. Pattern of mesoscutal microsculpture: uniform throughout. Mesoscutal suprahumeral sulcus: absent. Parapsidal line: present. Notaulus: extending at least 1/3 length of mesoscutum. Median protuberance on anterior margin of mesoscutellum: present. Protruberance on anterior margin of mesoscutellum directly posterior to notaulus: present. Shape of dorsal margin of anterior lobe of axillar crescent: flat, appearing fused with lateral margin of mesoscutum. Sculpture of anterior lobe of axillar crescent: dorsoventrally strigose. Area bounded by axillar crescent: smooth. Macrosculpture of mesoscutellum: absent. Microsculpture on mesoscutellum: faintly present posteriorly. Median mesoscutellar carina: absent. Setation of posterior scutellar sulcus: present. Form of metascutellum: single row of cells. Metanotal trough: smooth in dorsal half, with line of foveae ventrally. Metapostnotum: invaginated near lateral edge of metascutellum. Length of postmarginal vein: about three times as long as stigmal vein. Color of legs: coxae and femora brown, elsewhere yellow. Anteromedial portion of metasomal depression: punctate or crenulate.

Metasoma. Longitudinal striae on T1 posterior to basal costae: present. Number of sublateral setae (on one side): 0. Setation of laterotergite 1: absent. Longitudinal striation of T2: present in anterior two-thirds of tergite. Setation of T2: present in a transverse line posteriorly. Setation of laterotergite 2: present. Striation of S2: absent. Setation of S2: sparsely present throughout area not covered by laterotergite.

Associations.

emerged from egg of Capnoda nigroaenea Jakovlev: [ Hemiptera: Heteroptera: Pentatomoidea: Pentatomidae ]

Material examined.

Holotype, female: RUSSIA: Altay Terr., Kurayskiy Mts., Kosh-Agach , 2400m, 22.VII.1964, Kozlov, ZMAS 0134 (deposited in ZIN) . Paratypes: RUSSIA: 2 females, USNMENT00916613, 00916648 ( ZIN) .

Diagnosis.

Trissolcus vesta is likely to be one of the more difficult species to identify due to the subtlety of some of its diagnostic characters, specifically the posterior vertex and the setation in the ventral metapleuron. In addition to metapleuron setation it has the suite of characters that delimit the thyantae group: notauli, 6 clypeal setae, and well defined episternal foveae that extend from the mesopleural pit to the dorsal limit of the acetabular carina. In T. vesta the posterior vertex is medially depressed, creating a triangular area in dorsal view that serves as an important diagnostic character that was recognized by Kozlov (1978), but also one that is best interpreted in the context of other species. Of additional use are the mesoscutal humeral and suprahumeral sulci, which are comprised of smooth furrows or very small and irregular cells, contrasting the large cells found in the most similar Palearctic species, T. scutellaris .

Comments.

The key to species of Palearctic Trissolcus by Kozlov (1978) used microsculpture of the mesoscutellum as a diagnostic character for this species. Contrary to his key, we observed that the sculpture of the mesoscutellum is significantly different from that of the mesoscutum: the mesoscutum is distinctly coriacieous throughout and microsculpture can be seen only very faintly on the posterior portion of the mesoscutellum under high magnification.

Figures

Figures 209 - 212. Trissolcus vesta female paratype (USNMENT 00916613) 209 head, mesosoma, metasoma, lateral view 210 head, mesosoma, metasoma, dorsal view 211 head and mesosoma, anterodorsal view 212 mesosoma, dorsolateral view. Scale bars in millimeters.