Xorides juglanse Sheng, Broad & Sun, 2023

Sun, Shu-Ping, Lü, Jun, Broad, Gavin R., Li, Tao & Sheng, Mao-Ling, 2023, Two new species of Xorides Latreille (Hymenoptera, Ichneumonidae) from China, with notes on biology and a key to species known from China, European Journal of Taxonomy 890 (1), pp. 115-135 : 124-128

Xorides juglanse Sheng, Broad & Sun sp. nov.

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Figs 9–19

Diagnosis

Antenna with 20 flagellomeres; flagellomeres 16–18 ( Figs 9 , 13 ) distinctly stouter, with six projecting “peg-like bristles”. Propodeum ( Fig. 16 ) with rough irregular wrinkles. Tergite 2 ( Fig. 18 ) with basolateral oblique groove and transverse shallow depression slightly beyond middle, medially with dense irregular longitudinal wrinkles. Ovipositor sheath 1.6 × as long as hind tibia. Ovipositor slightly down-curved, subapical portion of dorsal valve ( Fig. 19 ) with two distinct tubercles. Head, mesosoma and all tergites entirely black. Flagellomeres 12–15 white. Fore wing irregularly infumate along M&RS and beneath pterostigma.

Etymology

The name of the new species is based on the plant the type series was reared from.

Material examined

Holotype CHINA • ♀; Liaoning Province, Kuandian Manzu Autonomous County; 18 May 2017; reared from borers in trunks of Juglans mandshurica Maxim. ; Jun Lü leg.; CBDPC.

Paratypes CHINA • 3 ♀♀; same locality as for preceding; 30 Aug.–23 Sep. 2021; reared from Juglans mandshurica Maxim. ; Jun Lü and Cheng-Jia Liao leg.; CBDPC .

Description

Female

MEASUREMENTS. Body length 5.4 to 6.0 mm. Fore wing length 3.7 to 4.2 mm. Ovipositor sheath length 1.7 to 2.0 mm.

HEAD. Face ( Fig. 10 ) approximately 1.8 × as wide as long, evenly convex, median portion with irregular wrinkles and sparse fine punctures, laterally densely punctate; upper margin with strong median projection towards frons. Clypeal suture distinct, median portion between anterior tentorial pits straight. Clypeus with distinct uniformly arched sub-basal transverse ridge; apical portion inclined, depressed, with indistinct punctures. Apical portion of mandible with fine median longitudinal groove. Subocular sulcus distinct. Malar space 1.1 × as long as basal width of mandible, with sparse punctures. Gena ( Figs 11–12 ) almost shiny, with strong oblique longitudinal wrinkles. Vertex ( Fig. 12 ) shiny, with uneven punctures. Postocellar line approximately 1.7 × as long as ocular-ocellar line. Frons almost flat, with uneven fine punctures. Antenna with 20 flagellomeres; ratio of length from first to fifth flagellomeres: 1.4:1.1:1.0:1.0:1.0; flagellomeres 16–18 ( Figs 9 , 13 ) distinctly stouter, with six “peg-like bristles”. Occipital carina complete; genal carina joining hypostomal carina distinctly above base of mandible.

MESOSOMA. Subanterior margin of pronotum ( Fig. 15 ) with longitudinal wrinkles; lateral concavity narrow, with short transverse wrinkles; posterior portion with large dense irregular punctures. Epomia strong. Mesoscutum ( Fig. 14 ) with uneven punctures; punctures in postero-median portion very dense, irregular, strongly coalescent appearing to be rugulose-punctate. Notaulus weak, with short wrinkles. Scutellum ( Fig. 14 ) almost flat, with irregular punctures. Metanotum with transverse ridgeshaped convexity, anterior portion deeply obliquely concave. Mesopleuron ( Fig. 15 ) almost shining, upper anterior portion with denser punctures than lower-posterior portion; speculum relatively large; mesopleural fovea shallow, indistinct. Posterior transverse carina of mesosternum weak, complete. Metapleuron roughly sculptureed, with strong irregular reticulate wrinkles. Juxtacoxal carina absent. Submetapleural carina complete, anterior portion strongly convex. Ventral profiles of fore and mid tibiae slightly incurved, subbasal portions with angled concavities.Front side of front tibia with four spines, apex with three pegs. Ratio of length of hind tarsomeres from first to fifth approximately: 5.6:2.1:1.7:1.0:2.7. Wings slightly gray, hyaline. Fore wing with vein 1cu-a basal to M&RS by approximately 0.4 × length of 1cu-a. Distance between 2rs-m and 2m-cu 1.4× as long as 2rs-m. Postnervulus intercepted at lower 0.3. Hind wing vein 1-cu 1.5× as long as cu-a. Propodeum ( Fig. 16 ) in lateral view evenly convex, with almost complete carinae. Area basalis smooth, shiny, anterior portion deeply concave. Area externa with dense irregular punctures. Area dentipara with indistinct oblique wrinkles and irregular punctures. Area superomedia hexagonal, with indistinct transverse wrinkles and sparse fine punctures, connecting to costula slightly behind middle.Areas petiolaris and lateralis with irregular reticulate wrinkles.Apophysis strong. Propodeal spiracle obliquely elliptical.

