Dentilabus iyoensis Kikuchi & Konishi, 2018

Kikuchi, Namiki & Konishi, Kazuhiko, 2018, Two new species of Dentilabus Heinrich (Hymenoptera: Ichneumonidae: Ichneumoninae) from Japan and Korea, with redefinition of the genus, Zootaxa 4524 (1), pp. 87-96 : 93-95

Dentilabus iyoensis Kikuchi & Konishi , new species.

Figs 3, 4 , 14 , 20–28 .

Type series. Holotype, ♀, JAPAN: Mt. Saragamine, Ehime Prefecture, Shikoku, 1. VI. 1955, Mutsuo Miyatake (EUMJ). Data on the label: “Shikoku / Mt. Sara / VI. 1, 1955 / M. Miyatake ”

Paratype, JAPAN: 1♂, [Sikoku] Komenono, Matsuyama City , Ehime Prefecture, 27. V. 1978, M. Kotani ( EUMJ) .

Coloration. Body ground color black and covered with short white setae ( Fig. 3, 4 ). Vertex with a pair of white spots along eye margin ( Fig. 20–22 ); suplaclypeal area with a pair of white line along eye margin in male ( Fig. 22 ). Flagellum with white semiannulus on flagellomeres 7–11 in female, 10–14 in male. Propodeal spine reddish brown ( Fig. 24 ). In female, fore and mid tibiae and tarsi reddish brown. In male, fore femur reddish brown, fore and mid tibiae whitish brown, and all tarsi yellowish white. Wing veins dark brown. Metasomal T2 with apical reddish brown band; T7 with broad white band on apex.

Female. Body length 8.7 mm.

Head. Surface of vertex and gena granulate; suplaclypeal area and clypeus granulate, with shallow, small punctures; malar space rather finely granulate. Head 1.9 × as wide as long in dorsal view; postocciput 0.5 × as wide as head in dorsal view; OOL/POL = 1.2 ( Fig. 20 ). Suplaclypeal area 1.8 × as wide as high; clypeus 1.6 × as wide as high ( Fig. 21 ). Mandibles 2.0 × as long as mandibular base; lower tooth 0.3 × as long as upper tooth length. Malar space 0.7 × as wide as base of mandible. Occipital carina not meeting hypostomal carina, fading out near hypostomal carina above base of mandible by 0.9 × width of mandibular base. Fifth segment of maxillary palpus 2.2 × as long as mandibular base.

Antenna. Flagellum 9.7 mm long, with 37 flagellomeres; apical flagellomere conical; 1st flagellomere 5.8 × as long as apical width and1.6 × as long as the 2nd.

Mesosoma. Surface of pronotum densely punctate except lower half weakly rugose ( Fig. 24 ); mesoscutum and dorsal surface of scutellum finely granulate, with dense punctures; postscutellum weakly rugulose ( Fig. 23 ); mesopleuron densely punctate except around mesopleural fovea sparsely punctate, and anterior margin striate; metapleuron densely rugose-punctate ( Fig. 24 ); propodeum coarsely rugose-punctate, area of areola coarsely rugose ( Fig. 23 ). Mesoscutum 1.4 × as long as wide. Notaulus developed on apical 1/3 ( Fig. 23 ). Sternaulus weakly developed apical half; postpectal carina absent. Lateral carinae of scutellum reaching apex, hind margin slightly carinated. Propodeum in profile, basal area flat and evenly slanted from base of areola; juxtacoxal carina present, indistinct; costula weakly zigzagged; pleural carinae weak; areola quadrangular, 1.2 × as long as wide and 0.3 × as wide as dorsal distance between propodeal spiracles; petiolar area 2.2 × as long as areola. Propodeal spiracle 1.8 × as long as wide.

Legs. Surface of legs coriaceous, except hind coxa with small punctures. Hind tibia 0.4 × as long as fore wing.

Wings ( Fig. 14 ). Fore wing 6.9 mm long; areolet 1.3 × as long as 3rs-m, 0.4 × as high as 2m-cu, almost pentagonal; Cu-a opposite Rs&M; ramulus slightly developed. Hind wing with cu-a 0.3 × as long as first abscissa of Cu1; 2 basal hamuli, 8 distal hamuli on R1 vein.

Metasoma. Surface of petiole polished; postpetiole and basal 1/4 of T2 finely rugose punctate; lateral area of petiole coarsely rugose-punctate; apical 3/4 of T2 and basal half of T3 densely punctate; T4–T7 coriaceous ( Fig. 25 ). Petiole bend obtuse angle; in profile the angle between petiole and postpetiole 100°; in dorsal view broadened posteriorly; T1 2.0 × as long as wide; dorsomedian carina distinct from base to spiracle position, and indistinct on postpetiole; Second tergite in dorsal view 0.9 × as long as wide at apex. Inter-thyridiae interval 0.8 × as long as thyridium; inter-thyridiae area not depressed.

Male. Body length 8.5 mm. As in female except for the following characters: first flagellomere 5.6 × as long as apical width; hind margin of scutellum distinctly carinated; male genitalia ( Fig. 27 ) with apex of paramere almost rounded, apex of penis valve not elongated and ventral margin of penis valve with a right-angled corner near middle.

Remarks. This species is quite different from other members of the genus Dentilabus and can easily be distinguished from the other known members of the genus by the following characters; presence of tyloids, ventrally incomplete occipital carina, pentagonal areolet, shallow gastrocoelus, and wider inter-thyridiae area without any depression. We could find only a pair of specimens that we examined here. These specimens were old, thus, to keep specimens in complete condition, we have not dissected them. It seems to be quite a rare species, and more specimens are required to clarifying the species limits and variability.

Figures

FIGURES 1–4. Habitus of Japanese Dentilabus spp. 1. D. nigripodus sp. n., holotype (female), 2. ditto, paratype (male, from Namakusa-dani), 4. D. iyoensis sp. n., holotype (female), 4. ditto, paratype (male). Scale bars = 1.0 mm.

FIGURES 13, 14. Wings of Japanese Dentilabus spp. 13. D. nigripodus sp. n., holotype, 14. D. iyoensis sp. n., holotype. Scale bars = 1.0 mm.

FIGURES 20–28. Dentilabus iyoensis sp. n. 20, 21, 23–26: holotype, 22, 27, 28: paratype. 20. head in dorsal view, 21, 22. head in frontal view, 23. mesosoma in dorsal view, 24. mesosoma in profile, 25. metasoma in dorsal view, 26. metasoma in profile, 27. male genitalia, 28. tyloids on male flagellum. Scale bars = 1.0 mm.