Yezoceryx thaii, 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 : 366-368

Yezoceryx thaii sp. nov.

( Figure 16 )

Diagnosis. Face highly swollen, black medially; mesosoma and metasomal tergites 1-2 reddish; first tergite about 1.8× as long as its posterior width; first sternite with a blunt tubercle, ovipositor about 2.7× as long as hind tibia.

Material examined. Holotype: ♀ ( IEBR), Thua Thien-Hue, Bach Ma NP, 1.iv.2012, Malaise trap, T.H. Pham leg.

Description of female holotype. Head. Antenna with 28 flagellomeres, first flagellomere 1.1× length of second; frons concave and polished medially, punctate laterally; face densely, coarsely punctate, 0.65× as high as wide, swollen medially, laterally, ventrally with transverse striations; clypeus about 0.5× as high as wide, more finely punctate than face, with median and lateral tubercles; malar space equal to basal width of mandible; mandible with transverse striations proximally, lower tooth of mandible slightly longer than upper tooth, inner margins of eyes divergent ventrally; diameter of lateral ocellus 0.75× ocellar-ocular distance; vertex matt, with small punctures; occipital carina evenly curved, ventrally meeting hypostomal carina about 0.4× basal mandible width from base of mandible.

Mesosoma. Epomia equal to mandible basal width; pronotum densely striate, upper posterior corner with small, fine punctures; mesoscutum as long as wide at anterior level of tegulae, matt, densely punctate, convergence area of notauli with two sinuous carinae medially; scuto-scutellar groove with three carinae; scutellum with small punctures, pubescent, lateral carina present anteriorly; postscutellum polished, impunctate; mesopleuron with small punctures dorsally and anteriorly, medially polished, impunctate, ventral half with fine, medium-sized punctures, epicnemial carina weak dorsally, posterior transverse carina of mesosternum present medially; metapleuron densely punctate dorsally, medially with striations, ventrally smooth, without punctures; propodeum matt, area basalis wider than high, area externa with small punctures, pubescent, area dentipara defined with some longitudinal striations, area superomedia confluent with polished area petiolaris, pleural parts of anterior and posterior transverse carinae present; fore basitarsus 2.4× second tarsomere; mid basitarsus 2.6× second tarsomere; hind leg with femur 3.1× as long as wide, 0.8× length of tibia, tarsus 0.8× tibia length, basitarsus 2.3× second tarsomere, fifth tarsomere 2.2× longer than third. Fore wing length 7.7 mm, vein Rs&M slightly distad of cu-a, vein 2 rs-m opposite 2 m-cu, first abscissa of hind wing vein Cu 1 equal to cu-a.

Metasoma. Tergites relatively polished, with small punctures, pubescent; first tergite 1.8× as long as posterior width, medially densely punctate, lateral longitudinal carina present anteriorly, not reaching to spiracle; second tergite 0.5× as long as first tergite and 1.2× as long as third, with small punctures on anterior half; first sternite with weak tubercle; ovipositor about 2.7× as long as hind tibia, hypopygium 1.9× as long as second tergite.

Colour. Reddish to reddish brown. Antenna black, except scape, pedicel and first flagellomere yellowish, flagellomeres 10–16 white; frons with dull yellow inner orbits; face, clypeus and mandible yellow except face medially black, ventrally brownish, gena and vertex black; mesosoma and first two tergites reddish, tergite 3 onwards black with narrow posterior brown margins; ovipositor brown, hypopygium and ovipositor sheath black; fore and mid legs reddish, hind leg black except trochanter and basal half of trochantellus yellow; wings hyaline, fore wing with infuscated apical margin.

Male. Unknown.

Comparison. This species resembles Yezoceryx elatus Wang, 1982 in having the face conspicuously elevated medially. It differs from the latter by the entirely reddish mesosoma and metasomal tergites 1-2.

Etymology. Named after Dr Thai Hong Pham, an entomologist from the Vietnam National Museum of Nature (VNMN), who collected the holotype.

Distribution. Currently known only from Bach Ma NP, Thua Thien Hue Province and Chu Yang Sin NP, Dak Lak Province, Vietnam ( Figure 19 ).

Figures

FIGURE 16. Yezoceryx thaii sp. nov.: a. dorsal view; b. face; c. lateral view of mesosoma; d. dorsal view of propodeum; e. lateral view of hypopygium.

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.