Corethrella (Corethrella) marksae Colless, 1986

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 46-48

Corethrella (Corethrella) marksae Colless

Corethrella marksae Colless 1986:33 . Type locality: Kangaroo Valley , New South Wales, Australia. Holotype ♂ (ANIC).

DIAGNOSIS: Male and female adults: only extant species of Corethrella in Australia with a wing with three distinct bands of pigmentation: one traversing the region of r-m, one at its apex and one between these two (over fork of R 2+3 and M 1+2), with the anterior margin of wing with distinct pale scales on either side of the anterior margin of the band over R 2+3 and M 1+2 (Figs. 61B, 66D) and with discrete, dark leg pigmentation subapically on each femur and tibia, which are otherwise pale ( Fig. 37D).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view somewhat circular (as in Fig.6C). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna uniformly medium brown; pedicel without distinctive, more elongate, stout, dorsal or dorsolateral setae; flagellomeres as in Fig. 19B, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus light brown; segment 3 swollen apically. Thorax (as in Fig. 37D): Medium to dark brown, with scutum, pleura mottled. Posterior portion of dorsocentral row with 3 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 larger than ventral portion. Ventral portion of posterior anepisternum triangular, uniformly brown, with anterodorsal margin not thick. Wing (Fig. 61B): Apex of R 2 equal to apex of M 1. Three distinct bands of pigmentation: one traversing region of r-m, one at its apex and one between these two (over fork of R 2+3 and M 1+2); veins (other than wing margin) with slender scales. Halter paler than scutellum. Legs (as in Fig. 37D): Light brown, with discrete, dark leg pigmentation subapically on each femur, tibia. With only slender setae, lacking scales (except for some in patch of whip-like setae on posterior portion of hind tibia). Midleg without thick, subapical setae on each of tarsomeres 1–3. Apices of fore-, midleg fifth tarsomeres undivided, with claws slightly subapical to apical (as in Fig. 75E). 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 more or less equal in length to fourth tarsomere. Empodia slender. Abdomen (Fig. 76B): Tergites 1–6, sternites 1–6 each with anterior dark brown band; segment 7–9 dark brown. Genitalia (Fig. 83B): Gonocoxite uniformly dark brown, gently tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with setae of increasing thickness anteriorly to posteriorly with 3 posteriormost setae equally thick, with row curving posteromedially with posteriormost seta of row positioned dorsomedially. With one dorsomedial stout seta, tapering from base. Gonostylus (in retracted position) straight, thick; of more or less equal thickness for entire length with slight narrowing at midlength, 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: flagellomeres as in Fig. 25J, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 17D) squarish. Mandible with small, pointed teeth. Palpus as in Fig. 33D. Wing (Fig. 66D). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Tergite 1 with dark pigmentation anterolaterally, tergites 2–6 each with anterior band of dark pigmentation; sternite 1 pale, sternite 2 entirely medium brown, sternites 3–6 with anterior band of dark pigmentation; segments 7–9 dark brown. Cercus medium brown.

Pupa. Unknown.

Larva. Not definitely associated; described by Colless (1986).

Egg. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella marksae is known from Queensland south to Victoria, Australia (Fig. 115B) at altitudes ranging from 0– 596 m. The localities of two paratypes, a female adult from Eungella National Park, Queensland and a larva from Moe-Walhalla Rd., Thomson River, Victoria, were not included in the distribution map because the adult was not examined (but see below) and the larva was of uncertain association (although likely correct, considering its distribution). Two female C. marksae were collected “on” a frog Mixophyes fleayi Corben and Ingram (Fleay's Barred Frog), a species of Myobatrachidae that have males with a loud, distinctive call during August to March ( O'Reilly and Hines 2002). The fact that both female C. marksae had distended abdomens and possess well-developed mouthparts indicates that they are blood-feeding. Mixophyes fleayi is restricted to the Conondale Range in SE Queensland south to Yabbra scrub in NE New South Wales, whereas C. marksae has a significantly broader distribution. Therefore, if C. marksae is anautogenous, it must feed on other frogs as well.

The tentatively associated larva was collected from “a small, pebbly back-water of a flowing river” ( Colless 1986). Male and female adults from an unnamed tributary of Bimberamal River were collected with a Malaise trap spanning the dry creek bed but near to small but deep (about 0.5 m) cracks in the stream bed (nearly a solid piece of rock) filled with standing water (J. Ogawa, pers. comm.).

TAXONOMIC DISCUSSION: Males and females were associated through the shared presence of a distinctive pigmentation pattern and the holotype male and one female paratype were collected at the same place and date. I examined all type material except for one female paratype from Eungella National Park in Queensland. Paratype labels were missing from all but one specimen and were therefore added to the specimens studied by Colless (1986), including the single larva .

I examined two females from Eungella National Park but these were previously labeled only as “ Corethrella sp. ”. It is possible that one of these was described by Colless (1986) as a member of C. marksae . I considered the specimens too bleached to identify.

Bugledich (1999:159) provided a habitus drawing of a female C. marksae which does not portray its pigmentation pattern.

MATERIAL EXAMINED: Holotype, adult male, pinned, with one wing on microscope slide, genitalia on separate slide, pinned portion labeled “ Holotype, Corethrella marksae Colless ANIC 6045", “Kangaroo Valley, N.S.W., 23-iii-1961, D.H. Colless”, “Terminalia slide T28", “Wing on slide 33", “ANIC database no. 29014-S14 + slide”, wing labeled “ Holotype, Corethrella marksae Colless , Wing of holotype ”, “ANIC database no. 29014”, genitalia labeled “ Holotype, Corethrella marksae Colless , genitalia of holotype ”, “T28" (scratched on glass) ( ANIC). Paratypes: 1 ♂, Minnamurra Falls , New South Wales, 16-XI-1960 ( ANIC) ; 2 ♂, 14 mi. N. Briagalong , Victoria, 22-III-1962 ( ANIC) ; 1 ♀, Upper Kangaroo Valley , New South Wales, 23-XI- 1960 ( ANIC) ; 1 male wing “W39" ( ANIC) . Other material: 2 ♀, Goomburra , Queensland, 1-II-1997 ( ANIC) ; 6 ♂, 4 ♀, unnamed tributary of Bimberamal River crossed by Mines Road, Bimberamala National Park , 18-20- X-2002 (5 ♂, 3 ♀, CNCI; 1 ♂, 1 ♀, USNM) ; 1 fourth instar larva, Moe-Walhalla Road, Thomson River, Victoria, 27-XI-1976 ( ANIC) .

DERIVATION OF SPECIFIC EPITHET: The name marksae was proposed by Colless (1986) for E.N. Marks.