Exetastes compressus, Watanabe & Sheng, 2018

Exetastes compressus sp. nov.

( Figs 1–13 View FIGURES 1–7 View FIGURES 8–13 )

Exetastes fukuchiyamanus: Sheng & Sun, 2014: 52 View in CoL , 437 (in part).

Holotype: CHINA: ♀, Xinbin , Laoning, 22. X. 2009, IT. ( GSFPM).

Paratypes: JAPAN: 1 ♀, Hyogo Pref., Kami Town, Niimi, Mikata-kogen , 12. X. 2012 , S. Fujie leg. ( KPMNH). CHINA: 1 ♀, Kuandian , Liaoning, 20. IX. 2006, M. - L. Sheng leg. ( GSFPM); 1 ♀, Kuandian , Liaoning, 29. IX. 2006 , C. Gao leg. ( GSFPM); 1 ♀, Kuandian , Liaoning, 5. X. 2006 , C. Gao leg. (GSFPM); 1 ♀, Kuandian, Laoning, 11. VIII. 2011, IT. (GSFPM); 1♀ & 13 ♂, baishilazi, Kuandian, Laoning, 11. IX. 2011, IT. (GSFPM); 1 ♀, Kuandian, Laoning, 15. IX. 2011, IT. (GSFPM); 1 ♀, baishilazi, Kuandian, Laoning, 6. X. 2011, IT. (GSFPM); 6 ♀ & 32 ♂, Kuandian, Laoning, 3. IX. 2015, M.- L. Sheng leg. ( GSFPM); 7 ♀ & 4 ♂, Kuandian, Laoning, 4. X. 2015, IT. ( GSFPM); 4 ♀, Kuandian, Laoning, 13 X 2015, IT. ( GSFPM); 1 ♂, Xinbin, Liaoning, 26 VIII 2009, IT ( GSFPM); 1 ♀ & 1 ♂, Xinbin, Laoning, 10. IX. 2009, IT. ( GSFPM); 2 ♀ 2 M, Xinbin, Laoning, 24. IX. 2009, IT. ( GSFPM); 2 ♂, Xinbin, Laoning, 8. X. 2009, IT. ( GSFPM); 2 ♀, Xinbin, Laoning, 21. VI. 2017, IT. ( GSFPM); 1 ♀, Shennongjia , Hubei, 10. X. 2011, Y. - Q. Li leg. ( GSFPM); 1 ♀, Mentougou, Beijing, 24. IX. 2014, IT ( GSFPM).

Description. Female (n=33). Body length 10.0– 12.5 mm.

Head 0.5–0.6 × as long as wide, covered with dense punctures and silver setae ( Figs 1–3 View FIGURES 1–7 ). Clypeus 0.5–0.6 × as long as wide, slightly convex in lateral view ( Fig. 4 View FIGURES 1–7 ). Face 0.5–0.6 × as long as wide, convex medially ( Figs 3, 4 View FIGURES 1–7 ). Length of malar space 0.47–0.5 × as long as basal mandibular width Mandible not strongly twisted ( Fig. 3 View FIGURES 1–7 ). OOL 0.8–0.9 × as long as POL. Antenna with 49–55 (HT: 53) flagellomeres. Fl1 1.6–1.8 × as long as Fl2. Apical flagellomeres except for distal segment widened, length less than width (or the same) ( Fig. 2 View FIGURES 1–7 ).

Mesosoma covered with dense punctures and silver setae ( Fig. 6 View FIGURES 1–7 ). Epomia absent ( Fig. 6 View FIGURES 1–7 ). Pleural carina of propodeum strong posteriorly, weak anteriorly. Propodeum covered with irregular rugae, with a pair of indistinct longitudinal ridge medially, without a pair of sublateral convexities ( Fig. 7 View FIGURES 1–7 ). Fore wing length 8.5–10.0 mm. Vein 1 m-cu with a ramulus ( Fig. 1 View FIGURES 1–7 ). Areolet large, receiving vein 2 m-cu at middle ( Fig. 1 View FIGURES 1–7 ). Vein Rs strongly sinuated basally ( Fig. 1 View FIGURES 1–7 ). Hind femur 6.2–6.25 × as long as maximum depth in lateral view. Longest spur of hind tibia shorter than half length of first tarsomere. Hind first tarsomere 2.0–2.1 × as long as second tarsomere. Tarsal claws pectinate ( Fig. 9 View FIGURES 8–13 ).

Metasoma strongly polished, covered with fine and sparse punctures ( Fig. 10 View FIGURES 8–13 ). T1 2.3–2.4 × as long as maximum width, covered with minute and transverse striae basally. T2 0.9–1.2 × as long as maximum width.

Punctures on T2 and T3 relatively dense on basal 0.3 ( Fig. 10 View FIGURES 8–13 ). T4-T7 strongly compressed ( Fig. 10 View FIGURES 8–13 ). Ovipositor sheath 0.3-0.4 × as long as hind tibia, weakly widened apically, covered with brown setae.

Colouration ( Figs 1–10 View FIGURES 1–7 View FIGURES 8–13 ). Body (excluding wings and legs) black, except for: clypeus reddish-brown ventrally; mandibular teeth tinged with reddish-brown; antenna with a median white band; collar, posterodorsal corner of pronotum, and subalar prominence whitish-yellow; scutellum with a yellow spot; metasomal sternites blackishbrown; ovipositor reddish-brown. Wings hyaline. Veins and pterostigma blackish-brown except for yellowishbrown wing base. Legs black to blackish-brown except for: apical part of fore femur, fore and mid tibiae and tarsi more or less tinged with yellowish-brown; hind second to fourth tarsomeres whitish-yellow to white.

Male (n=55). Similar to female. Body length 8.9–9.5 mm. Fore wing length 7.5–7.8 mm. Antenna with 49–55 flagellomeres. Lower-lateral portion of face, median portion of mandible, anterior and posterior sides of fore coxa, apical portion of mid coxa, ventral-apical portions of fore and mid femora, fore and mid tibiae and first to fourth tarsomeres, posterolateral portions of propodeum white ( Figs 11–13 View FIGURES 8–13 ).

Distribution. Japan (Honshu) and China ( Beijing, Hubei, and Liaoning).

Bionomics. The host is unknown. All of adult wasps collected in autumn.

Etymology. The specific name is from the strongly compressed metasomal tergites.

Remarks. We recognized only a single female from Japan and thus this species may be rare in Japan. This species is similar to E. fukuchiyamanus , but clearly separated by the following character states: hind first tarsomere 2.1 × as long as second tarsomere (2.4–2.7 × in E. fukuchiyamanus ); T2-T7 largely smooth dorsally ( Fig. 10 View FIGURES 8–13 ) (covered with dull-surface in E. fukuchiyamanus : Fig. 16 View FIGURES 14–18 ); apical segments of female flagellum with length less than width (or the same) ( Fig. 2 View FIGURES 1–7 ) (length equal to or greater than width in E. fukuchiyamanus ); dorsomedian area of collar nearly entirely white ( Figs 5, 6 View FIGURES 1–7 , 11, 13 View FIGURES 8–13 ) (at most with a pair of small yellowish-white spots in E. fukuchiyamanus : Figs 17, 17 View FIGURES 14–18 ).