Yezoceryx bicarinatus, 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 : 348-350

Yezoceryx bicarinatus sp. nov.

( Figure 2 )

Diagnosis. Body reddish yellow, except head dorsally black; scuto-scutellar groove with two curved carinae; first tergite 2.1× as long as its posterior width; first sternite with rounded swelling; ovipositor length about 2.4× length of hind tibia.

Material examined. Holotype: ♀ ( RMNH), Thua Thien-Hue, Phong Dien NR, nr base camp, 15 km W Phong My , 22.iii–6.iv. 2001, 100 m a.s.l., Malaise trap, C. v. Achterberg & R. de Vries leg. ; Paratypes: 1♂ ( IEBR), same data as holotype ; 1♂ ( RMNH), same data as holotype except the Malaise trap was set up at 50–100 m a.s.l. ; 2♂ ( RMNH), same data as holotype except Malaise trap was set up at 80–120 m a.s.l. ; 1♀ 2♂ ( IEBR), Thua Thien- Hue, Bach Ma NP, iv.2012, Malaise trap, H.T. Pham leg. ; 2♂ ( RMNH) 1♂ ( IEBR), 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 holotype female. Head. Antenna with 29 flagellomeres, first flagellomere 1.2× length of second; frons concave and polished medially, punctate laterally, carina between antennal sockets extending to face dorsally; face 0.7× as high as wide, densely, coarsely punctate, striato-punctate medially, pubescent, dorsally convex; clypeus punctate, about 0.45× as high as wide, with dense transverse striations at level of subapical margin extending to face ventrally, median tubercle indistinct; malar space equal to basal width of mandible; lower tooth of mandible longer than upper, inner margins of eyes divergent ventrally; diameter of lateral ocellus 0.7× ocellarocular distance; vertex with dense, small punctures; occipital carina evenly curved, ventrally meeting hypostomal carina about 0.7× basal mandible width from base of mandible.

Mesosoma. Epomia 1.1× mandible basal width; pronotum with striations across median groove and punctures at posterior corner; mesoscutum 0.8× as long as wide at anterior level of tegulae, with dense punctures, pubescent, convergence area of notauli with short longitudinal carina; scuto-scutellar groove with two curved carinae; scutellum convex, with dense punctures, pubescent, lateral carina present basally; postscutellum polished, impunctate; mesopleuron with sparse dorsally and dense ventrally small punctures, pubescent except smooth medially, epicnemial carina complete, sharply defined, sternaulus shortly indicated anteriorly, posterior transverse carina of mesosternum present medially; metapleuron polished, with small punctures, pubescent; propodeum punctate basally, with wrinkles laterally, anterior transverse carina strong, area basalis slightly wider than long, area dentipara well defined with wrinkles; fore basitarsus 1.8× second tarsomere; mid basitarsus 2.2× second tarsomere; hind leg with femur 3.3× as long as wide, 0.75× length of tibia, tarsus 0.7× tibia, basitarsus 2.3× second tarsomere, fifth tarsomere 2.3× longer than third. Fore wing length 5.8 mm, vein Rs&M slightly distad of cu-a, vein 2 rs-m opposite 2 m-cu, hind wing with first abscissa of vein Cu 1 equal to vein cu-a.

Metasoma. Tergites with small punctures, pubescent; first tergite 2.1× as long as posterior width, densely punctate except narrow smooth posterior and anterior bands, lateral longitudinal carina present anteriorly, not extending to spiracle; second tergite 0.4× as long as first tergite, slightly longer than third; first sternite with rounded swelling, sclerotized part of sternite extending 0.6 of distance to spiracle; ovipositor 2.4× as long as hind tibia; hypopygium 3.1× as long as second tergite.

Colour. Reddish yellow. Antenna black, except scape and pedicel yellow, flagellomeres 12 to 17 whitish; head black except face, clypeus, mandible, inner margin of eyes black median lobe of mesoscutum dark posteriorly, hind fifth tarsomere with distal half black, fore wings with well-defined distal spot and area below pterostigma infuscate.

Male. Similar to female except antenna varies from 30 to 33 flagellomeres, without median whitish band, head black at vertex only, mesoscutum without blackish area as in female, fore wing vein 2 rs-m varies from slightly basad, opposite to slightly distad of 2 m-cu.

Variation. Paratype female from Bach Ma NP has 32 antennal flagellomeres, its hypopygium 3.3× as long as second tergite length.

Comparison. In Wang (1993), the new species keys to Yezoceryx emeiensis Wang, 1982 . It differs from the latter in its whitish medial flagellomeres and its shorter ovipositor. In addition, the dorsal part of the head of Y. bicarinatus sp. nov. is black, more extensively so in females than in males. In Chao’s (1981) key, the new species resembles Yezoceryx wuyiensis Chao in general colour pattern. It differs from Y. wuyiensis in its shorter first tergite (2.1× as long as posterior width vs 3.5× in Y. wuyiensis ).

Etymology. The new species is named after the two prominent carinae crossing the scuto-scutellar groove.

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

Figures

FIGURE 2. Yezoceryx bicarinatus sp. nov.: a. lateral view; b. face; c. dorsal view of metasomal tergites; d. dorsal view of mesosoma; e. lateral view of hypopygium; 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.