Eustenogaster fraterna ( Bingham, 1897 )

Saito, Fuki & Kojima, Jun-Ichi, 2007, A taxonomic revision of the hover wasp genus Eustenogaster van der Vecht (Insecta: Hymenoptera; Vespidae, Stenogastrinae), Zootaxa 1556, pp. 1-30 : 16-19

Eustenogaster fraterna ( Bingham, 1897)

Ischnogaster fraterna Bingham, 1897: 377 , 378.

Female. Body length (head + mesosoma + first two terga) 17.5–20.0 mm; forewing length 13.0– 14.5 mm.

Head in frontal view about 1.1 times wider than high ( Fig. 57 ). Clypeus convex, with extreme apex sharply pointed; supraclypeal area irregularly punctate, particularly area between antennal sockets covered with clathrate punctures, but small, flat area below anterior ocellus impunctate. Ocelli close to each other (Fig.

9); distance between anterior and posterior ocelli shorter than diameter of posterior ocellus; distance between posterior ocelli less than their diameter; anterior ocellus 0.28–0.32 mm wide, 0.24–0.30 mm long, about 1.5 times wider than posterior ocellus (diameter 0.14–0.20 mm); distance between inner eye margin and posterior ocellus as long as or slightly longer than width of anterior ocellus.

Pronotum and scutum densely punctate; interspace between punctures smaller than puncture; posterolateral part of pronotum and dorsal part of mesepisternum rugosely punctate. Lateral furrow of pronotum shallow. Scutum with median longitudinal carina developed anteriorly. Scutellum strongly convex, hairly, densely punctate, with short median carina. Metanotum rather strongly convex, hairly, and with anterior margin rugosely punctate. Propodeum hairly, with shallow, small punctures.

First metasomal tergum 7.2–8.4 mm long, about 6.2 times as long as its own maximum width, 7.4 times longer than the maximum height, in dorsal view more or less parallel-sided and gradually widened toward posterior margin only in its posterior one-fifth (Fig. 10); second tergum convex dorsally (Fig. 11); sixth tergum with small tubercle (Fig. 12).

Color: Body black, except for ventral surface of posterior two-thirds of first tergum dark reddish-brown, and the following parts yellow: clypeus except for black apex and lateral margins, large square spot below each antennal socket, narrow band in each posterodorsal margin of pronotum, scrobal spot, inverted L-shaped mark below scrobal spot, paired lateral spots on scutellar disk, anterior band on metanotum, paired posterodorsal spots on propodeum, paired basal spots (sometimes fused) on second tergum, anterolateral parts of third tergum, and paired spots on third sternum. Legs brown; following parts yellow: outer side of fore femur; tibia and first tarsomere of fore leg; lateral spot on mid-tibia; variable-sized spot on dorsal surface of hind coxa. Wings semihyaline, pale brown, darker along anterior margin of forewing; veins brown.

Male. Body length (head + mesosoma + first two terga) 17.5–18.5 mm; forewing length 13.5–14.4 mm. Structure and coloration similar to female, but clypeus less convex and with apex bluntly angled; mandibular teeth rounded apically (Fig. 13); second tergum less strongly convex dorsally (Fig. 14).

Genitalia: Digitus beak-shaped, apically with few hairs ( Fig. 59 D). Ventral margins of pennis valves minutely serrated only in the proximal part (Fig. 16).

Material examined. Thailand: 1ɗ ( SKYC), Khao Soi Dao WS, rainforest, Chanthaburi Prov., East Thailand, 4.vi.2001, SkY; Malaysia: Malay Peninsula: 10Ψ3ɗ ( IUNH / FSHU), Fraser’s Hill, [6Ψ2ɗ, ix.1966; 1Ψ, ix.1967; remaining specimens without data of collection but with the following data: 1ɗ, FH 61–2–1; 1Ψ, FH 61–2–2; 1Ψ, FH 61–2–3; 1Ψ, FH44–1]; 2Ψ2ɗ ( GMNH), Fraser’s Hill, Selangor, xii.1987, S Turillazzi; 1Ψ ( RMNH), Jor Rd. milestone 23, 700m, Cameron Highlands, Perak–Pahang, 13.iii.1963, MAL.

Distribution: India: Assam, Sikkim; Myanmar; Thailand; Malaysia: Peninsular Malaysia.

Figures

FIGURE 57. Facial marking pattern of Eustenogaster species.

FIGURE 59. Male genitalia in Eustenogaster species. (A) E. gibbosa, in ventral view. (B – M) aedeagus in lateral view; (N – Y) vollsela with digitus in lateral view; (B, N) E. agilis; (C, O) E. fulvipennis; (D, P) E. fraterna; (E, Q) E. scitula; (F, R) E. calyptodoma; (G, S) E. gibbosa; (H, T) E. hauxwellii; (I, U) E. micans; (J, V) E. latebricola Saito, sp. nov.; (K, W) E. palavanica; (L, X) E. luzonensis; (M, Y) E. spinicauda Saito, sp. nov..