Corethrella (Corethrella) condita Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 177-178

Corethrella (Corethrella) condita Borkent , new species

DIAGNOSIS: Male adult: only extant species of Corethrella in the New World with the clypeus nearly square (as in Fig. 18 AG), a distinct midlength wing band, apex of R 2 with dark scales, margin of wing distal to midlength band with discrete dark portions (Fig. 65D), thorax dark brown (as in Fig. 56D), halter pale and lighter than scutellum, midfemur dark brown and equal to that of base of hind femur, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur), tarsomeres all uniformly pigmented (no bands) (as in Fig. 56D), midfemur without scales, abdominal segments 8 and 9 and gonocoxite uniformly dark brown (Fig. 80K) and gonostylus with the subbasal seta elongate (Fig. 97C). Female adult: not distinguishable from C. brakeleyi ; otherwise only extant species of Corethrella in the New World with the clypeus nearly square ( Fig. 18 AG), flagellomeres 2 and 3 elongate ( Fig. 31J), a distinct midlength wing band, margin of wing distal to midlength band with discrete dark portions (Fig. 71J), thorax dark brown ( Fig. 56D), halter pale and lighter than scutellum, midfemur dark brown and equal to that of base of hind femur, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur) ( Fig. 56D), and midfemur without scales.

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 13H). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna medium brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 24G, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus medium brown; segment 3 of nearly constant width. Thorax (as in Fig. 56D): Dark brown, pale sclerites around base of wing. Posterior portion of dorsocentral row with group of about 6 elongate setae. Prescutal suture short, not extending more than half way to dorsocentral row of setae. Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Ventral portion of posterior anepisternum triangular, uniformly brown, with anterodorsal margin thick. Wing (Fig. 65D): Apex of R 2 basal to apex of M 1. Anterior margin with differently, discretely pigmented scales (indicating anterior margins of wing bands), with subbasal band with dark scales extending posteriorly to margin, varying to some with CuA with pale scales, distinct midlength band present, dark scales on apex of R 2, some with dark scales on apices of R 3, R 4+5; veins (other than costa and wing margin) with well-developed scales. Halter pale. Legs (as in Fig. 56D): Medium to dark brown, with fore-, midleg knees pale, fore-, midtibiae lighter at midlength, hind femur with apical 0.2–0.4 pale, hind tibia pale with basal and apical nondiscrete dark brown pigmentation. With only slender setae, lacking scales (except for some in patch of whiplike setae on posterior portion of hind tibia). Midleg with thick, subapical setae on each of at least tarsomeres 1-3. Claw of foreleg longer than those of mid-, hind leg. Each claw without inner tooth. Anterior claws of each leg without a basal prong. Foreleg claws unequal. Midleg claws equal. Foreleg third tarsomere shorter than fourth tarsomere. Empodia slender. Abdomen (Fig. 80K): Medium brown. Genitalia (Fig. 97C): Gonocoxite dark brown, strongly tapering; anteromedial area with spicules similar in length to those else- where on gonocoxite; with well-defined dorsal row of setae, with setae 1–3 thicker than others; setae 1-3 curved at midlength; with row restricted to dorsal portion of gonocoxite. With one dorsomedial stout seta, tapering from base. Gonostylus (partially extended) slightly curved for basal half, more curved for apical half tapering near midlength, somewhat pointed apically; one elongate, slender, subbasal seta, situated anteriorly or anteroventrally; apical seta slender, short, simple. Aedeagus slender, elongate, tapering gradually to apex, pointed apically, with lateral margins fused near apex.

Female adult. Descriptive statistics: see Tables 6-11. As for male, with following differences. Head: Coronal suture elongate, extending ventrally past ommatida (as in Fig. 16B). Antenna; with flagellomeres as in Fig. 31J, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 18 AG) squarish. Mandible with small, pointed teeth. Palpus as in Fig. 35M. Wing (Fig. 71J). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Medium brown with segments 8-9 dark brown. Cercus dark brown.

Immatures. Unknown (but see taxonomic discussion below).

DISTRIBUTION AND BIONOMICS: Corethrella condita is known from Maryland, Delaware, North Carolina and Mississippi in the USA (Fig. 117A) at altitudes ranging from 2- 959 m. Specimens have been collected using a light trap and the holotype had a label with “larvae around base of Carex plants”. Because the females and immature stages of C. brakeleyi and C. condita cannot yet be distinguished, some or all of the features of the bionomics of C. brakeleyi given above may actually be those of C. condita .

TAXONOMIC DISCUSSION: Males and and the single female were tentatively associated, primarily based on the presence of both one male and one female collected from Delaware (but not from the exact same locality and date). It may well be that this female is actually a female C. brakeleyi . Conversely, some females described above as C. brakeleyi may actually be members of C. condita . Aside from differences mentioned in the keys, male C. condita differ from C. brakeleyi in lacking any subapical expansion of dorsal row setae 1- 3 on the gonocoxite.

TYPES: Holotype, male adult on microscope slide, labeled " HOLOTYPE Corethrella condita Borkent ”, “ Delaware, Lewes Fort Miles Naval Base , 1 May, RW Lake”, “ Corethrella brakeleyi USNM ”, “larvae around base of Carex plants”, “CO 15” ( USNM) . Allotype, female adult on microscope slide, labeled “ ALLOTYPE Corethrella condita Borkent ”, “ Delaware, Trap Pond St. Pk., 6 April 1963, F.J. Murphey ”, “ Corethrella brakeleyi USNM ”, “base of cypress trees”, “CO 13” ( USNM) . Paratypes: 1 ♂, Elk Neck State Park , Maryland, USA, 6-V-1960 ( CNCI) ; 1 ♂, Sapphire , Transylvania, North Carolina, USA, 20-VII-1990 ( USNM) ; 1 ♂, Harmon , Mississippi, USA, 22-V-1915 ( USNM) .

DERIVATION OF SPECIFIC EPITHET: The name condita (hidden) refers to the previously unrecognized presence of this species in the eastern United States.