Megalommum solaense Long, sp. nov.

Figs 24–34

Diagnosis. In frontal view, head 1.4 × as wide as long; in dorsal view, head 1.5 × as wide as long; eye length 3.2 × temple; ocelli in high triangle, POL: OD: OOL= 3: 5: 3 (Fig. 25); vein 1-M of fore wing thin, 3.6 × vein 1-CU1; m-cu thick and curved outward, 1.3 × vein 1-M (Figs 31, 32); basal length of second submarginal cell 4.3 × apical width (Fig. 32); in lateral view, length of mesosoma 1.7 × its height; hind femur slender, 4.6 × as long as wide (Fig. 29); first metasomal tergite length 1.3 × its apical width (Fig. 33); sculptured laterally, coriaceous medially and apically, lateral grooves punctate; second tergite sculptured; midbasal triangular area smooth, 0.7 × as long as tergite; second metasomal suture densely crenulate (Fig. 34); third tergite sculptured laterally, smooth medially; ovipositor sheath obliquely setose, 0.2 × as long as fore wing.

Material examined. Holotype, ♀, “Bracn. 960 ” (IEBR), NW Vietnam, Son La, Thuan Chau, Co Ma, forest, 21.3402° N 103.5321° E, 1200 m, 05.vi.2008, N.T.P Lien, P.H. Phong.

Description. Holotype, female, length of body 9.1 mm, fore wing 9.7 mm, antenna 8.6 mm, ovipositor sheath 2.0 mm (Fig. 24).

Head. Antenna with 62 flagellomeres, 0.9 × as long as fore wing; apical antennomere with distinct spine; in lateral view, scapus 1.7 × as long as wide; length of first flagellomere 1.3 × second (9: 7); first, second and penultimate flagellomeres 1.5, 1.2 and 1.7 × their maximum width, respectively; head 1.4 and 1.5 × as wide as long in anterior (frontal) and dorsal view respectively; in frontal view, face as wide as long (20: 25), depressed medially, rugose and sparsely setose (Fig. 26); eye length 1.9 × as long as its transverse width (35: 18); height of clypeus: inter tentorial distance: tentorial ocular distance = 5: 12: 4; clypeus separated from face with a transverse carina; distance between tentorial pits 3.0 × as long as distance from tentorial pit to eye margin (Fig. 26); malar space 0.6 × basal width of mandible; in lateral view, transverse width of eye 2.7 × as long as temple (Fig. 27); in dorsal view, length of eye 1.75 × as long as width (35: 20), and 3.2 × as long as temple (35: 11); ocelli large, POL: OD: OOL= 3: 5: 3 (Fig. 25); frons slightly depressed laterally, with fine median carina; vertex and temple smooth.

Mesosoma. Mesosoma 1.7 × its height (72: 42); mesoscutum smooth, setose, glabrous laterally; notauli distinct, shallow; scutellar sulcus rather deep, crenulate; scutellum smooth, setose; mesopleuron and metapleuron smooth, setose, glabrous antero-medially; medial area of metanotum without mid longitudinal carina anteriorly; propodeum smooth, setose.

Wings. Fore wing (Fig. 32): length of pterostigma 4.1 × its width; vein 1-M 3.6 × vein 1-CU1; vein 1-SR+M thin, almost abruptly curved subbasally; m-cu thick and curved outwards, 1.3 × vein 1-M; subdiscal cell distinctly narrower than discal cell, with narrow and glabrous sclerome (Figs 31, 32); ratio of length of veins r: 3-RS: SR1 = 17: 35: 57; 2-RS: 3-RS: r-m = 24: 35: 13; second submarginal cell elongate; basal length of second submarginal cell 4.4 × apical width (Fig. 32); vein CU1b triangular, strongly widened basally. Hind wing (Fig. 30): vein 2-SC+R quadrate; vein SR distinctly curved basally, parallel-sided apically (Fig. 30); vein 1r-m straight; M+CU:1-M:1r-m = 17: 77: 31; apex of vein SC+R1 with three curved hamuli.

Legs. Fore tibia 0.8 × fore tarsus (49: 59); ratio of lengths of fore femur: tibia: basitarsus: tarsus = 43: 49: 22: 59; hind femur slender (Fig. 29); hind femur, tibia, basitarsus 4.6, 11.9 and 6.8 × their maximum width (Figs 28, 29); outer and inner hind tibial spurs 0.35 × and 0.4 × as long as hind basitarsus; tarsal claw simple and with bristly ventrally.

