Alexeter flaviventris, Li & Sun, 2022

T., Li & S. P., Sun, 2022, The genus Alexeter Förster (Hymenoptera, Ichneumonidae) in China, with descriptions of three new species, European Journal of Taxonomy 789 (81), pp. 81-103 : 88-92

Alexeter flaviventris sp. nov.

urn:lsid:zoobank.org:act:0847F2E8-38C1-4305-97E3-6F4596DEB1B8

Figs 12–23

Diagnosis

Face ( Fig. 13 ) approximately 1.6× as wide as long. Malar space about 0.4× as long as basal width of mandible. Median portions of lateromedian longitudinal carinae combined ( Fig. 20 ), length of combined carina as long as area superomedia. First metasomal tergite ( Fig. 21 ) approximately 1.9 × as long as posterior width. Metasomal sternites ( Fig. 12 ) whitish yellow.

Differential diagnosis

The new species can be easily distinguished from other species of Alexeter by having the median portions of the lateromedian longitudinal carinae of the propodeum combined, the length of the combined carina as long as the area superomedia; metasomal sternites entirely whitish yellow.

Etymology

The specific name is derived from the whitish yellow metasomal sternites.

Material examined

Holotype CHINA • ♀; Guizhou Province, Weining, Tuoda Nature Reserve ; 2120 m a.s.l.; 20 May 2020; interception trap; GSFGPM.

Paratype CHINA • 1 ♀; Beijing, Yanqing, Songshan National Nature Reserve ; 18 Aug. 2020; interception trap; GSFGPM .

Description

Female

MEASUREMENTS. Body ( Fig. 12 ) length approximately 7.5 mm. Fore wing approximately 6.6 mm. Ovipositor sheath length approximately 0.5 mm.

HEAD. Inner margins of eyes slightly convergent ventrally. Face ( Fig. 13 ) approximately 1.6× as wide as long, almost flat, shagreened, upper margin with median V-shaped emargination. Clypeus with sculpture from face, smooth, shiny, approximately 2.9× as wide as long; with few, fine punctures and brown setae; subapical portion strongly convex; apical margin almost truncate. Mandible with sparse punctures and brown setae; lower tooth as long as upper tooth. Malar space shagreened, with dense yellowish brown setae, about 0.4× as long as basal width of mandible. Gena ( Fig. 15 ) finely shagreened, evenly convergent backward. Vertex ( Fig. 14 ) with sculpture as gena. Postocellar line approximately 0.9 × as long as ocular-ocellar line. Frons slightly concave above antennal socket, shagreened. Antenna with 37 flagellomeres; ratio of length from first to fifth flagellomeres: 1.7:1.2:1.1:1.1:1.0. Occipital carina complete, joining hypostomal carina above base of mandible.

MESOSOMA. Pronotum ( Fig. 16 ) unevenly shagreened, upper portion with transverse wrinkles. Mesoscutum ( Fig. 17 ) shagreened, lateral portions and median lobe with fine indistinct punctures, distance between punctures 0.5–2.0 × diameter of puncture. Scutoscutellar groove relatively wide, smooth, shiny. Scutellum evenly convex, shagreened. Anterior portion of postscutellum distinctly concave. Mesopleuron ( Fig. 18 ) unevenly shagreened, subanterior and lower portion with weak fine punctures, distance between punctures 1.5–5.0 × diameter of puncture. Speculum smooth, shiny, without sculpture. Upper end of epicnemial carina reaching front edge of mesopleuron and to 0.7 distance to subtegular ridge. Metapleuron slightly convex, sculpture as lower portion of mesopleuron. Ratio of length of hind tarsomeres from first to fifth: 4.5:2.1:1.6:1.0:1.3. Wings ( Fig. 19 ) hyaline. Fore wing with vein 1cu-a distal to M&RS by 0.2× length of 1cu-a. Areolet absent. Distance from vein 2rs-m to 2m-cu 1.5× length of 2rs-m. Postnervulus intercepted at middle. Hind wing vein 1-cu 1.5× as long as cu-a. Propodeum ( Fig. 20 ) evenly convex, with dense gray setae, sublateral portion shagreened; lateromedian longitudinal carinae and posterior transverse carinae complete, strong. Median portions of lateromedian longitudinal carinae combined, length of combined carina as long as area superomedia. Area basalis triangular. Area superomedia reversed triangular. Propodeal spiracle small, circular.

METASOMA. First metasomal tergite ( Fig. 21 ) approximately 1.9 × as long as posterior width, evenly narrowed anteriorly, shagreened, posterior margin smooth; latero-median carina almost entirely absent; dorso-lateral carinae distinct, complete except near spiracle; ventro-lateral carina distinct, complete; spiracle circular, located approximately at 0.4 of first metasomal tergite. Glymma large, deep. Second ( Fig. 22 ) and subsequent tergites shagreened. Second metasomal tergite 0.7× as long as posterior width; thyridium small, transversely elliptical. Upper and lower margins of ovipositor sheath ( Fig. 23 ) almost parallel. Ovipositor ( Fig. 23 ) relatively strong, compressed, subapical dorsal notch relatively deep and sharp.

COLORATION ( FIG. 12 ). Black, except for following: face, clypeus, mandible except teeth, maxillary palpi, labial palpi, ventral profile of pedicel, ventral apical half of scape, upper-posterior corners of pronotum, tegulae, anterolateral portion of mesoscutum, subtegular ridge, posterior portion of scutellum, postscutellum slightly, fore and mid coxae and all trochanters, metasomal sternites whitish yellow. Fore and mid femora yellowish brown, tibiae and tarsi and basal half of hind tibiae except basal end darkbrownish yellow. Hind coxa and femur brownish red. Posterior margin of second metasomal tergite and anterior median triangular sport of third tergite yellow. Posterior margins of third and subsequent tergites narrowly white. Pterostigma and veins blackish brown.

Male

Unknown.

Figures

Figs 12–14. Alexeter flaviventris sp. nov., holotype, ♀ (GSFGPM). 12. Habitus, lateral view. 13. Head, anterior view. 14. Head, dorsal view. Scale bars: 12 = 1 mm; 13–14 = 0.2 mm.

Figs 15–20. Alexeter flaviventris sp. nov., holotype, ♀ (GSFGPM). 15. Head, lateral view. 16. Pronotum, anterior view. 17. Mesoscutum and scutellum, dorsal view. 18. Mesosoma, lateral view. 19. Wings. 20. Propodeum, dorsal view. Scale bars: 15–18, 20 = 0.2 mm; 19 = 0.5 mm.

Figs 21–23. Alexeter flaviventris sp. nov., holotype, ♀ (GSFGPM). 21. First metasomal tergite, dorsal view. 22. Second and third tergites, dorsal view. 23. Apical portion of metasoma, lateral view. Scale bars: 21 = 0.1 mm; 22–23 = 0.2 mm.