Corethrella (Corethrella) mckeeveri Colless, 1994

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 51-53

Corethrella (Corethrella) mckeeveri Colless

Corethrella mckeeveri Colless 1994:107 . Type locality: Hinchinbrook Island (Cayundah Ck.), Queensland, Australia. Holotype ♀ (ANIC).

DIAGNOSIS: Male and female adults: only extant species of Corethrella with the abdomen with a conspicuous pattern of subcutaneous, dense, dark pigmentation granules (Fig. 76D). Also the females are the only species in which the mandibles are completely smooth. Also the only Australian species with the face of the clypeus bearing 3–7 setae ( Fig. 17G) (others with 11 or more).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view unknown (specimens distorted). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna with basal 1/3 of flagellomere more darkly pigmented, remainder pale or light brown; pedicel without distinctive, more elongate, stout, dorsal or dorsolateral setae; flagellomeres as in Fig. 19D, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus likely pale or light brown; segment 3 swollen apically. Thorax (as in Fig. 38C): specimens in poor condition, appearing completely light brown but could have especially some pattern on pleura (not discernible). Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. Prescutal suture elongate, thick, uninterrupted, extending to near 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 not thick. Wing (Fig. 61D): Apex of R 2 equal to apex of M 1. With midlength, subapical band, at least veins M, CuA with dark scales subbasally (perhaps subbasal band present); veins (other than wing margin) with well-developed scales. Halter paler than scutellum. Legs (as in Fig. 38C): Light to medium brown, hind tibia with basal and apical darker, nondiscrete pigmentation. With only slender setae, lacking scales (except for some in patch of whip-like setae on posterior portion of hind tibia). Midleg with thick, subapical setae on each of at least tarsomeres 1–3. Apices of fore-, midleg fifth tarsomeres undivided, with claws slightly subapical to apical (as in Fig. 75D). Claws of fore-, midleg equal in length, longer than those of hind leg. Each claw without inner tooth. Anterior claws of each leg without a basal prong. Foreleg claws unequal. Midleg claws unequal. Foreleg third tarsomere longer than fourth tarsomere. Empodia slender. Abdomen (Fig. 76D): Uniformly light brown (possibly artificial, see below) but with conspicuous pattern of subcutaneous, dense, dark pigmentation granules. Genitalia (Fig. 83C): Gonocoxite likely uniformly pale, parallel-sided for most of length; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with setae of similar thickness as some other setae on gonocoxite, with basal setae of row slightly thinner than more apical setae, with row curving posteromedially with posteriormost seta of row positioned dorsomedially. With one dorsomedial stout seta, tapering from base. Gonostylus (in retracted position) straight, curved subapically, thick, of more or less equal thickness for entire length, tapered apically; one elongate, thick subbasal seta, situated ventrally; with thick, blunt apical peg. Aedeagus slender, elongate, tapering gradually to apex, pointed apically, with lateral margins separate apically.

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 uniformly light brown; flagellomeres as in Fig. 26A, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 17G) squarish. Mandible without teeth. Palpus as in Fig. 33G. Wing (Fig. 66G). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth).

Immatures. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella mckeeveri is known only from the type locality in Queensland, Australia (Fig. 116A) and were collected with a light trap in the tidal zone. The reduced female mouthparts ( McKeever and Colless 1991) indicate that this species is autogenous .

TAXONOMIC DISCUSSION: Males and females were associated through their shared pigmentation pattern and were collected together at the type locality. The paratypes I examined, all on microscope slides, were not labeled as such and labels were added to each (some on the back of the microscope slide). Colless (1994) pointed out that the specimens were partially bleached by storage in alcohol. Therefore, the descrip- tion of the pigmentation of the adults of this species is somewhat uncertain and there is a need to collect fresh material from the type locality.

Colless (1994) suggested that no other Australian species had subbasal pigmentation on the hind tibia but in fact it is present in at least some specimens of C. collessi , and the very base of the hind tibia is pigmented in C. marksae . Furthermore, Colless (1994) suggested that the wing pigmentation pattern of C. mckeeveri (Fig. 66G) is unique among Australian and possibly worldwide Corethrella . I consider it prudent to wait for further, unbleached specimens before further analysis but it appears true that the presence of a subapical wing band is indeed unique among Australian species. The wing pattern is similar to those of a group of Neotropical species with a clear subapical band ( quadrivittata species group; Figs. 70L–71B). The reduced mouthparts of the female of C. mckeeveri were described in detail by McKeever and Colless (1991) (as form from Hinchinbrook Island).

MATERIAL EXAMINED: Holotype, female adult on microscope slide (one wing on separate slide), labeled “ Holotype Corethrella mckeeveri Colless ANIC 6137, Aust. Nat. Ins. Coll.”, “Hinchinbrook Is (Cayundah Ck), Q., 8–17 Nov. 1984, E.N. Marks, Light, Tidal zone. Wing on slide 62", “ANIC Database No. 29 015086"; separate slide with wing labeled “W62", “ Holotype Corethrella mckeeveri Colless Wing, ANIC no. 29 015086, Aust. Nat. Ins. Coll.” ( ANIC). Paratypes: 6 ♂, 4 ♀ from type locality ( ANIC) .

DERIVATION OF SPECIFIC EPITHET: The name mckeeveri was proposed in recognition of the late Sturgis McKeever, who contributed so much to our understanding of Corethrellidae .