ACTA ENTOMOLOGICA MUSEI NATIONALIS PRAGAE

A new species of the genus Enicospilus Stephens, 1835, E. kikuchii sp. nov., which belongs to the ichneumonid subfamily Ophioninae, is described based on two specimens that were collected in Saitama Prefecture of Honshû and Kagoshima Prefecture of Kyûshû in Japan. Enicospilus kikuchii sp. nov. belongs to the E. antefurcalis species-group. A key to species of the group and additional couplets for the key to Indo-Papuan Enicospilus species are provided.

The Enicospilus antefurcalis species-group is characterized by several features, with the shape and number of sclerites of the fore wing fenestra, surface structure and shape of the mandible, and surface sculpture of the mesopleuron and metapleuron especially important.The group comprises 14 described species in the Old World (GAULD & MITCHELL 1981, GAULD 1982, YU et al. 2012).The author recently had an opportunity to investigate the Japanese specimens belonging to this species-group, and identifi ed a species that has not been described yet.Hence, a new species of the E. antefurcalis species-group is described here from Japan.In addition, the key to species of the group and additional couplets for the key to Indo-Papuan species of the genus, which was provided by GAULD & MITCHELL (1981), are provided.

Materials and methods
The holotype specimen was provided by Namiki Kikuchi and deposited in the National Institute for Agro-Environmental Sciences (NIAES), Tsukuba, Japan, and the paratype specimen was from the Kusigemati collection at the Laboratory of Systematic Entomology of Hokkaido University (SEHU), Sapporo, Japan.
A stereoscopic microscope (SMZ1500, Nikon, Tokyo, Japan) was used for morphological observation.Multi-focus photographs for fi gure 1 were taken using a single-lens refl ex camera (D90, Nikon, Tokyo, Japan) fi tted with a micro-lens (AF Micro-Nikkor 60 mm f/2.8D,Nikon, Tokyo, Japan) and a teleplus teleconverter (N-AFD ×2 Teleplus MC7, Kenko, Tokyo, Japan), and were stacked using Zerene Stacker.Figures 6-9 were taken using a scanning electron microscope (SEM) (JSM-6010LV, JEOL, Tokyo, Japan).The specimen for SEM observation was not coated and was observed under high vacuum and an accelerating voltage of 10kV.All fi gures were edited in Adobe Photoshop© CS5.
Abbreviations and indices:  Diagnosis.The genus is characterised and distinguishable from any other ophionine genera by the following combination of character states: mandible weakly to strongly tapered and more or less twisted (Figs 2,3,6); ocelli large, and sometimes adjacent or close to eyes (Figs 2-4); occipital carina usually complete; posterior transverse carina of mesosternum usually complete; discosubmarginal cell of fore wing with fenestra and often with sclerites (Fig. 5); ramellus of fore wing usually absent (Fig. 5); inner mesal surface of fore tibial spur without a membranous fl ange; and outer distal margin of mid and hind trochantelli simple, and usually without a decurved tooth.Distribution.Afrotropical, Australasian, Nearctic, Neotropical, Oceanic, Oriental, and Palaearctic Regions (YU et al. 2012).Bionomics.Several lepidopterous families (e.g., Lasiocampidae, Noctuidae, and Notodontidae) are reported as hosts (e.g., GAULD & MITCHELL 1981, GAULD 1988, BROAD & SHAW 2016).Remarks.According to GAULD (1985), the Enicospilus genus-group contains the following fi ve subgroups: Orientospilus subgroup comprising three genera, Ophiogastrella subgroup comprising a single Neotropical genus, Stauropoctonus subgroup comprising two genera, Leptophion subgroup comprising three genera, and Enicospilus subgroup comprising fi ve genera, including the genus Enicospilus.

