Syzeuctus orientalis, Riedel, 2022

Riedel, Matthias, 2022, Contribution to the knowledge of Oriental Syzeuctus FÖRSTER (Hymenoptera, Ichneumonidae, Banchinae), with description of six new species, Linzer biologische Beiträge 54 (1), pp. 257-273 : 268-269

Syzeuctus orientalis nov.sp. ( figs 3 , 8 , 14 , 20 )

H o l o t y p e: (♁) Lao: Prov. Hua Phan Prov., Phon-Pan, Umg. Ort Ban Saleui, 20°13´30´´N / 103°59´26´´E, 1350-1900 m, 03- 05.04.2014 KJa, leg. C. Holzschuh & natives (Linz). P a r a t y p e: (♁) Lao: Prov. Hua Phan Prov., Phon-Pan, Umg. Ort Ban Saleui, 20°13´30´´N / 103°59´26´´E, 1350-1900 m, 27- 28.04.2014 KJa, leg. C. Holzschuh & natives (Linz).

D e s c r i p t i o n: ♁: Body length 13.5-14.0 mm. Length of fore wing 10 mm. Antenna with 51 flagellomeres, filiform; 1 st flagellomere 5.0× longer than wide and 0.64× as long as eye; preapical flagellomere square. Temple very short, strongly and roundly narrowed behind eye, dorsally 0.2× as long as eye. OED 1.1 × and OOD 1.5× ocellar diameter. Vertex with scattered punctures. Frons moderately swollen and densely punctate laterally, slightly impressed and partly smooth medially. Face densely punctate, inner eye margins moderately divergent ventrally. Clypeus moderately convex, 1.9× wider than long, almost smooth and with long erected setae; apical margin rounded. MI 0.4-0.5. Mandible with baso-ventral lamella, lower tooth shorter than upper tooth. Genal carina reaching mandibular base.

Mesosoma densely punctate, covered with grey setae, 1.40× longer than high. Frontoventral edge of pronotum moderately curved. Side of pronotum densely punctate dorsally, with short longitudinal rugae at posterior margin, pronotal groove partly smooth. Mesopleuron densely punctate; speculum large, smooth. Epicnemial carina low, pleural part short, ending at ventral third of mesopleuron. Propodeum densely punctate, centrally with some transverse rugae. Pleural carina and apical transverse carina present. Legs slender; hind femur 6.0-6.1× longer than wide. Hind metatarsus 0.73× as long as hind femur. 2 nd hind tarsomere 1.35× as long as 3 rd one. Hind claw without teeth, strongly bent apically (c. 90°). Areolet with long stalk, stalk as long as areolet; vein 2mcu reaching areolet in its distal 0.8. Vein 1cu-a postfurcal by 2× its width. Postnervulus intercepted behind its middle. Hind wing with 9-10 distal hamuli.

Metasoma slender; 1 st tergite 2.4-2.6× longer than wide, with fine scattered setiferous punctures laterally, almost smooth medially and apically, shining. 2 nd tergite 1.70-1.75× longer than wide, with dense coarse punctures. 3 rd tergite 1.48× as long as wide, with dense but superficial punctures.

Color: Black, head and mesosoma with extended yellow coloration. Antenna black, ventral spots on scape and pedicel and basal half of flagellum yellowish ventrally. Head mainly yellowish; median frons, stemmaticum and occiput black. Propleuron, wide frontal and upper margins of pronotum, tegula, subtegular ridge, large and central spot of mesopleuron confluent with yellow ventral third of mesopleuron and entire mesosternum, large spots on upper division and central metapleuron, scutellum and postscutellum, area spiracularis frontally and wide posterior triangular band of propodeum confluent with yellow spots on metapleuron yellow. 1 st to 2 nd or 3 rd tergite black medially, following tergites ± reddish; 1 st tergite yellow in basal 2/5, 2 nd to 4 th tergites reddish-yellow basally; 1 st to 4 th tergites with apical yellow bands, following tergites with narrow yellow hind margins. Sternites yellowish. Coxae and trochanters yellow; hind coxa and trochanter with dorsal black spots. Fore and mid legs yellowish; fore femur with reddish stripe dorsally; mid tarsus ochreous. Hind femur and tibia red; hind tibia ± infuscate apically; hind tarsus black. Wings hyaline, without apical infuscation. Pterostigma brown.

♀ unknown.

R e m a r k: This new species resembles the ♁ of Syzeuctus immediatus CHANDRA & GUPTA, but differs by more extended yellow body coloration and hyaline wings without dark apical spot. Since the corresponding ♀ is unknown yet, this species is not included in the key of Oriental Syzeuctus below.

Figures

Figs 1-3: Habitus from dorsal: (1) Syzeuctus laoticus nov.sp. ♀ holotype (HT); (2) S. siamensis nov.sp. ♀ HT; (3) S. orientalis nov.sp. ♁ paratype (PT).

Figs 4-9: Basal tergites from dorsal: (4) Syzeuctus achterbergi nov.sp. ♀ HT; (5) S. floresiensis nov.sp. ♀ HT; (6) S. genator nov.sp. ♀ HT; (7) S. laoticus nov.sp. ♀ HT; (8) S. orientalis nov.sp. ♁ PT; (9) S. siamensis nov.sp. ♀ HT.

Figs 10-15: Faces from frontal: (10) Syzeuctus achterbergi nov.sp. ♀ HT; (11) S. floresiensis nov.sp. ♀ HT; (12) S. genator nov.sp. ♀ HT; (13) S. laoticus nov.sp. ♀ HT; (14) S. orientalis nov.sp. ♁ HT; (15) S. siamensis nov.sp. ♀ HT.

Figs 16-21: Heads from frontal: (16) Syzeuctus achterbergi nov.sp. ♀ HT; (17) S. floresiensis nov.sp. ♀ HT; (18) S. genator nov.sp. ♀ HT; (19) S. laoticus nov.sp. ♀ HT; (20) S. orientalis nov.sp. ♁ HT; (21) S. siamensis nov.sp. ♀ HT.