Dolichomitus melanomerus ( Vollenhoven, 1878 )

Pham, Nhi Thi, Broad, Gavin R. & Zwakhals, Kees, 2012, First record of the genus Dolichomitus Smith (Hymenoptera: Ichneumonidae: Pimplinae) from Vietnam, with description of one new species, Zootaxa 3519, pp. 77-84 : 81-82

Dolichomitus melanomerus ( Vollenhoven, 1878)

Ephialtes melanomerus Vollenhoven, 1878 . Tijdschr. Ent. 21: 48. Holotype: Ƥ, Java (RMNH) Dolichomitus melanomerus: Townes & Townes (1960)

Ephialtes tinctipennis Cameron, 1899 . Mem. Proc. Manchester Lit. Phil. Soc. 43: 151. Holotype: Ƥ, India: Khasi Hills (BMNH). Dolichomitus tinctipennis: Townes, Townes & Gupta (1961)

Dolichomitus melanomerus tinctipennis: Gupta & Tikar (1976)

Diagnosis. Face slightly shorter than wide, with dense, moderate-sized punctures, long hairs; mandibular teeth equal in length; mesoscutum and mesopleurum with moderately dense, small punctures; tubercles on tergites 3–5 distinct, punctate; ovipositor down-curved at tip, 7.6x length of hind tibia, lower valve with five preapical and eight apical grooves.

Description based on Vietnamese specimens ( Figs 2 , 3 ) Female. Head. Antenna with 37 flagellomeres, first flagellomere 1.2x length of second; diameter of lateral ocellus 0.9x ocellar-ocular distance; frons with deep longitudinal impression laterally, polished, with several hairs; face 0.9x as high as wide, with dense, moderatesized punctures, long hairs; clypeus pubescent, 0.45x as high as wide, basally flat, apex thin, emarginate; malar space about 0.25x basal width of mandible; upper tooth equal to lower tooth; occipital carina complete, concave mediodorsally, meeting hypostomal carina at about 0.25x basal mandible width from base of mandible; vertex and gena polished, with moderately dense, small punctures, pubescent.

Mesosoma. Epomia present, as long as mandible basal width; pronotum polished, impunctate, except dorsal margin and posterior corner punctate, pubescent; mesoscutum 1.25x as long as wide at anterior level of tegulae, with moderately dense, small punctures, pubescent, notauli distinct on anterior 0.3 of mesoscutum, nearly extending to front level of tegulae; scutellum moderately convex, pubescent, lateral carinae absent; mesopleuron with moderately dense, small punctures, pubescent, polished and impunctate posteriorly near mesopleural suture, epicnemial carina extending nearly to groove below subalar prominence; metapleuron polished with moderately dense punctures, pubescent, except polished, impunctate ventral half, submetapleural carina complete, forming anterior lobe; propodeum densely punctate, with long hairs, mediodorsal furrow impunctate, above petiolar area with transverse striae; pleural area with dense, punctures, verging on striae, long hairs, propodeal spiracle oval, about 2.0x as long as wide, not touching pleural carina. Hind leg with femur 5.5x as long as wide, length 0.6x tibia, tarsus longer than tibia, basitarsus 0.5x tarsus, 2.5x second tarsomere, fifth tarsomere slightly longer than third. Fore wing with areolet nearly triangular, vein 2 rs-m equal to 3 rs -m; cu-a opposite Rs & M; hind wing with vein M + Cu straight, first abscissa of vein Cu 1 about 0.4x length of vein cu-a.

Metasoma. Tergites densely punctate except apical transverse smooth bands; first tergite 1.8x longer than its apical width, dorsolateral carina weakly complete, median longitudinal carina present on basal half; second tergite 1.6x length of apical width, 1.25x length of first tergite, 1.25x length of third, basal oblique groove deep, extending about half length of tergite; tergites 3–5 with distinct, punctate tubercles; apical transverse smooth bands on tergites 2–4 extending about 0.2x length of each tergite; ovipositor down-curved at tip, 7.6x length of hind tibia, lower valve with five preapical and eight apical grooves.

Colour. Black. Clypeus basally, tegulae and first two legs reddish brown; wings yellowish brown, pterostigma and veins brown; ovipositor reddish.

Male. Antenna with 31–33 flagellomeres; face as long as wide, more closely punctate than in female; frons with deep longitudinal impression laterally; mandible with teeth equal in length; malar space short, about 0.1x mandible basal width; epomia length 0.7x basal width of mandible; mesoscutum 1.2x as long as wide at anterior level of tegulae, with dense, fine punctures, pubescent; mesopleuron, metapleuron and propodeum as in female; fore wing with vein 2 rs-m about 0.85x vein 3 rs -m; hind wing with first abscissa of vein Cu 1 about 0.3–0.4x length of vein cu-a; metasomal tergites with sculpture as in female; subgenital plate deep laterally, elongate medially; gonosquama as in figure 3a; mesosternum black to reddish black, fore and mid legs yellow, hind leg with coxa to base of tibia reddish, remainder infuscate.

Remarks. The Vietnamese specimens key readily to D. melanomerus using Gupta & Tikar’s (1976) key and closely resemble the holotype (in BMNH) of D. melanomerus tinctipennis . Gupta & Tikar separated the subspecies of D. melanomerus mainly on the basis of colour patterns of the legs. Whether these differences reflect genetic separation of populations is unknown.

Distribution. Previously known from Russia, India, Sri Lanka, Taiwan, Japan, Indonesia, and the Philippines ( Yu et al. 2005), this is the first record of this species from Vietnam ( Fig. 4 ).

Material examined. Vinh Phuc, Tam Dao NP: 1Ƥ ( IEBR), 900 m a.s.l, 13.v.2003, hand net, T. V. Hoang leg.; Hoa Binh, Hang Kia-Pa Co NR: 23 ( IEBR), 10–20.iv.2002, Malaise trap, L. D. Khuat leg.; 13 ( RMNH), 1319 m a.s.l, 20°44’35 N 104°53’ 45E, 10–24.x.2009, Malaise trap, C. v. Achterberg & R. de Vries leg.

Figures

FIGURE 2. Dolichomitus melanomerus (female) a. lateral view of mesosoma; b. wings; c. metasomal tergites 1 – 3; d. ovipositor tip; e. face; f. dorsal view of head and mesoscutum; g. dorsal view of scutellum and propodeum.

FIGURE 3. Dolichomitus melanomerus (male) a. lateral view of gonosquama; b. genital plate.

FIGURE 4. Map showing the type locality of Dolichomitus lami sp. nov. (●) and distribution of Dolichomitus melanomerus (▲) in Vietnam.