Linycus Cameron 1903
Creators: name: Kikuchi, Namiki
name: Konishi, Kazuhiko
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Linycus

description: Genus Linycus Cameron, 1903   
 Linycus Cameron, 1903: 198 [  
 Type species: Linycus rufipes Cameron, 1903; monotypic]; Perkins, 1959: 67; Heinrich 1962: 777–783; Townes et al., 1965: 513; Townes & Townes, 1966: 273; Heinrich 1974: 178–179; Heinrich, 1977: 278–279; Tereshkin, 2009: 1454–1455.   
 Erythroischnus Cameron, 1904: 252 [  
 Type species: Erythroischnus annulicornis Cameron, 1904; monotypic].   
 Description based on Japanese species.   
 Head. Gena moderately narrowed behind eye in dorsal view; ocellar triangle weakly elevated above eyes; antennal sockets large, protruding anteriorly in dorsal view (Figs 2-B, 3-B). Internal margins of compound eyes parallel; antennal cavity of supra-antennal area expressed and polished; polished area of antennal cavity small; supra-antennal area with small and distinct tubercle between antennal sockets; supra-clypeal area rather convex, protruding anteriorly; clypeus small, moderately convex, transverse, with straight apical margin, clearly divided from supraclypeal area by furrow; anterior tentorial pits moderate, longish oval; labrum trapezoid shaped, with straight apical margin, strongly protruding from under clypeus (Figs 2-A, C, 3-A, D). Mandible slender, narrowed to apex, with small lower tooth (Fig. 2-C). Malar space almost as long as mandible base (Figs 2-A, C, 3-A, D). Occipital carina complete, weakened above mandibular base; dorsomedian part of occipital carina angled (Figs 2-B, 3-B); hypostomal carina slightly widened near mandibular base. Maxillary palpus long, 2nd segment almost triangular, flat and not bulging.   
 Antenna. Flagella bristle-shaped, long and slender, not flattened.   
 Mesosoma. Collar of pronotum short, transverse furrow of pronotum not interrupted by keel (Figs 2-D, 3-C). Pronotal base without angular prominence, but somewhat angled (Figs 2-E, 3-D). Mesoscutum strongly convex, notauli weakly developed on anterior 1/3 (Figs 2-D, E, 3-D, D. Scutellum highly elevated, dorsal surface moderately to strongly convex, with lateral carinae (Figs 3-G, H). Prepectal carina complete; subalar ridge rather thin; sternaulus indistinct, developed on anterior 1/3; postpectal carina absent (Figs 2-E, 3-D). Hind margin of metanotum with a triangle projection on each side of postscutellum (Figs 2-D, 3-C). Propodeum with costula, often weak; juxtacoxal carina and pleural carina indistinct; areola usually wide, hexagonal, anterior margin broadly truncate; apex of second lateral area with small tubercle (Figs 2-D, E, 3-C, D). Propodeum short in profile (Figs 2-E, 3-D). Propodeal spiracle small, circular to rounded (Figs 2-D, 3-C).   
 Legs. Slender and long. Fore and mid tarsomeres 2–5 weakly flattened, widened to apex, and with fine short hairs; spines on each tarsomere 4 moderately short, developed (Fig. 2-I).   
 Wings (Fig. 4). Areolet pentagonal (Fig. 4-A) or quadrangular (Fig. 4-B); single bulla on 1m-cu and 3rs-m, two bullae on 2m-cu; ramulus weakly developed. Hind wing with vein cu-a.   
 Metasoma. Amblypygous. Petiole in profile straight, flattened, clearly wider than deep, bending before base of postpetiole; in dorsal view, basal half weakly widened toward posterior; dorsomedian carina and dorsolateral carina present (Figs 2-F, G, 3-E, F). Gastrocoelus shallow; thyridium clearly developed and narrow (Figs 2-F, 3-E). Parathyridium normal, distinct (Figs 2-F, 3-E). Cercus with long setae; ovipositor sheath parallel sided with rounded apex, moderately long, and protruding behind apex of metasoma (Figs 2-F, G, 3-E, F).   
 Diagnosis. This genus can be distinguished from other genera of the tribe Platylabini by a combination of the following characteristics: surface of head dull; surpraclypeal area convex and protruding anteriorly; spines on each tarsomere 4 normally developed; costula present; propodeal spiracle circular; gastrocoelus shallow; cercus with long setae; ovipositor sheath rather long.   
 Distribution. Japan (2 spp.); Western Palearctic (3 spp.), Eastern Palearctic (2 spp.), Nearctic (4 spp.), Oriental (4 spp.) and Neotropical (1 sp.) regions.   
 Remarks. This genus resembles Cyclolabus in the supra-clypeal area rather convex, protruding anteriorly, and circular propodeal spiracle, but can be distinguished by the shape of gastrocoelus, and somewhat developed spines on tarsomeres. The following records are the first records of this genus from Japan.
description: Published as part of Kikuchi, Namiki & Konishi, Kazuhiko, 2021, A taxonomic revision of the genus Linycus Cameron, 1903 from Japan, pp. 546-558 in Zootaxa 4948 (4) on pages 548-549, DOI: 10.11646/zootaxa.4948.4.3, http://zenodo.org/record/4629381