Enicospilus antefurcalis species-group
Diagnosis.This group is characterized and distinguished from the other groups by the following combination of character states: interocellar area generally yellowish brown; outer surface of mandible with a diagonal hirsute groove between upper proximal corner and base of teeth (Figs 2, 3); mandible evenly narrowed (Figs 2, 3); mesopleuron more or less punctostriate or roughly and strongly striate (Fig. 6); metapleuron usually diagonally punctostriate to striate (Figs 6, 7); fenestra of fore wing usually with the central, distal, and proximal sclerites (Fig. 5); central sclerite of fenestra usually strongly pigmented and positioned in middle to distal part of fenestra and rarely completely lacking (Fig. 5); proximal sclerite of fenestra distinct and large (Fig. 5); Rs+2r straight to slightly sinuate (Fig. 5); and fore wing with ICI = 0.4-0.8,CI = 0.2-0.5,SDI = 1.1-1.5 (Fig. 5).Differential diagnosis.The group considerably resembles the E. ramidulus species-group, and these groups share the following characteristics: interocellar area generally yellowish brown; outer surface of mandible with a diagonal hirsute groove between upper proximal corner and base of teeth (Figs 2, 3); proximal sclerite of fore wing distinct and large (Figs 2, 3); Rs+2r straight to slightly sinuate, not strongly sinuate or arcuate (Fig. 5).However, when focusing only on Japanese species of both of the E. antefurcalis and E. ramidulus speciesgroups, species of the E. antefurcalis species-group are distinguishable from the E. ramidulus species-group by the following combination of character states: characteristic mandible, i.e., mandible evenly narrowed and its profi le usually moderately long (Figs 2, 3), but mandible proximally narrowed and distally parallel-sided or cylindrical, and its profi le usually long and slender in the E. ramidulus species-group; at least part of the mesopleuron and/or metapleuron punctostriate to striate (Figs 6, 7), but mesopleuron and metapleuron regularly punctate, i.e., mesopleuron punctate to punctostriate and metapleuron usually punctate in the E. ramidulus species-group.Remarks.Most of the species-groups of Enicospilus, including the E. antefurcalis species-group, were defi ned by Gauld (e.g., GAULD 1988, GAULD & MITCHELL 1981), but these species-groups are merely hypotheses that have not actually been phylogenetically tested; thus, there is no particular evidence that the Enicospilus species-groups are monophyletic, although they are often readily recognizable.Nevertheless, a comprehensive phylogenetic research is strongly necessary to reveal the relationships between species within the genus.The group previously comprised 14 described species: E. aciculatus (Taschenberg, 1875) and E. melanocarpus Cameron, 1905 from the Australasian, Eastern Palaearctic, Oceanic, and Oriental Regions; E. antefurcalis (Szépligeti, 1908), E. bicoloratus Cameron, 1912, E. polemus Gauld, 1982, andE. watshami Gauld, 1982 only from the Afrotropical Region; E. laqueatus (Enderlein, 1921) from the Afrotropical and Oriental Regions; E. marathwadensis Nikam, 1980 only from the Oriental Region; E. ruscus Gauld & Mitchell, 1978 from the Afrotropical and Oceanic Regions; E. sauteri (Enderlein, 1921) from the Eastern Palaearctic and Oriental Regions; E. xaivus Gauld & Mitchell, 1981, E. xuthus Gauld & Mitchell, 1981, and E. ypsilon Gauld & Mitchell, 1981 only from the Australasian Region; E. kalveus Gauld & Mitchell, 1981 only from Oceanic Region (GAULD & MITCHELL 1981, GAULD 1982, YU et al. 2012).

