Corethrella (Corethrella) lepida Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 123-124

Corethrella (Corethrella) lepida Borkent , new species

DIAGNOSIS: Male adult: only extant species of Corethrella in the New World with a midlength wing band and no other bands on the wing (some darker scales more basally but not as a distinct subbasal band) (Fig. 63I), dark brown pleura (as in Fig. 50C), with the apical 0.25 of the midfemur, the apical half of the hind femur and basal 3/4 of the hind tibia equally pale (as in Fig. 50C), the abdomen entirely medium brown (sternites 1–2 not more darkly pigmented) (Fig. 78L), and with the gonocoxite nearly entirely light brown (somewhat darker at very base). Female adult: only extant species of Corethrella in the New World with flagellomeres 1–3 each elongate ( Fig. 29I), a midlength wing band and no other bands on the wing (some darker scales more basally along the costa and sc) (Fig. 69M), with dark brown pleura ( Fig. 50C), with the apical 0.14–0.25 of the midfemur more lightly pigmented, and the apical half of the hind femur and basal 2/3 of the hind tibia equally pale (some with slight, poorly defined pigmentation near base of hind tibia) ( Fig. 50C), the abdomen entirely dark brown (sternites 1–2 not more darkly pigmented).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 11A). Four large setae on frons between ventromedial area of ommatida (as in Fig. 16G). Antenna uniformly light brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 22F, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus pale; segment 3 of nearly constant width. Thorax (as in Fig. 50C): Scutum, scutellum, mediotergite light to medium brown, remainder of thorax dark brown, pale sclerites around base of wing, scutellum with slightly darker anteromedial spot. Posterior portion of dorsocentral row with group of about 5 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. 63I): Apex of R 2 basal to apex of M 1. Anterior margin with differently, discretely pigmented scales (indicating anterior margin of midlength band), with midlength band; veins (other than costa and wing margin) with well-developed scales. Halter pale. Legs (as in Fig. 50C): Dark brown with following pale or paler: apical 0.3 of forefemur, basal 0.25 of foretibia, apical 0.25 of midfemur, basal 0.2 of midtibia, apical half of hind femur, basal 0.6–0.7 of hind tibia, at least mid-, hind leg tarsomeres 2–4 with banding. 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. 75F). 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. 78L): Light brown, with segment 8 lighter, segment 9 medium brown. Genitalia (Fig. 91D): Gonocoxite light brown, slightly darker at very base, elongate, gently tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with seta 2 thickest, with row restricted to dorsal portion of gonocoxite. With one dorsomedial stout seta, more or less of even thickness for most of length, tapering near apex. Gonostylus (in retracted position) straight for most of length, curved for apical 1/4, slender, expanded subapically, tapered apically; one elongate, slender subbasal seta, situated anteriorly or anteroventrally; apical seta slender, elongate, simple. Aedeagus slender, elongate, tapering gradually to apex, pointed apically, with lateral margins fused subapically.

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. 16G). Antennal flagellomeres 1–4 light brown, flagellomere 5–13 progressively darker; with flagellomeres as in Fig. 29I, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 18H) wide. Mandible with small, pointed teeth. Palpus ( Fig. 34T) pale or light brown; segment 3 somewhat ovoid, swollen at or near midlength. Wing (Fig. 69M). Legs ( Fig. 50C): As for male but basal 0.14–0.25 of midtibia more lightly pigmented. Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Light to medium brown with segments 8–9 darker. Cercus medium brown.

Immatures. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella lepida is known from Costa Rica, Trinidad and Tobago, Guyana, and French Guiana (Fig. 127) at altitudes ranging from 5– 100 m. Specimens have been collected using frog-call, Malaise and light traps. The serrate mandibles of the female adults and their attraction to Hyla gratiosa calls suggest that they feed on frog blood in nature. At La Selva Biological Station in Costa Rica, female adult C. lepida were uncommon to moderately common in the frog-call traps (using Hyla gratiosa ), making up between 1–14% of the total Corethrella collected March 2, 2004 (total numbers in four samples: 41, 83, 148 and 170 specimens). This species was collected by G. Bourne in Guyana with the taped calls of Bufo typhonius and Scinax ruber (Laurenti) . The specimen from the Belkin “Mosquitoes of Middle America” project is listed in Table 12.

TAXONOMIC DISCUSSION: The male and females of this species are tentatively associated. The single male was collected about 30 km NW of La Selva. The geographical closest females were 12 females collected at La Selva. They shared a similar pigmentation pattern and were therefore considered to be conspecific.

The three females from Trinidad and Tobago were previously identified by Lane as C. lopesi but were not included by Lane and Aitken (1956) in their analysis of the Trinidadian fauna .

TYPES: Holotype, male adult on microscope slide, labeled " HOLOTYPE Corethrella lepida Borkent ", “ COSTA RICA. Prov. Alajuela, San Carlos, Boca Tapada, Laguna Lagarto Lodge, 50– 100 m. 23 JUN–23 JUL 2004. B. Hernandez, Malaise. LN 296095 516714 #77931”(INBC). Allotype, female adult on microscope slide, La Selva Biological Station , Costa Rica, 40 m, 1-III-2004 ( CNCI) . Paratypes: 11 ♀, labeled as for allotype (8 ♀, CNCI; 2 ♀, INBC; 1 USNM) ; 3 ♀, San Rafael , Trinidad and Tobago, 2–3-X-1955 ( USNM) ; 10 ♀, CEIBA Biological Center , 06°29 N, 58° 13 W, Guyana, 20-III-2006 ( CNCI) ; 2 ♀, Dubulay Ranch , Guyana, 05°,40’56’’ N, 57°, 51’29’’ W, 14-III-2006 ( CNCI) ; 1 ♀, 24 km SW Cayenne, Guyane , French Guiana, 5 m, 1–2-II-1965 ( USNM) .

DERIVATION OF SPECIFIC EPITHET: The name lepida (elegant) is proposed to reflect the rather pretty pigmentation of adults of this species.