Yezoceryx rufus, Achterberg, 2017

Achterberg, Cornelis Van, 2017, First record of the genus Yezoceryx Uchida (Ichneumonidae: Acaenitinae) from Vietnam, with descriptions of nine new species, Zootaxa 4311 (3), pp. 345-372 : 362

Yezoceryx rufus sp. nov.

( Figure 13 )

Diagnosis. Reddish with head and metasomal tergite 3 onwards blackish; propodeum polished, area basalis square; first tergite 2.6× as long as posterior width; first sternite with weak anteriorly projecting hook; ovipositor 4.0× as long as hind tibia

Material examined. Holotype: ♀ ( RMNH), Dak Lak, Chu Yang Sin NP, Krong K’Mar , 2-10.vi.2007, 740– 900 m a.s.l., Malaise trap, C. v. Achterberg & R. de Vries leg.

Description of female holotype. Head. Antenna with 26 flagellomeres, first flagellomere 1.1× length of second; frons concave and polished medially, punctate laterally, carina between antennal sockets extending some distance on to face; face 0.7× as high as wide, with dense, moderate-sized punctures, convex dorsally; clypeus punctate, about 0.5× as high as wide, basally flat, lateral margin slightly up-curved, subapical margin present, with median and lateral tubercles; malar space equal to basal width of mandible; lower tooth of mandible slightly longer than upper, inner margins of eyes divergent ventrally; diameter of lateral ocellus 0.7× ocellar-ocular distance; vertex with dense, fine punctures; occipital carina evenly curved, ventrally meeting hypostomal carina about 0.5× basal mandible width from base of mandible.

Mesosoma. Epomia equal to mandible basal width; pronotum subpolished, with wrinkles along posterior margin and fine punctures dorsally; mesoscutum 0.9× as long as wide at anterior level of tegulae, with dense, fine punctures, pubescent; convergence area of notauli with two short median carinae and wrinkles laterally; scutoscutellar groove with six carinae; scutellum convex, with small punctures, pubescent, lateral carina extending to summit; postscutellum polished, impunctate, mesopleuron with small punctures, pubescent ventrally, epicnemial carina sharp, complete, sternaulus distinct on anterior 0.5, posterior transverse carina of mesosternum present medially; metapleuron polished, with small punctures, pubescent; propodeum polished dorsally with sparse punctures in area externa, pleural parts of anterior and posterior transverse carinae present, area basalis square, lateral longitudinal carina erased ventrally leading to ill-defined area dentipara; fore basitarsus 2.3× second tarsomere; mid basitarsus 2.5× second tarsomere; hind leg with femur 3× as long as wide, 0.7× length of tibia, tarsus 0.8× tibia length, basitarsus 2.5× second tarsomere, fifth tarsomere 2.3× as long as third. Fore wing length 4.7 mm, vein Rs&M slightly distad of cu-a, vein 2 rs-m about 2.5× distance between 2 rs-m and 2 m-cu, hind wing with first abscissa of vein Cu 1 0.5× as long as vein cu-a.

Metasoma. Tergites with small punctures, pubescent; first tergite 2.6× as long as posterior width, with sparse punctures anteriorly, lateral longitudinal carina present anteriorly, not extending to spiracle; second tergite 0.4× as long as first tergite, 1.1× as long as third; first sternite with weak anteriorly projecting hook, extending nearly to level of spiracle; ovipositor about 4.0x as long as hind tibia, hypopygium 2.0× as long as second tergite.

Colour. Reddish. Antenna brownish yellow basally, dark brown apically, flagellomeres 10 to 14 whitish; head black posteriorly, face and gena dark, clypeus and mandible yellow (except teeth apically black); mesoscutum darkened around notauli, metasomal tergite 3 onwards blackish, ovipositor sheath light brown with white apical tip, fore wings with apical part and area below pterostigma infuscated.

Male. Unknown.

Comparison. In colour pattern, the new species is most similar to Yezoceryx thaii sp. nov. It can be distinguished from Yezoceryx thaii by the longer first tergite (2.6× as long as posterior width vs. 2.0×) and square area basalis (vs much wider than high). Yezoceryx rufus sp. nov. also resembles Yezoceryx testaceus ( Tosquinet, 1903) in general colouration. It differs from the latter by its antenna with a median white band, lateral lobe of mesoscutum without black marks, and metasomal tergite 3 onwards blackish.

Etymology. Named after its colour pattern.

Distribution. Currently known only from Chu Yang Sin NP, Dak Lak Province, Central Highlands of Vietnam ( Figure 19 ).

Figures

FIGURE 13. Yezoceryx rufus sp. nov.: a. lateral view; b. face; c. lateral view of head and mesosoma; d. dorsal view of head and mesosoma; e. lateral view of first metasomal tergite; f. dorsal view of propodeum.

FIGURE 19. Map of sampling sites of Yezoceryx spp in Vietnam: 1. Cao Bang Province; 2. Bac Kan Province; 3. Vinh Phuc Province, 4. Son La Province; 5. Hoa Binh Province; 6. Ninh Binh Province; 7. Nghe An Province; 8. Thua Thien-Hue Province; 9. Kon Tum Province; 10. Dak Lak Province; 11. Dong Nai Province.