Corethrella (Corethrella) guadeloupensis Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 119-121

Corethrella (Corethrella) guadeloupensis Borkent , new species

DIAGNOSIS: Male adult: only extant species of Corethrella in the New World with a distinct midlength wing band (Fig. 63H), thorax medium to dark brown (as in Fig. 49D), midfemur dark brown and equal to that of base of hind femur, midfemur without scales, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur) and both basal and apical dark brown pigmentation discrete (as in Fig. 49D), segment 8 pale and contrasting against light brown segment 7 and dark brown segment 9, base of gonocoxite and segment nine equally dark brown, gonocoxite lightening apically (Fig. 78K), gonocoxite short and squat, and aedeagus apex pointed (Fig. 91C). Female adult: only extant species of Corethrella in the New World with the clypeus wider than long ( Fig. 18E), flagellomeres 1–3 each moderately elongate ( Fig. 29F), flagellomere 3 without sensilla coeloconica, flagellomere 12 with one sensillum coeloconicum, a distinct midlength wing band extending continuously from anterior to posterior margin of wing (dark scales present on all veins), with more basal darker scales on C, Sc and A, and without any dark scales distal to the midlength band (including the margin of the wing) (Fig. 69J), thorax dark brown ( Fig. 49D), halter pale (lighter than scutellum), midfemur dark brown and equal to that of base of hind femur, midfemur without scales, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur) and tarsomere 2–4 of mid- and hind leg banded ( Fig. 49D).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 10G). Four large setae on frons between ventromedial area of ommatida (as in Fig. 16G). Antenna light brown, with flagellomeres 10–13 slightly darker; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 22E, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus pale; segment 3 of nearly constant width, slightly swollen at midlength. Thorax (as in Fig. 49D): Medium or dark brown, pale sclerites around base of wing, scutellum with darker anteromedial spot. Posterior portion of dorsocentral row with group of about 4 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. 63H): 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; slight darkening of scales just distal to arculus; veins (other than costa and wing margin) with well-developed scales Halter pale, paler than scutellum. Legs (as in Fig. 49D): Medium or dark brown with apical 1/4 of forefemur somewhat lighter, very base of foretibia lighter, basal third of midtibia slightly lighter, hind femur with apical 0.6 pale, hind tibia with discrete basal and apical dark brown pigmentation, 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. 78K): Light brown, with sternites 1–2 slightly darker, segment 8 pale, segment 9 medium brown. Genitalia (Fig. 91C): Gonocoxite medium brown, lightening apically, strongly tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with setae 1, 2 thicker than others, 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 (partially extended) mostly straight, bent subapically, slender, of more or less equal thickness for entire length, somewhat expanded apically, apex rounded; one elongate, slender subbasal seta, situated anteriorly or anteroventrally; apical seta slender, elongate, bifurcating. Aedeagus slender, elongate, narrow, tapering gradually to apex, slightly rounded apically, with fusion of lateral margins uncertain.

Female adult. Descriptive statistics: see Tables 6–11. As for male, with following differences. Head: Coronal suture elongate, extending ventrally past ommatida ( Fig. 16G). Antenna dark brown; with flagellomeres as in Fig. 29F, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 18E) squarish. Mandible with moderately sized, pointed teeth. Palpus as in Fig. 34Q. Wing (Fig. 69J): as for male but with some basal slightly darker setae on C. Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Light brown, with sternites 1–2 slightly darker, segments 8–9 dark brown. Cercus light brown.

Pupa. Mostly undescribed. Thorax: Scutum, metathorax each with spherical sensory pit (as in Fig. 100A). Respiratory organ (Fig. 102D): Tubular. Abdomen (Fig. 107A): Segments 3–7 somewhat expanded laterally. Paddle only moderately elongate; apicodorsal thick spine articulating; apicoventral seta longer than thick spine.

Larva. Undescribed.

Egg. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella guadeloupensis is known only from the Caribbean islands of Montserrat and Guadeloupe (Fig. 135) at altitudes ranging from 350–900 m. Considering the devastating volcanic eruption on Montserrat in July, 1995, and the following pyroclastic mudflows which followed for 3 years, it is quite possible that the species no longer exists there. All adult specimens were reared from bromeliads. The specimens from the Belkin “Mosquitoes of Middle America” project are identified in Table 12.

TAXONOMIC DISCUSSION: Males and females were associated through the shared presence of a common pigmentation pattern and were reared together on Montserrat.

TYPES: Holotype, male adult on microscope slide, larval and pupal exuviae on separate slide, labeled " HOLOTYPE Corethrella guadeloupensis Borkent ”, “Baines Jaunes, St. Claude, Basse Terre, Guadeloupe, 900 m, 3-VII-1971, J.N. Belkin, bromeliads", “ Corethrella sp. 25. USNM”, “FWI 700-22, Fr West Indies Mosq Mid Amer” (USNM). Allotype, female adult on microscope slide, larval and pupal exuviae on separate slide, labeled “ Route des Deux Mamelles , Petit Bourg , Basse Terre, Guadeloupe, 500 m, 4-VII-1971, J.N. Belkin ”, “ Corethrella sp. 25”, “FWI 701-20, Fr West Indies Mosq Mid Amer ”“ ( USNM) . Paratypes: 1 ♂ with pupal exuviae, from type locality but FWI 700-20 ( USNM) ; 1 ♀ with larval and pupal exuviae, from allotype locality but FWI 701-21 ( USNM) ; 1 ♂, 1 ♀, both with larval and pupal exuviae, 2.5 km SE Galways Soufriere, South Soufriere Hills , St. Anthony, Montserrate, 350 m, 12-X-1966 ( USNM) ; 1 ♀, with larval and pupal exuviae, 0.8 km SE Galways Soufriere, South Soufriere Hills , St. Anthony, Montserrate, 500 m, 12-X-1966 ( CNCI) .

DERIVATION OF SPECIFIC EPITHET: The name guadeloupensis recognizes the type locality in Guadeloupe.