Metasoma. First metasomal tergite 1.3 × as long as wide apically (46: 36), distinctly rugose with a midlongitudinal carina and a pair of lateral smooth longitudinal groove (Fig. 33); median area first tergite with sparse striate rugosities; second metasomal tergite 1.45 × as long as third tergite medially (29: 20), and 1.2 × as wide (basally) as long (36: 29) (Fig. 34); second tergite coriaceous, with sublateral depressed sparsely striate area; midbasal triangular area 0.7 × as long as tergite (20: 29), its lateral convergent grooves wide, shallow and crenulate (Fig. 34); thirdfifth tergites setose, with fine sparse punctures; ovipositor slightly curved, needle-shaped apically, without dorsal notch or nodus and ventral serrations, its sheath covered with dense oblique setae, 0.2 × as long as fore wing.

Colour. Body yellow; eyes brown; scapus and pedicellus yellow; flagellum dark brown in most length, except 11–12 apical flagellomeres yellow; for and middle legs yellow; hind leg brown, except hind tarsus yellow; wing membrane and veins yellow, except parastigma black; metasoma yellow, except second tergite latero-posteriorly and third tergite latero-anteriorly dark brown; ovipositor sheath brown; ovipositor yellow.

Male. Unknown.

Distribution. NW Vietnam (Son La).

Biology. Unknown.

Etymology. The new species is named after the type locality, Son La Province, Northwest Vietnam.

Key to Megalommum species (*) from Vietnam

1. Fore wing vein 1-CU1 postfurcal; subdiscal cell distinctly narrower than discal cell (Figs 31, 32); vein 1-M almost perpendicular, forming with vein M+CU1 straight angle; vein 1-SR+M very thin and almost abruptly curved subbasally; vein m-cu curved outwards (Fig 31); ovipositor slightly curved (Fig. 16).................................. M. solaense Long, sp. nov.

— Fore wing vein 1-CU1 antefurcal; subdiscal cell much broader discal cell (Figs 5, 20, 21); vein 1-M oblique, forming with vein M+-CU1 obtuse angle; vein 1-SR+M thicker and widely curved subbasally or medially; vein m-cu curved inwards (Figs 5, 20, 21)................................................................................................ 2

2. Hind femur more robust, 3.2 × as long as wide (Fig. 9); second submarginal cell of fore wing rather long, its basal length 4.3 × as long as wide apically (Fig. 5); fore wing vein 1-M 0.9 × vein 1-CU1; hind wing vein 1-M slightly curved basally (Fig. 6); lateral convergent grooves of midbasal triangular area of second tergite narrow and shallow, punctate (Fig. 8); ovipositor straight (Fig. 10).............................................................. M. hoabinhense Long, sp. nov.

— Hind femur slender, 4.8 × as long as wide (Fig.17); second submarginal cell of fore wing broader, its basal length 3.6 × as long as wide apically (Fig. 20); fore wing vein 1-M 1.6 × vein 1-CU1; hind wing vein 1-M thick and distinctly curved basally (Fig. 19); lateral convergent grooves of midbasal triangular area of second tergite wide, crenulate (Fig. 23); ovipositor slightly curved (Fig. 16)...................................................................... M. simulatum Long, sp. nov.

(*) Notes. The other Megalommum species from West Palaearctic and Oriental Regions were keyed by van Achterberg & Mehrnejad (2011).

Megalommum hoabinhense sp. nov. runs out from couplet 3a ( M. jacobsoni) in the key by van Achterberg & Mehrnejad (2011) because fore wing vein 1-SR+ M strongly curved medially; hind wing vein SR slightly curved subbasally, parallel-sided apically; pterostigma yellow with black spot apically; and hind coxa and femur yellow entirely.

Megalommum simulatum sp. nov. runs out from couplet 3a ( M. jacobsoni) in the key by van Achterberg & Mehrnejad (2011) because of slender hind femur, 4.8 × as long as wide; fore wing vein 1-M 1.6 × vein 1-CU1; and hind coxa and femur yellow entirely.

Megalommum solaense sp. nov. runs out from couplet 3 ( M. jacobsoni and M. pistacivorae) in the key by van Achterberg & Mehrnejad (2011) because fore wing vein 1-M 3.6 × vein 1-CU1; malar space 0.6 × basal width of mandible; hind femur more robust (4.6 × as long as its maximum width); ovipositor slightly curved.