Exetastes compressus, Watanabe & Sheng, 2018

Watanabe, Kyohei & Sheng, Mao-Ling, 2018, Taxonomic notes on Exetastes fukuchiyamanus Uchida, 1928 (Hymenoptera, Ichneumonidae, Banchinae), with description of a new species from Japan and China, Zootaxa 4399 (2), pp. 281-288 : 282-285

Exetastes compressus sp. nov.

( Figs 1–13 )

Exetastes fukuchiyamanus: Sheng & Sun, 2014: 52 , 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 ). Clypeus 0.5–0.6 × as long as wide, slightly convex in lateral view ( Fig. 4 ). Face 0.5–0.6 × as long as wide, convex medially ( Figs 3, 4 ). Length of malar space 0.47–0.5 × as long as basal mandibular width Mandible not strongly twisted ( Fig. 3 ). 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 ).

Mesosoma covered with dense punctures and silver setae ( Fig. 6 ). Epomia absent ( Fig. 6 ). 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 ). Fore wing length 8.5–10.0 mm. Vein 1 m-cu with a ramulus ( Fig. 1 ). Areolet large, receiving vein 2 m-cu at middle ( Fig. 1 ). Vein Rs strongly sinuated basally ( Fig. 1 ). 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 ).

Metasoma strongly polished, covered with fine and sparse punctures ( Fig. 10 ). 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 ). T4-T7 strongly compressed ( Fig. 10 ). Ovipositor sheath 0.3-0.4 × as long as hind tibia, weakly widened apically, covered with brown setae.

Colouration ( Figs 1–10 ). 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 ).

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 ) (covered with dull-surface in E. fukuchiyamanus : Fig. 16 ); apical segments of female flagellum with length less than width (or the same) ( Fig. 2 ) (length equal to or greater than width in E. fukuchiyamanus ); dorsomedian area of collar nearly entirely white ( Figs 5, 6 , 11, 13 ) (at most with a pair of small yellowish-white spots in E. fukuchiyamanus : Figs 17, 17 ).

Figures

FIGURES 1–7. Exetastes compressus sp. nov., female (holotype)—1, lateral habitus; 2, apical part of antenna; 3–5, head, frontal (3), lateral (4), and dorsal (5) view; 6, mesosoma, lateral view; 7, propodeum, dorsal view.

FIGURES 8–13. Exetastes compressus sp. nov., female (8–10, holotype) and male (11–13, paratype)—8, left hind tarsus, anterioraspect; 9, left hind tarsal claw; 10, metasoma, dorsalview; 11, lateral habitus;12, 13, head, frontal (12) and dorsal (13) view.

FIGURES 14–18. Exetastes fukuchiyamanus Uchida, 1928, female (14–16) and male (17, 18)—14, 17, lateral habitus; 15, 18, head, frontal view; 16, T2, dorsal view.