Brachyzapus convexus, Pham & Broad & Matsumoto & Wägele, 2012

Pham, Nhi Thi, Broad, Gavin R., Matsumoto, Rikio & Wägele, Wolfgang J., 2012, First record of the genus Brachyzapus Gauld and Dubois (Hymenoptera: Ichneumonidae: Pimplinae) from Vietnam, with descriptions of six new species, Journal of Natural History 46 (27 - 28), pp. 1639-1661 : 1643-1646

Brachyzapus convexus sp. nov.

( Figure 2 )

Material examined

Holotype (female). Lao Cai, Hoang Lien NP, Fansipan Mt , 2320 m a.s.l., 24 April to 2 May 2000, Malaise trap, P. Q. Mai and M. T. Nguyen leg. ( RMNH).

Diagnosis

Inner margins of eyes slightly convergent medially; malar space 0.5 × basal width of mandible; scutellum with lateral carina present basally, laterally with weak transverse ridges; metasternum with two parallel transverse ridges at level of posterior angulation; propodeum with posterior transverse carina strong; metasoma tergites narrow, first tergite without distinct median longitudinal carina; first sternite weakly convex, rounded centrally.

Description

Body length 12.2 mm, fore wing 9.5 mm, ovipositor 2.7 mm.

Head. Antenna with 30 flagellomeres, first flagellomere 1.35 × length of second; diameter of lateral ocellus 1.15 × ocellar–ocular distance; frons impunctate and polished; inner margins of eyes slightly convergent medially; face 1.4 × as high as wide, pubescent, upper margin concave between antennal sockets; clypeus strongly convex, about 0.6 × as high as wide, apical margin thin, emarginate; malar space about 0.5 × basal width of mandible; mandible twisted and narrow, upper tooth much longer than lower tooth; occipital carina complete, meeting hypostomal carina about 1.25 × length of mandible basal width from mandible base.

Mesosoma. Epomia length 2 × mandible width, extending from collar to dorsal margin of pronotum; pronotum impunctate and polished laterally, collar pubescent dorsally; mesoscutum densely setose, with notauli deep, convergent at posterior 0.3 in shallow hollow; scutellum strongly convex, pubescent basally, laterally with weak transverse ridges, lateral carina present basally; mesopleuron moderately densely pubescent except median concave area bare and polished, mesopleural suture foveolate, epicnemial carina present on lower 0.6 of mesopleuron; metapleuron convex, bare and polished, pubescent dorsally along pleural carina, submetapleural carina forming small lobe anteriorly, angled posteriorly about 130 ◦; metasternum with two parallel transverse ridges from posterior angulation of submetapleural carina extending about 0.7 distance to median longitudinal groove; propodeum moderately convex, pubescent laterally, dorsally mostly bare, petiolar area polished, lateral longitudinal carina present on apical 0.5, posterior transverse carina strong. Legs slender, tibiae slightly swollen sub-basally, fore femur 4.8 × as long as wide; hind femur 5.9 × as long as wide, length 0.8 × tibia, tibia 10 × as long as apical width; basitarsus longer than following three tarsomeres combined, length 0.3 × tibia, 0.45 × tarsus, 2.4 × second tarsomere, fourth tarsomere very short, fifth 1.7 × as long as third. Fore wing with vein Rs&M slightly basad of cu-a, 2 rs-m about 0.7 × distance between 2 rs-m and 2 mcu, vein cu-a slightly inclivous, vein Cu 1 a separated from 1 m-cu by 1.3 × length of vein Cu 1 b; hind wing with first abscissa of vein Cu 1 1.2x as long as vein cu-a.

Metasoma. Metasoma 2 × longer than head and mesosoma combined; tergites coriaceous with dense, short hairs, except transverse smooth bands apically and first two tergites polished with scattered hairs; first tergite 2.7 × as long as apical width, median part convex, dorsolateral carina complete, weaker apically, median longitudinal carina indistinct; second tergite 0.85 × length of first tergite, 1.4 × as long as apical width, basal and apical oblique grooves moderately deep, rhombic area moderately convex; third tergite shorter than second tergite, basal and apical oblique grooves weak; first sternite with some transverse ridges basally, weakly convex and rounded centrally; ovipositor slightly up-curved at tip, length from tip of hypopygium 0.75 × length of hind tibia, lower valve slightly swollen medially, tapered to sharp point.

Colour. Black. Antenna yellowish brown, clypeus brown, mandible yellowish brown, palpi and tegula yellow; scutellum and post-scutellum reddish; legs reddish brown, except fore and mid coxae yellow, mid and hind trochantellus slightly darker; wings yellowish, pterostigma and veins brownish yellow; metasoma brownish posteriorly; ovipositor reddish.

Male. Unknown.

Distribution

Currently known only from Hoang Lien NP, Fansipan Mountain, Lao Cai Province, North Vietnam ( Figure 7 ).

Ecological note

The single specimen was collected in montane evergreen forest at an altitude of 2320 m a.s.l.

Comparison

Morphologically, the new species is most similar to Brachyzapus fansipanensis sp. nov. (see description below) and B. nitidus (Hao and Sheng) , which all have the posterior transverse carina of the propodeum strong and complete and the first tergite distinctly convex medially, without median longitudinal carinae. However, the new species can be distinguished from B. nitidus by its entirely brownish yellow antenna, without whitish flagellomeres subapically, and the more elongate first tergite (2.7 × as long as apical width versus 1.75 ×). It differs from B. fansipanensis sp. nov. by the smoother lateral side of the scutellum, metasternum and first sternite.

Etymology

This species is named after its medially convex first tergite.

Figures

Figure 2. Brachyzapus convexus sp. nov. holotype female: (A) lateral view; (B) dorsal view of head and mesoscutum; (C) wings; (D) ovipositor; (E) lateral view of mesosoma; (F) dorsal view of tergites 1–2; (G) face; (H) dorsal view of scutellum, metascutellum and propodeum; (I) metasternum and sternite 1.

Figure 7. Map showing the type locality of six new species of Brachyzapus.