Differential diagnosis.
Within the E. antefurcalis species-group, this new species closely resembles E. melanocarpus in morphology, although distinct in colour, but they can be distinguished from each other by the following combination of characteristics: mesosoma, T1, T2, and T5-8 dark-brown to black in E. kikuchii, but usually most of body yellowish brown and T5-8 usually blackish in E. melanocarpus; and metapleuron roughly diagonally punctostrigose in E. kikuchii, but uniformly punctate or fi nely diagonally punctostriate in E. melanocarpus.Enicospilus kikuchii also resembles E. combustus (Gravenhorst, 1829) and E. nigropectus Cameron, 1905, within the Palaearctic Region, in its colour pattern.However, E. combustus and E. nigropectus do not belong to the E. antefurcalis species-group and are distinguishable  from E. kikuchii by the characteristics presented to the species-group already.Additionally, the latter species is easily distinguishable from any other species of the E. antefurcalis species-group using the key (see below).Description.Female (holotype) (Figs 1-9).Body length ca.20.5 mm.Head (Figs 2-4) with FI = 0.6 (Fig. 2); GOI = 2.8 (Fig. 3).Lower face 0.8 times as wide as high (Fig. 2), weakly polished, entirely covered with punctures and setae.Clypeus 1.7 times as wide as high (Fig. 2), polished with punctures and setae, moderately convex in lateral profi le (Fig. 3), its lower margin impressed (Fig. 2).Malar space 0.4 times as long as basal width of mandible (Figs 2, 3).Mandible evenly narrowed, its outer surface with a diagonal hirsute groove between upper proximal corner and base of teeth (Figs 2, 3).Upper tooth of mandible 1.5 times as long as lower one (Figs 2, 3).Frons, vertex and gena weakly polished with sparse setae.Posterior ocellus not contiguous to eye, but large and moderately close to eye (Figs 2-4).Antenna with 59 fl agellomeres.First fl agellomere 5.2 times as long as wide and 1.3 times as long as second fl agellomere.20th fl agellomere 2.1 times as long as wide.
Legs (Figs 1, 8).Distal 0.6 of outer surface of fore tibia with sparse short spines (Fig. 8).Hind coxa 1.7 times as long as wide.Hind trochanter 1.3 times as long as trochantellus in ventral view.Hind trochantelli simple.Hind femur 0.9 times as long as tibia.Hind basitarsus 1.7 times as long as second tarsomere.Fourth hind tarsomere 3.0 times as long as wide.Hind tarsal claw pectinate.
Colour (Fig. 1).Head entirely yellowish brown except dark brown to black apex of mandible and median part of frons.Mesosoma entirely dark brown to black except yellowish brown margin of pronotum, mesoscutum, mesopleuron, scutellum, metapleuron, propodeum, and entire anterior area of propodeum.Wing cells hyaline.Sclerites of wings yellowish brown, venation and setae dark brown to black.Legs yellowish brown except all coxae that are dark brown to black.T1-2, T5-8 and ovipositor sheath dark brown to black; T3-4, S2-4, and ovipositor yellowish brown.
Male.Very similar to female except for the following characters.Body length ca.22.0 mm.Head with GOI = 2.9.Apex of antennae incomplete.First fl agellomere 5.0 times as long as wide.20th fl agellomere 2.2 times as long as wide.
Legs.Hind basitarsus 1.8 times as long as second tarsomere.
Colour.Mesosoma entirely dark brown to black except reddish brown margin of pronotum, mesoscutum, mesopleuron, scutellum, metapleuron, propodeum, and entire anterior area of propodeum.Bionomics.Unknown.Etymology.The specifi c name is derived from the collector of the holotype specimen, Mr Namiki Kikuchi (Hokkaido University), who is one of the greatest young Japanese ichneumonologists.Distribution.Japan: Honshû (Saitama Pref.) and Kyûshû (Kagoshima Pref.).Remarks.Unfortunately, in this study, the author could only locate two type specimens.However, the specimens represent a distinct new species within the genus and the speciesgroup.Moreover, it is easily distinguishable from any other Indo-Papuan Enicospilus species based on the addition of the following couplets for the key to Indo-Papuan Enicospilus species by GAULD & MITCHELL (1981) The new species is also easily distinguished from any other species within the speciesgroup using the key to species of the E. antefurcalis species-group, partially modifi ed from GAULD &MITCHELL (1981) andGAULD (1982), as below: -UFMG) for their useful comments on the manuscript; to Kenichi Ikeda (Kobe University) for his kind support during the observation of specimens by using SEM at Kobe University; to Masahiro Ôhara (Hokkaido University Museum) for his kind support during the investigation of ichneumonid collection at SEHU; and Namiki Kikuchi (Hokkaido University) for his kind support at SEHU and offering the holotype specimen.