Barycnellus Khalaim & Ward, 2018

Khalaim, Andrey I. & Ward, Darren F., 2018, Tersilochinae (Hymenoptera: Ichneumonidae) from New Zealand. Part 1. Generic key and three new genera, Zootaxa 4425 (1), pp. 41-77 : 56

Genus Barycnellus Khalaim & Ward , gen. nov.

Type species: Barycnellus globosus Khalaim & Ward , sp. nov.

Diagnosis. Small species with body length 2.4–4.5 mm and fore wing length 2.0– 3.5 mm. Head weakly transverse in dorsal view; with occipital foramen clearly above centre and antennal insertion displaced downwards in lateral view. Clypeus very transversely lenticular, separated from face by sharp groove. Mandible slender, with upper tooth longer than lower tooth. Flagellum usually filiform, sometimes weakly tapered towards apex or slightly clavate, with 14–23 flagellomeres. Occipital carina complete. Hypostomal carina absent. Mesosoma from weakly to very strongly compressed laterally, weakly granulate to polished, without distinct punctures. Notauli weakly impressed, or completely absent. Foveate groove situated more or less in centre of mesopleuron, sometimes thin and rather sharp. Propodeum with more or less developed transverse carina and, sometimes with a pair of basal longitudinal carinae (often with these carinae absent and a shallow groove or rugose area present instead). Fore wing with 2m-cu vein antefurcal, except B. cuvierensis which has this vein distinctly postfurcal. Veins Rs and Rs+2 r meeting at obtuse angle (distinctly more 90°). Hind wing with vein cu1&cu-a strongly reclivous. Legs moderately slender to very robust; femora and tibiae sometimes thick and short while tarsus is unusually long. Metasoma with first tergite subcylindrical, with glymma situated just before the centre. Female with ovipositor slender to rather robust, short to moderately long (0.35 to 1.6× as long as hind tibia), with short dorsal subapical notch and abruptly thickened just behind this notch. Male with genital capsule large.

Comparison. Structurally Barycnellus resembles the genus Barycnemis Förster , where some species also have a globose head with eyes and insertions of antennae displaced downwards, elongate mesosoma, robust legs and abscissae of radius angled more than 90°.

Barycnellus is readily distinguished from other New Zealand genera by the following combination of features: fore wing with veins Rs and Rs+2 r angled at obtuse angle ( Figs 12–16 ); ovipositor with a step-like nodus on upper valve ( Figs 64 , 68 , 75 , 81 ); head subglobose, with foramen magnum very high, at or above level of upper margin of eye ( Figs 60, 63 , 66, 71 , 78 ); antennae inserted low down, at or below level of centre of eye ( Figs 60, 63 , 66, 71 , 78 ); mesosoma weakly to very strongly compressed laterally; clypeus strongly transverse; and male genital capsule unusually large ( Fig. 76 ).

Etymology. Named after the morphologically similar genus Barycnemis Förster. Gender masculine.

Remarks. Barycnellus is endemic to New Zealand and represented by five distinct species. Details of the biology of these species are unknown, but in the NZAC are 74 females and 1 male of one species, all similarly labelled which have apparently been reared from the larva of one elaterid ( Coleoptera : Elateridae ). This large brood suggests polyembryonic development.

Figures

FIGURES 10–15. Wings of Tersilochinae, females: 10—Aotearoazeus coronetus sp. nov.; 11—A. probles sp. nov.; 12— Barycnellus aucklandellus sp. nov.; 13—B. conlisus sp. nov.; 14—B. cuvierensis sp. nov.; 15—B. globosus sp. nov.

FIGURES 16–20. Wings of Tersilochinae, females: 16—Barycnellus robustus sp. nov.; 17—Gauldiana aspiringa sp. nov.; 18—G. minuta sp. nov.; 19—G. nigra sp. nov.; 20—G. triangulata sp. nov.

FIGURES 59–64. Barycnellus aucklandellus sp. nov., paratype, female: 59—head with antenna, front; 60—head, lateral. Barycnellus conlisus sp. nov., paratype, female: 61—head with antenna, lateral; 62—head and mesoscutum, dorsal; 63—head and mesosoma, lateral; 64—ovipositor, lateral.

FIGURES 65–71. Barycnellus cuvierensis sp. nov., paratype, female: 65—head with antenna, lateral; 66—anterior part of mesosoma and head, lateral; 67—head, dorsal; 68—ovipositor, lateral. Barycnellus globosus sp. nov., paratype, female: 69— anterior part of mesosoma and head with antennae, lateral; 70—mesoscutum and head, dorsal; 71—head, lateral.

FIGURES 72–79. Barycnellus globosus sp. nov., paratype, female (72–75) and male (76): 72—mesosoma and first tergite, lateral; 73—propodeum and base of metasoma, dorsolateral; 74—hind leg, lateral; 75—apex of metasoma with ovipositor, lateral; 76—metasoma. Barycnellus robustus sp. nov., paratype, female: 77—head and mesoscutum, dorsal; 78—head, lateral; 79—head with antenna, lateral.

FIGURES 80–87. Barycnellus robustus sp. nov., paratype, female: 80—hind leg, lateral; 81—apex of metasoma with ovipositor, lateral. Diaparsis zealandica sp. nov., paratype, female: 82—head with antenna, front; 83—head and mesoscutum, dorsal; 84—hind leg, lateral; 85—head and mesosoma, lateral; 86—propodeum, dorsal; 87—apex of ovipositor, lateral.