Metapelma beijingense Yang, 1996

Cao, Liang Ming, Achterberg, Cornelis van, Tang, Yan Long, Yang, Zhong Qi, Wang, Xiao Yi & Cao, Tian Wen, 2020, Redescriptions of two parasitoids, Metapelma beijingense Yang (Hymenoptera, Eupelmidae) and Spathius ochus Nixon (Hymenoptera, Braconidae), parasitizing Coraebus cavifrons Descarpentries & Villiers (Coleoptera, Buprestidae) in China with keys to genera or species groups, ZooKeys 926, pp. 53-72 : 53

Metapelma beijingense Yang, 1996 Figures 3 , 4 , 5

Metapelma beijingense Yang 1996: 236.

Material.

Holotype, ♀, China, Beijing, Xishan Experimental Forest Farm, 7.viii.1989, Yang Zhong Qi leg., from apricot trunk, deposited in Insect Museum, Chinese Academy of Forestry, Beijing, China; 6♀♀, 1♂, China, Guizhou Province, Zunyi City, 27°41'54.91"N, 106°54'40.29"E, pupae collected 10.v.2015 from carcasses of Coraebus cavifrons Descarpentries & Villiers under bark of dead Symplocos stellaris Brand, emerged into adults 15-18.v.2015, Tang Yan Long.

Redescription

(based on specimens from Guizhou; differences between Beijing and Guizhou populations are shown in the key below).

Female. Body length 5.3-5.9 mm; forewing length 3.1-3.2 mm (Fig. 3A ).

Color. Body generally dark with metallic tints (Fig. 3A ). In frontal view, head with lower half of frons and entire face, gena, and occiput bright metallic green, but upper half of frons and vertex with slight red tint (Fig. 3C ). Propleuron, apical half of mesopleuron in lateral view with metallic green tint (Fig. 4A ); V-shaped sulcus on mesonotum, apical half of axilla, metanotum bright metallic green (Fig. 3E ), basal 1/3 of 1st gastral tergite in dorsal view (Figure 4C ), and basal 2/3 of visible ovipositor sheath in lateral view with metallic green tint (Fig. 4B ). Lateral stripe on metacoxa and tergites 2-5 in lateral view varies in color from base to apex in metallic red, golden and green, successively (Fig. 4B ). Apical spur and basal 1/2 of 1st tarsal segment of mid leg white to pale yellow. Basal 1/5 of mesofemur yellow to brown. Outer margin of metatibia with basal 0.3-0.4 length white (Fig. 4C ). Fore wing subhyaline, infuscation paler posteriorly and extend beyond medial fold toward posterior margin, as well as along medial fold and along posterior margin of discal area basally; veins and setae dark brown; hind wing subhyaline (Fig. 4E ).

Head. Head with sparse long white setae. In dorsal view, head width 1.75 × its median length, eye occupy 1/3 of maximum width in dorsal view (Fig. 3B ), pilose, nearly as long as head; ocelli small, POL: OD: OOL = 2: 3: 4. In frontal view, head as wide as high; height of eye 0.6 × and mandible width 0.3 × head width; minimum width of frons 1/3 head width; face, gena, frons and vertex with tiny transverse strigate-rugose stripes. Scrobes short, no more than 1/3 length of scape. In lateral view, malar sulcus straight, 1/2 eye height. Mandibles bidentate (Figs 3B, C , 4A ). Dorsal margin of torulus slightly above lower ocular line, but its ventral margin distinctly below it (Fig. 3C ); antenna with a very short radicle, almost not evident; scape 3.8 × its maximum width, 3 × length of pedicel, 4.7 × length of anellus, and 2.2 × length of 1st funicular segment; pedicel 0.8 × of length 1st funicular segment; 1st funicular segment 0.9 × length of 2nd funicular segment (Fig. 3D ).

Mesosoma. Mesosoma length 2.4 × its maximum height. Pronotum and mesonotum with evenly distributed, dense, long white setae. Pronotum campaniform, length 1/2 of mesoscutum, with posterior margin incurved (Fig. 3E ). Mesoscutum as long as broad, V-shaped notauli differentiate a convex anteromedial lobe; scutellar-axillar complex with deep oblique crenulate scutoscutellar sutures. Scutellum with an inverted Y-shaped longitudinal carina. Metanotum wide bilaterally and narrowest medially with a deep fossa, with posterior margin carinate. Medial length of propodeum twice length of medial length of metanotum and 1/2 length of scutellum, smooth without carinae, but posterior margin carinate; spiracle oval, large, situated at about half length at lateral margin of propodeum (Fig. 3E ). In lateral view, mesopleuron entirely delicately reticulate, anterior lower margin with long setae, metapleuron shiny with dense setae (Fig. 4A ).

Legs. Profemur curved, 4.6 × as long as its maximum width and 1.2 × length of tibia; tarsus 1.6 × length of tibia, tibia with one spur 0.4 × as long as basitarsus; relative lengths of protarsal segments 1-5 = 15: 10: 7: 6: 7. Mid leg: femur 1.2 × length of tibia; tarsus as long as tibia, relative lengths of segments 1-5 = 30: 9: 7: 5: 6 (Fig. 4D ). Hind leg: femur 3.6 × its maximum width, 0.9 × length of metatibia 4.3 × its maximum width, with two equally long spurs apical-ventrally, spurs 1/6 as long as basitarsus; dorsal margin of metatibia evenly curved; metatarsus as long as metatibia, relative lengths of segments 1-5 = 60: 20: 15: 12: 15. Metafemur, metatibia and metatarsal segments 1-3 compressed (Fig. 4D ).

Wings. Fore wing extending beyond apex of metasoma to about middle of visible part of ovipositor sheath; basal cell bare but disc with dense setae except for slender, oblique bare band behind parastigma; submarginal vein 2.3 × length of marginal vein, marginal vein 0.7 × length of postmarginal vein and 2.25 × length of stigmal vein; R fold and Cu fold visible. Hind wing about 0.8 × as long as fore wing (Fig. 4E ).

Metasoma. Metasoma sessile, 0.8 × as long as head plus mesosoma combined; metasoma reticulate. Posterior margins of tergites 1-4 incurved medially; median length ratio of tergites 1-6 = 45: 20: 42: 49: 56: 35. Visible part of ovipositor sheath 0.5 × length of metasoma, about 0.29 × length of forewing, and 0.75 × length of metatibia (Fig. 4B, C ).

Male. Body length 5.0 mm, forewing 3.2 mm (Fig. 5A, B ), otherwise similar to female.

Remarks.

Metapelma beijingense is a solitary parasitoid with a parasitism rate of about 13.5%, based on seven individuals together with 34 buprestid pupae. The ratio of females to males is six.

Figures

Figure 3. Metapelma beijingense Yang, ♀, China, Guizhou. A Habitus, dorsal aspect B head, dorsal aspect C head, anterior aspect D antennae, lateral aspect E mesosoma, dorsal aspect.

Figure 4. Metapelma beijingense Yang, ♀, China, Guizhou. A Head and mesosoma, lateral aspect B metasoma, lateral aspect, C metasoma, dorsal aspect D mid and hind legs, lateral aspect E wings.

Figure 5. Metapelma beijingense Yang, ♂, China, Guizhou. A Habitus, dorsal aspect B habitus, ventral aspect.