Corethrella (Corethrella) belkini Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 149-151

Corethrella (Corethrella) belkini Borkent , new species

DIAGNOSIS: Male and female adults: only extant species of Corethrella in the New World with the wing without dark scales just distal to the arculus, with dark scales in a subapical band (with no dark scales on these veins extending to the apex of the wing) (Figs. 64F, 70L), and with the hind femur with the basal half dark brown and apical half pale ( Fig. 53D).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig.12E). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna pale to light brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 23F, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus pale; segment 3 of nearly constant width, slight swollen subapically. Thorax (as in Fig. 53D): Dark brown, pale sclerites around base of wing. Posterior portion of dorsocentral row with group of about 7 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 antero- dorsal margin thick. Wing (Fig. 64F): 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, midlength, subapical band; veins (other than costa and wing margin) with well-developed scales. Halter pale. Legs (as in Fig. 53D): Forefemur dark brown; foretibia dark brown with apex darker; midfemur and tibia dark brown with very apex of midtibia darker; hind femur with basal half dark brown, apical half pale but with small patch of darker apicoventral pigmentation; hind tibia pale with basal and apical discrete 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. 79K): Medium brown, segment 9 dark brown. Genitalia (Fig. 94C): Gonocoxite medium brown, 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, tapering from base. Gonostylus (partially extended) nearly straight, gently curved near apex, slender, of more or less equal thickness for entire length but somewhat thicker apically, pointed apically; one elongate, slender subbasal seta, situated anteriorly or anteroventrally; apical seta slender, slightly elongate, simple. Aedeagus slender, elongate, tapering gradually to near apex, with slender apex, pointed apically, with lateral margins fused subapically or 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). Antennal flagellomeres as in Fig. 30J, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 18U) wide. Mandible with small, pointed teeth. Palpus as in Fig. 35A. Wing (Fig. 70L). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Medium brown, segment dark brown. Cercus dark brown.

Pupa. Mostly undescribed. Thorax: Scutum, metathorax each with spherical sensory pit (as in Fig. 100A). Respiratory organ (Fig. 102L): Tubular. Abdomen (Fig. 109A): 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 belkini is known from only from Puerto Rico (Fig. 122) at altitudes ranging from 660–1200 m. All 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 distinctive pigmentation pattern and were reared from the same habitat and larval and pupal types from three different localities in Puerto Rico.

Corethrella belkini adults are keyed twice because the subapical wing band is difficult to see in some specimens, partially through being rubbed but also because apparently in some the pigmentation is lighter. One female had dark subapical scales only along the costa and R 2 and in a few males the subapical band was also difficult to discern.

Two male paratypes from the road to El Yunque, Mameyes, Rio Grande, Puerto Rico, 900–1000 m, 3-IX- 1970 had the same “Mosquitoes of Middle America” number (PR164-22). There was an associated larval and pupal exuviae with the same number but it was uncertain to which male it belonged; this exuviae was excluded from the type series .

TYPES: Holotype, male adult on microscope slide, associated larval and pupal exuviae on separate slide, labeled " HOLOTYPE Corethrella belkini Borkent ", “km 21.9, Rt 184, Campamento Guavate, Cayey, Puerto Rico, 750 m, 5-IX-1970, M.J. Nelson”, “ Corethrella sp. 35 USNM”, “PR 169-31, Puerto Rico 70, Mosq. Mid. Amer.” (USNM). Allotype, female adult on microscope slide, associated larval and pupal exuviae on separate slide, labeled as for holotype ( USNM) . Paratypes: 2 ♂, 1 ♀ each with associated larval and pupal exuviae on separate slides, from type locality (1 ♂, 1 ♀, CNCI; 1 ♂, USNM) ; 3 ♂ and associated pupal exuviae on separate slides, 2 ♀ and associated larval and pupal exuviae on separate slides, from type locality but “PR-168" ( USNM) ; 2 ♂, Road to El Yunque, Mameyes, Rio Grande, Puerto Rico, 900–1000 m, 3-IX-1970 ( USNM) ; 1 ♂ with associated larval and pupal exuviae on separate slide, km 18.6, Rt 184, Campamento Guavate , Patillas, Puerto Rico, 800 m, 5-IX-1970 ( USNM) ; 1 ♂, 1 ♀, each with associated larval and pupal exuviae on separate slides, km 20.1, Rt 143, Toro Negro, Divisora, Jayuya / Ponce, Puerto Rico, 1200 m, 7-IX-1970 ( USNM) ; 3 ♂, 4 ♀, all but 1 ♀ with associated larval and pupal exuviae on separate slides, road to El Yunque about 250 m from Rt 191, Mameyes, Rio Grande, Puerto Rico, 660 m, 22-VIII-1970 ( USNM) ; 1 ♂, km 30.7, Rt 143, Toro Negro, Divisora, Orocovis, Puerto Rico, 900 m, 7-IX-1970 ( USNM) ; 1 ♀, with associated larval and pupal exuviae on separate slide, km 20.1, Rt 143, Toro Negro , Divisora, Jayuya / Ponce, Puerto Rico, 1200 m, 7-IX- 1970 ( USNM) ; 1 ♀, Road to El Yunque, Mameyes, Rio Grande, Puerto Rico, 900–1000 m, 3-IX-1970 ( USNM) .

DERIVATION OF SPECIFIC EPITHET: The name belkini is proposed to honor the memory of John N. Belkin, who contributed so much to our understanding of Culicoidea , including many species of Corethrella .