A new species of Asecodes Förster (Hymenoptera, Eulophidae) and first record of A. reticulatum (Kamijo) from China, with a key to Chinese species

Abstract A new species of Asecodes Förster, A. medogensesp. nov. is described from Tibet, China and A. reticulatum (Kamijo) is reported from China for the first time. A key to all known species of genus Asecodes in China is provided.

The genus Asecodes can be easily separated from other genera in Entedoninae by: subtorular grooves present (Figs 2, 10); having a strong and complete occipital median sulcus which reaches from the occipital margin to the foramen magnum (Fig. 21), instead of a weak fold (Fig. 22). More characters of Asecodes can be seen in Hansson (1994) and Hansson (1996).
Before this study, there are only three species of Asecodes known from China, Asecodes sinense (Ling) was first described from China by Ling (2000), A. turcicum (Nees) and A. delucchii (Bouček) were reported from China by Ling (2000) and Zhang et al. (2007) respectively. This paper includes five species of Asecodes distributed in China, A. medogense sp. nov. is described as new to science, and A. reticulatum (Kamijo) is first reported from China. A key to all known Chinese species based on females is provided.

Materials and methods
Specimens were collected by Malaise traps and sweeping nets and were mounted on a card, or dissected and mounted in Canada Balsam on slides following methods described by Noyes (1982). Photos were taken with an Aosvi AO-HK830-5870T digital microscope or a digital CCD camera attached to an Olympus BX51 compound microscope. The quality of these photos was improved by using Helicon Focus 7 and Adobe Photoshop 2020. Measurements were made using the built-in software of Aosvi AO-HK830-5870T.
Type material is deposited in the insect collections at Northeast Forestry University (NEFU), Harbin, China.

Taxonomy
Key to Chinese species of the genus Asecodes (females)

1
Fore wing hyaline, without infuscate transverse band, and with three stigmal hairlines (Fig. 20)  Scape with apex of ventral margin curved smoothly in a wide arc (Fig. 11); meshes of reticulation on mesoscutum and mesoscutellum relatively coarser and larger (Fig. 12); disc of fore wing with sparse setation (Fig. 13)  Diagnosis. Female. Scape strongly compressed from side to side and expanded from base to apex, with apex of ventral margin curved nearly in right-angle; pedicel as long as F1; F3 distinctly paler than other segments (Fig. 3); mesoscutellum densely and entirely reticulated with small meshes; propodeum with groove along median anterior margin, without carina or plica (Fig. 4); fore wing with a complete infuscate transverse band below MV (Fig. 5).
Description. Female. Body length 0.8-0.9 mm. Antenna mainly dark brown, except F3 distinctly paler than other segments (Fig. 3). Vertex and frons above frontofacial sulcus metallic bluish-green, frons below sulcus golden green. Mesosoma dark brown with weak metallic blue tinges. Gaster dark brown to brown with weak metallic bronze reflections. Fore wing with a complete infuscate transverse band below MV (Fig. 5). All coxae and femora dark brown. Protibia mainly pale brown with basal part slightly daker; mesotibia mainly dark brown with apical 1/4 pale brown; metatibia dark brown. All tarsi with tarsomeres 1-3 pale yellow, tarsomere 4 dark brown.  (Fig. 3) inserted above level of lower margin of eyes. Subtorular grooves present. Scape reticulated, strongly compressed laterally and expanded from base to apex, about 2.1 times as long as its maximum width, with apex of ventral margin curved nearly in a right-angle. Pedicel as long as wide, and as long as F1. F1 quadrate, slightly shorter than F2 (about 0.8 times); F2 slightly longer than wide (about 1.2 times); pedicel and F1-F2 with strong and long setae. F3-F5 longer than wide and distinctly narrower than F2; F3 1.7 times as long as wide; F4 twice as long as wide; F5 narrowest, with a long terminal spine. Mesosoma (Fig. 4), 1.2 times as long as wide. Pronotum reduced, invisible in dorsal view. Mesoscutum, mesoscutellum and axillae entirely with strong reticulate sculpture, meshes on midlobe of mesoscutum and mesoscutellum small and dense (compared with A. reticulatum), but wider than that on lateral lobe of the mesoscutum and axillae; propodeum almost smooth; metascutellum and lateral panels of metanotum with weak and irregular sculpture. Notauli incomplete, indicated only in anterior part. Midlobe of mesoscutum with two pairs of setae. Anterior part of axillae advanced forward in front of level of anterior margin of mesoscutellum. Mesoscutellum as long as wide, with one pair of setae. Propodeum long, about 0.34 times as long as mesoscutellum, with a groove along median anterior margin, without carina or plica. Fore wing Speculum closed below, with two stigmal hairlines. Hind wing (Fig. 6), 5.2 times as long as wide. Legs (Fig. 8), with coxae distinctly reticulated; mesotibial spur as long as corresponding basitarsus; metatibial spur shorter than corresponding basitarsus. Metasoma (Fig. 7), gaster ovate, as long as mesosoma; petiole short, conical; first gastral tergite occupying nearly 1/4 length of gaster; ovipositor originates from about the anterior margin of second gastral tergite and slightly exserted beyond apex of gaster.
Etymology. The specific name is derived from the name of the collection locality of the type specimens.
Distribution. China (Tibet). Remarks. Asecodes medogense is similar to A. reticulatum in having the mesoscutellum entirely reticulate; pedicel nearly as long as F1; fore wing with an infuscate transverse band below MV. The new species differs from A. reticulatum in having scape with apex of ventral margin curved nearly in a right-angle (curved smoothly in a wide arc in A. reticulatum); meshes of reticulation on mesoscutum and mesoscutellum relatively denser and smaller (relatively coarser and larger in A. reticulatum); disc of fore wing with more dense setation than A. reticulatum.
Comments. Asecodes delucchii can be easily separated from other species distributed in China by its characteristic fore wing. An Indian species, A. zhui Jamali having a similar fore wing was described by Jamali et al. (2021). Asecodes delucchii differs from A. zhui in having the fore wing about 2.4 times as long as wide (fore wing more than three times as long as wide in A. zhui); with the longest marginal cilia 1/3-1/2 the maximum wing width (4/5 the maximum wing width in A. zhui).