Exochus acostulatus Lee & Choi 2016, sp. nov.
Creators: name: Choi, Jin-Kyung
name: Kolarov, Janko
name: Lee, Jong-Wook
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Exochus
Exochus acostulatus

description: Exochus acostulatus Lee & Choi sp. nov.
(Figures 1a, 3a, 6a)
Specimens examined
Holotype: female, type depository: YNU; (South Korea) GW, Donghae-si, Samhwa-dong, Mureung valley (M. T.), 31 May – 15 June 2005, leg. J.W. Lee; Paratype: type depository: YNU; 1 female, (South Korea) GB, Uljin-gun, Sangsa-ri, 24 May 1989, J.G. Kim.
Description
Female. Forewing 4.3 mm, body about 5.8 mm long.
Colour. Black. Upper margin of face, two spots between top of eyes and lateral ocelli, a spot on front half of tegula and palpi yellowish; legs orange reddish, tibiae basally orange yellow; flagellum brown ventrally.
Head. Rather transverse and narrowed behind eyes. Temple shorter than transverse diameter of eye (13: 20). Ocelli small, its diameter 0.7 times distance between lateral ocellus and eye. Frons smooth, with deep V-shaped groove behind base of antennae. Antenna with 30 flagellomeres. First flagellomere 2.0 times as long as wide. Apical half of flagellum with transverse segments. Face almost square, coarsely and densely punctate, distance between punctures less than their diameter. Clypeus not separated from face, weakly concave. Mandible tapered apically. Upper tooth much longer than lower tooth. Malar space 0.75 times as long as basal width of mandible. Occipital carina present only laterally, hypostomal carina rather strong, almost lamelliform.
Mesosoma. Epomia strong, notaulus short but deep. Mesopleuron moderately coarsely and densely punctate, distance between punctures longer than their diameter. Pro- and metapleuron smooth and lustrous, without punctures or setae. Epicnemial carina reaching subtegular ridge. Vein Rs originating from apical half of pterostigma. Vein Rs+M rather strongly curved. Vein Cu-a postfurcal of about 0.3 of its length. Vein cu-a of hindwing weakly inclivous, intercepted in lower third, vein 3Cu not pigmented, but distinct. Hindwing with eight distal hamuli. Legs moderately stout, hind femur 2.4 times as long as wide. Ratio between length of hind tarsal segments 30: 12: 10: 7: 13. Front spur of mid tibia less than half length of hind spur. Tarsal claws simple. Propodeum without costula. Area basalis not separated from area superomedia by carina. Combined area basalis and superomedia parallel. Area dentipara bare, with some setae in hind outer angle. Propodeal spiracle 2.0 times as long as wide, closer to pleural, than to lateral longitudinal carina.
Metasoma. With fine punctures, more distinct on basal tergites. Median longitudinal carinae extending 0.6 length of tergite 1. Epipleuron of tergite 3 wedge-shaped, basal two-thirds of edge straight. Ovipositor sheath not surpassing tip of metasoma.
Male. Unknown.
Etymology
From the absence of the costula on the propodeum.
Distribution
South Korea.
Remarks
The species is close to Exochus convergens Kusigemati, 1971, but differs by its longer malar space, the presence of the occipital carina laterally, yellow spots between the tops of the eyes and lateral ocelli, longer flagellum, bare area dentipara of propodeum, elongate propodeal spiracles, weakly inclivous vein cu-a of hindwing, and in coloration.
description: Published as part of Choi, Jin-Kyung, Kolarov, Janko & Lee, Jong-Wook, 2016, A taxonomic review of the genus Exochus Gravenhorst (Hymenoptera: Ichneumonidae: Metopiinae) from South Korea with descriptions of ten new species, pp. 2327-2367 in Journal of Natural History 50 on pages 2329-2331, DOI: 10.1080/00222933.2016.1197335, http://zenodo.org/record/3993034