Trissolcus tersus 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 : 62

Trissolcus tersus Le Figures 189-190 , 191-193

Trissolcus tersus Lê, 1985: 166 (original description); Johnson, 1992: 638 (cataloged, type information); Lê, 2000: 312, 320 (description, keyed, type information).

Description.

Female body length: 0.99-0.81 mm (n=2). Body color: head, mesosoma, and metasoma black.

Head. Color of radicle: yellow. Length of radicle: less than width of clypeus. Color of A1-A6 in female: basal A1 and distal A2 yellow, elsewhere pale brown. Color of A7-A11 in female: dark brown. Number of basiconic sensilla on A6: 0. Number of basiconic sensilla on A7: 2. Facial striae: present as elongate striation. Number of clypeal setae: 6. Microsculpture on gena directly above mandibular condyle: present. Shape of ventral gena in lateral view: narrow. Genal carina: present only at base of mandible. Malar striae: present. Sculpture of malar sulcus: smooth. Orbital furrow: medially delimited by ridge or carina at midpoint of eye, poorly defined or absent near intersection with malar sulcus. Macrosculpture of frons between antennal scrobe and anterior ocellus: absent. Preocellar pit: absent. Setation of lateral frons: moderately dense. Punctation of lateral frons: absent. Sculpture directly ventral to preocellar pit: microsculptured. Macrosculpture of lateral frons: absent. OOL: lateral ocellus and eye without continuous scleritic separation. Hyperoccipital carina: complete. Anterior margin of occipital carina: simple.

Mesosoma. Epomial carina: absent. Macrosculpture of lateral pronotum directly anterior to netrion: finely rugulose. Netrion sulcus: complete. Pronotal suprahumeral sulcus in posterior half of pronotum: undifferentiated from sculpture of dorsal pronotum. Posterior pronotal sulcus: absent. Number of episternal foveae: 3. Course of episternal foveae ventrally: distinctly separate from postacetabular sulcus. Course of episternal foveae dorsally: extending to mesopleural pit. Subacropleural sulcus: present. Speculum: weakly transversely wrinkled. Mesopleural pit: simple. Mesopleural carina: complete. Sculpture of femoral depression: smooth. Patch of striae at posteroventral end of femoral depression: absent. Setal patch at posteroventral end of femoral depression: present. Microsculpture of anteroventral mesopleuron: present throughout. Macrosculpture of anteroventral mesopleuron: absent. Postacetabular sulcus: formed by large cells. Mesopleural epicoxal sulcus: formed by open crenulae. Setation of posteroventral metapleuron: present. Sculpture of dorsal metapleural area: smooth area large, surrounded by well defined sulci. Posterodorsal metapleural sulcus: present as line of foveae. Paracoxal sulcus in ventral half of metapleuron: indistinguishable from sculpture to 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: comprised of cells. Length of mesoscutal suprahumeral sulcus: about half the length of anterolateral edge of mesoscutum. Parapsidal line: absent. Notaulus: absent. Median protuberance on anterior margin of mesoscutellum: absent. Shape of dorsal margin of anterior lobe of axillar crescent: round. Sculpture of anterior lobe of axillar crescent: dorsoventrally strigose. Area bounded by axillar crescent: smooth. Macrosculpture of mesoscutellum: absent. Microsculpture on mesoscutellum: present throughout. Median mesoscutellar carina: absent. Setation of posterior scutellar sulcus: present. Form of metascutellum: single row of cells. Metanotal trough: foveate, foveae occupying more than half of metanotal height. Metapostnotum: invaginated near lateral edge of metascutellum. Length of postmarginal vein: about 1.5 times as long as stigmal vein. Color of legs: coxae dark brown, legs elsewhere yellow. Anteromedial portion of metasomal depression: smooth.

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: absent. Setation of T2: present in a transverse line posteriorly. Setation of laterotergite 2: absent.

Diagnosis.

Trissolcus tersus can be identified by the line of foveae along the dorsal margin of the mesopleural carina (Figures 189 , 192 ), a character known to us so only from this species. The setation of the posteroventral metapleuron (Figure 189 ) and the presence of facial and malar striae (Figure 193 ) are also useful for its identification.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=3318

Material examined.

Holotype, female: VIETNAM: Hoa Binh Prov., rice field, Thuong Tien , 11.XI.1978, IEBR 0043 (deposited in IEBR) . Other material: (9 females) INDONESIA: 1 female, CNC424618 ( CNCI). THAILAND : 7 females, CNC424502-424505, CNC424607, CNC424619 ( CNCI); EMBT ENT 0001839 ( USNM).

Figures

Figures 189 - 190. Trissolcus tersus female (EMBT ENT 0001839) 189 head, mesosoma, metasoma, lateral view 190 head, mesosoma, metasoma, dorsal view. Scale bars in millimeters.

Figures 191 - 193. Trissolcus tersus female (EMBT ENT 0001839) 191 head, mesosoma, anterodorsal view 192 head and mesosoma, ventrolateral view 193 head, anterior view. Scale bars in millimeters.