Longipectus, Pham & Cao, 2025

Pham, Nhi Thi & Cao, Nga Thi Quynh, 2025, A new genus and three new species of the subfamily Phygadeuontinae (Hymenoptera: Ichneumonidae) from northern Vietnam, European Journal of Taxonomy 1026, pp. 236-249 : 237-238

Genus Longipectus gen. nov.

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Diagnosis

Head globular; occipital carina widely separated from posterior ocelli, ventrally meeting hypostomal carina about 0.6–1.0 × basal mandibular width from base of mandible; mesosoma elongate and dorsoventrally compressed, 0.7–0.8 × as long as metasoma, with notauli distinct on anterior 0.5–0.7 of mesoscutum; mesopleuron with episternal scrobe connected to mesopleural furrow by a groove; posterior transeverse carina of mesosternum short and v-shaped; propodeum with area petiolaris separated from area superomedia when the latter defined; first tergite short, about 0.4–0.7 × as long as second tergite, with ventrolateral carina complete; first and second tergites with longitudinal wrinkles; metasomal tergites 2 and 3 with laterotergite separated by distinct suture; ovipositor relatively slender.

Etymology

The name of the new genus is derived from the Latin words ‘ longus ’, meaning ‘long’, and ‘ pectus ’, meaning ‘thorax’, referring to its long thorax. Gender: masculine.

Type species

Longipectus yagi gen. et sp. nov.

Description

Head globular. Occipital carina thickened, complete and widely separated from posterior ocelli, ventrally meeting hypostomal carina about 0.6–1.0 × basal mandibular width from base of mandible. Face as high as wide to higher than wide. Clypeal suture indistinct. Mandible short, 2.0–2.5 × as long as median width, weakly to distinctly narrowed towards apex, teeth sharp. Maxillary palp long to moderately long, reaching anterior to center part of mesopleuron. Basal flagellomeres long and narrow, F1 7.0–11.0 × as long as wide. Mesosoma 0.7–0.8 × as long as metasoma. Pronotum 0.3–0.4 × as long as mesosoma, epomia absent or present as a short stub, dorso-medially of pronotum, just behind pronotal collar without or with weak median carina. Mesoscutum 1.2–1.9 × as long as maximum width. Notauli distinct on anterior 0.5–0.7 of mesoscutum. Scutellum weakly to moderately convex, lateral carina present basally. Mesopleuron with epicnemial carina present ventrally or dorsally, sternaulus present or absent, episternal scrobe connected to mesopleural furrow by a groove. Posterior transverse carina of mesosternum short and v-shaped. Propodeum gradually sloping in lateral view, area petiolaris separated from area superomedia when the latter defined, propodeal spiracle small and round. T1 short, 0.4–0.7 × as long as T2, polished, dorsolateral and ventrolateral carinae distinct. T1–T2 with longitudinal wrinkles. T2–T3 with laterotergites separated by distinct sutures. Ovipositor thin, straight, lower valve with teeth apically. Ovipositor sheath 0.18–0.38 × as long as hind tibia length. Legs long, hind femur 5.3–6.2 × as long as wide, hind tarsus longer than hind tibia, hind basitarsus nearly 0.5 × as long as hind tarsus. Fore wing length 3.5–5.1 mm, vein 3rs-m absent, vein 2m-cu inclivous, with two bullae.

Key to species of Longipectus gen. nov.

1. Mesosoma extremely elongate, 0.8 × as long as metasoma ( Fig. 6); pronotum 0.4 × as long as mesosoma ( Fig. 7E); propodeum with densely transverse striations dorsally (except smooth posteriorly), area superomedia absent, posterior transverse carina forming a crest ( Fig. 7H); fore wing smoky medially ( Figs 6, 7G) ………………………………… L. yagi gen. et. sp. nov.

– Mesosoma less elongate, about 0.7 × as long as metasoma ( Figs 1, 3); pronotum 0.3 × as long as mesosoma ( Figs 2E, 4E); propodeum punctate to matt, area superomedia weakly defined or open laterally, posterior transverse carina normal; fore wing hyaline ( Figs 2G, 4G) ………….2

2. Antenna with normally cylindrical flagellomeres; sternaulus distinct, reaching hind margin of mesopleuron ( Fig. 2E); propodeum matt, area superomedia weakly defined ( Fig. 2H); ovipositor sheath 0.33–0.38 × as long as hind tibia length…... L. hagiangensis gen. et. sp. nov.

– Antenna with posterior flagellomeres thickened and flattened ventrally; sternaulus indistinct ( Fig. 4E); propodeum punctate, area superomedia open laterally ( Fig. 4H); ovipositor sheath 0.18–0.19 × as long as hind tibia length ………................................ L. planus gen. et. sp. nov.