Culicoides

Bellis, Glenn, Dyce, Alan, Gopurenko, David, Yanase, Tohru, Garros, Claire, Labuschagne, Karien & Mitchell, Andrew, 2014, Revision of the Culicoides (Avaritia) Imicola complex Khamala & Kettle (Diptera: Ceratopogonidae) from the Australasian region, Zootaxa 3768 (4), pp. 401-427 : 404-405

Culicoides subgen. Avaritia Fox, 1955: 218.

Type species Ceratopogon obsoletus Meigen , by original designation.

Imicola Complex Khamala & Kettle 1971:8.

Nominate species: Culicoides imicola Kieffer 1913: 11 .

Diagnosis (modified from Meiswinkel 2004). Adults: Females: the only species grouping within C. subg. Avaritia with terga on abdominal segments III–V almost round, not wider than long and with sclerotised plates surrounding gonopore truncate, not partially encircling the gonopore. Males: The only species grouping within C. subg. Avaritia with an asymmetrical apex to the anterior ‘peg’ of the aedeagus and with a single STl on antennal flagellomeres 5– 7 coupled with an absence of STl on flagellomere 8.

Description. Adults: Eyes bare. Palpus with five segments, each supporting SCh, segment 3 slightly swollen medially with a round, shallow pit (sensory area reduced to a depression in most specimens of C. nudipalpis ). Wing relatively strongly patterned. Mesonotum inconspicuously patterned, legs weakly banded, hind tibial comb with five spines, first from spur longest. Wing with cells r1 and r2 subequal in length, cell r2 tip included in post-stigmatal pale spot to varying degrees, lumens not expansive; pale markings large, distributed in all cells.

Female. Eyes contiguous for 1–2 facets. Antennae with basal flagellomeres barrel-shaped, distal flagellomeres elongate; SCo distribution 1, 10–13, in some species also present on 9; basal whorls of two to four SCh on 2–8 with higher numbers on flagellomeres 2, 4, 6 and 8 than on 3, 5 or 7, SCh always absent from 9–13; one pair of STl and one STc present on flagellomeres 2–8. Mouthparts relatively short, cibarium bare. Pigmentation on third and fourth abdominal tegites not markedly wider than long; sclerotised plate surrounding gonopore truncate; two subequal ovoid or round developed spermathecae with short, tapered necks and one vestigial present, sclerotized ring parallel-sided.

Male. Antennae with plume of SCh on flagellomeres 1–10, flagellomeres 2–10 partially fused, 11–13 elongate and subcylindrical; SCo distribution 1, 11–13; pair of STl on flagellomeres 2–4, single on 5–7; single STc on 2–8; basal whorls of three and two SCh on 11 and 12 respectively. Wings patterned similarly to female but with pale spots generally more expansive. Genitalia with ninth tergite as wide anteriorly as posteriorly with lateral sides concave, apicolateral processes reduced to broad flanges, posterior margin entire and concave. Gonocoxite almost parallel sided for most of its length, ventral and dorsal roots long and narrow, both curving to converge apically; dorsal root arising from gonocoxite at about 75–90°• Gonostylus slender, distally curving gently to a pointed apex. Ninth sternite with deep caudomedial excavation, membrane bare or spiculate. Aedeagus with low arch; body with almost straight lateral shoulders leading to a tapered distal process with a smoothly rounded apex; anteriorly projected peg not connected to arms of aedeagus by membrane and with an asymmetrically shaped apex. Parameres separate, converging and swelling medially, apical arms tapered, curved and converging to sharp tips.

Immatures: Pupa relatively smooth, respiratory horns stout without spines or transverse convolutions, lateral respiratory openings not borne on protuberances; Operculum with long hairlike spines, rarely with reticulate bulges; ad setae long, subequal; d tubercles 1–3 in line and 1 and 2 quite close together; caudal segment with a transverse band of spines across disc; caudal spines short, without spicules.

Larva with small eyes made up of a single pigmented spot on each side; head very short and square, broad in front; collar weakly developed. Ventral side of head with longitudinal suture, head setae moderately long; parahypostomal setae located at a distance from subgenal rim; labrum pointed, with two overlying folds; epipharynx with 2–3 combs, dorsal comb with 7–10 teeth. Thorax unpigmented but with diffuse paired post lateral patches of fat body in fourth instar.

Larval habitat: Animal dung-pats, moist turf high in organic matter, rotting organic matter. Larvae and pupae are unable to swim and sink in tap water.

World distribution. Restricted to the Old world - Afrotropical, Oriental, Palaearctic and Australasian regions.