Gilen,

Reshchikov, Alexey & Achterberg, Cornelis Van, 2018, The Unicorn exists! A remarkable new genus and species of Perilissini (Hymenoptera: Ichneumonidae) from South East Asia, Acta Entomologica Musei Nationalis Pragae 58 (2), pp. 523-529: 524

publication ID

http://doi.org/ 10.2478/aemnp-2018-0041

publication LSID

lsid:zoobank.org:pub:7E90FB36-ACAD-45C2-9194-E1AC57C45691

DOI

http://doi.org/10.5281/zenodo.4548706

persistent identifier

http://treatment.plazi.org/id/2D47A362-1973-3769-FE8A-FDFBFA0290D2

treatment provided by

Felipe

scientific name

Gilen
status

gen. nov.

Gilen  gen. nov.

Type species. Gilen orientalis  sp. nov. by present designation.

Diagnosis. Gilen  can be distinguished from other genera of Perilissini  by the following combination of character states: produced mid-longitudinal facial projection ( Figs 1A, 1BView Fig, 2AView Fig); lower mandibular tooth much longer than upper ( Fig. 1BView Fig); occipital carina incomplete dorsally ( Fig. 2BView Fig), and joined with hypostomal carina at base of mandible ( Fig. 2DView Fig); occiput with distinct concavity ( Fig. 2BView Fig); T1‒3 with slight transverse impressions ( Fig. 1EView Fig); last visible sternites in male with hind margins concave ( Fig. 2EView Fig).

The strong mid-longitudinal facial projection of Gilen  is a unique character in the Ichneumonidae  . The occipital carina joined with hypostomal carina at base of mandible ( Fig. 2DView Fig), hind wing with cu-a receiving Cu1 far below middle, and concave hind margins of last visible sternites in male ( Fig. 2EView Fig) are characters shared with Lathrolestes Förster, 1869  , Neurogenia Roman, 2010  and Priopoda Holmgren, 1856  . It is therefore assumed that these genera are most likely closely related to Gilen  .

Description. Fore wing length 6.8–7.0 mm.

Head. Clypeus flat in lateral view ( Figs 1AView Fig, 2AView Fig), its lower margin blunt and more or less bulging apically ( Fig. 1BView Fig). Face (in anterior view) with goblet-shaped mid-longitudinal projection ( Figs 1A, 1BView Fig, 2AView Fig), and rather sparsely setose ( Fig. 1BView Fig). Anterior tentorial pit rather large ( Fig. 1BView Fig). Eyes bare ( Figs 1BView Fig, 2AView Fig). Lower mandibular tooth much longer than upper ( Fig. 1BView Fig). Occipital carina incomplete dorsally ( Fig. 2BView Fig), ventrally joined with hypostomal carina at base of mandible ( Fig. 2DView Fig). Occiput with distinct concavity ( Fig. 2BView Fig).

Mesosoma. Epomia absent ( Fig. 2CView Fig). Notauli very shallow and indistinct ( Fig. 2BView Fig). Mesopleuron with sternaulus-like impression ( Fig. 2CView Fig). Epicnemial carina distant from anterior margin of mesopleuron (2C). Propodeum in lateral profile convexly rounded ( Fig. 1AView Fig), with carinae complete except for area basalis, which is absent (fused with area superomedia) ( Fig. 1CView Fig). Forewing with areolet petiolate ( Fig. 1AView Fig). Pterostigma receiving vein Rs+2r at its basal 0.35. Vein 2m-cu with a single bulla. Hind wing with cu-a receiving Cu1 well below middle. Tarsal claws strongly pectinate ( Fig. 1DView Fig). Fore tibia with apical tooth.

Metasoma distinctly and densely punctate, sparsely setose. T1 as long as broad with dorsal longitudinal carina defined. Glymma deep. T1‒3 with slight transverse impression. Ovipositor sheath flat, not longer than depth of metasomal apex. Ovipositor straight, with a long, shallow, subapical dorsal notch. Last visible sternites in male with hind margin concave ( Fig. 2EView Fig). Parameres broad and short ( Fig. 2EView Fig).

Differential diagnosis. See Key and Discussion below.

Etymology. The generic name ʻ Gilen  ʼ refers to a mythical single horned creature (Thai name: กเลน) known in Thai and other Asian cultures. It refers to the unique mid-longitudinal facial projection. The gender is masculine.

Species included. The genus is described as monotypic.

Partial key to the genera of the tribe Perilissini 

This key enables identification of genera with hypostomal carina separated from occipital carina ventrally or joining occipital carina at base of mandible

1 Produced mid-longitudinal facial projection present ( Figs 1A, 1BView Fig, 2AView Fig). T1‒3 with slight transverse impression. ....................................... Gilen  gen. nov.

– Face without mid-longitudinal projection. T1‒3 without slight transverse impression........................ 2

2 Vein M+Cu of fore wing with tubercle or spur. Male parameres usually very long and narrow. ................... .......................................... Neurogenia Roman, 1910 

– Vein M+Cu of fore wing without tubercle or spur. Male parameres usually not narrow. ....................... 3

3 T 1 in female approximately twice as long as broad. Apical margin of last visible sternite in male with one or several notches. Male parameres broadly triangular. Aedeagus reflexed and pointed apically, with adzelike blade. ....................... Priopoda Holmgren, 1856 

– T 1 in female less than twice as long as broad. Apical margin of last visible sternite in male without notches. Male parameres mostly broadly rounded or rectangular in dorsal view. Aedeagus rounded and clubbed distally, without adze-like blade. .................. ......................................... Lathrolestes Förster, 1869