METASOMA. First tergite ( Fig. 17 ) approximately 1.5 × as long as posterior width, strongly and evenly narrowed to base; anterior portion smooth, shiny; medially with fine punctures; posterior half with longitudinal irregular wrinkles; anterior half of latero-median carina distinct, strong; dorso-lateral carina indistinct; spiracle almost circular, small, located slightly anterior to middle of first tergite. Tergite 2 ( Fig. 18 ) distinctly trapezoidal, 0.7× as long as anterior width, 0.6× as long as posterior width, anteriorly with distinct oblique groove, with a transverse shallow depression slightly posterior to middle; medially with distinct irregular longitudinal wrinkles, unevenly punctate peripherally. Tergites 3 ( Fig. 18 ) and subsequent with distinct brownish gray setae. Tergite 3 slightly dilated medially, approximately 0.5× as long as median (maximum) width; antero-medially with irregular wrinkles, laterally with distinct punctures, posteriorly with fine indistinct wrinkles. Tergite 4 with dense transverse fine wrinkles. Tergites 5–7 almost shiny. Apex of tergite 8 truncate. Ovipositor sheath 1.6× as long as hind tibia. Ovipositor ( Figs 9 , 19 ) evenly and weakly down-curved, distally straight; subapical portion of dorsal valve with two distinct tubercles; lower valve with 7 distinct ridges.

COLOUR ( Fig. 9 ). Black, except for following: antenna brownish black, flagellomeres 12 to 15 white; clypeus and mandible dark brown; all coxae almost entirely black; dorsal side of fore tibia brown, ventral side and tarsomeres 1–4 yellowish brown; base of mid tibia, ventral side and tarsomeres 1–4 brown, dorsal side dark brown; hind femur blackish brown, ventrobasal portion of tibia and tarsomeres 1–4 yellowish brown; pterostigma blackish brown, proximally white; veins of wings brownish black.

Male

Unknown.

Biology

Hosts. The unknown (presumably coleopteran) host is a wood-borer of Juglans mandshurica Maxim. (Juglandaceae) .

Host foodplant. Juglans mandshurica Maxim. (Juglandaceae) .

Differential diagnosis

The new species is most similar to X. propinquus (Tschek, 1869) , but can be easily distinguished from the latter by the preceding key, including features of the frons sculpture, width of notauli, fore wing venation, etc.

Figures

Figs 9–11. Xorides juglanse Sheng, Broad & Sun sp. nov., holotype, ♀ (CBDPC). 9. Habitus, lateral view. 10. Head, anterior view. 11. Head, lateral view.

Figs 12–15.Xorides juglanse Sheng, Broad & Sun sp. nov., holotype, ♀ (CBDPC). 12. Head, dorsal view. 13. Apical portion of antenna, lateral view. 14. Mesoscutum and scutellum, dorsal view. 15. Mesosoma, lateral view.

Figs 16–19. Xorides juglanse Sheng, Broad & Sun sp. nov., holotype, ♀ (CBDPC). 16. Propodeum, dorsal view. 17. Tergite 1, dorsal view. 18. Tergites 2–4, dorsal view. 19. Apical portion of ovipositor, lateral view.