Corethrella (Corethrella) grandipalpis Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 62

Corethrella (Corethrella) grandipalpis Borkent , new species

DIAGNOSIS: Male adult: unknown. Female adult: only extant species of Corethrella in the New World with a circular head (in anterior view) ( Fig. 7A), with flagellomere 1 moderately elongate ( Fig. 26H), wing with apex of R 2 slightly distal to apex of M 1 (Fig. 67C) and veins with only setae (Fig. 73C), with uniformly pigmented wing (Fig. 67C), scutum, katepisternum (with or without a very narrow dorsal pale band) ( Fig. 40C), and legs ( Fig. 40C).

DESCRIPTION: Male adult. Unknown.

Female adult. Descriptive statistics: see Tables 6–11. Head: Outline in anterior view nearly circular ( Fig. 7A). Coronal suture absent (as in Fig. 16C). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16C). Antenna uniformly brown; pedicel with slightly developed more elongate, stout, dorsal or dorsolateral setae; flagellomeres as in Fig. 26H, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Clypeus ( Fig. 17L) squarish. Mandible with small, pointed teeth. Palpus ( Fig. 33N) brown; segment 3 swollen apically. Thorax ( Fig. 40C): nearly uniformly brown, posterior portion of posterior anepisternum pale, pale sclerites around base of wing. Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. Prescutal suture elongate, interrupted by area of pale cuticle. Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Ventral portion of posterior anepisternum not differentiated from dorsal portion, anterior margin more darkly pigmented than posterior margin. Wing (Fig. 67C): Apex of R 2 slightly distal to apex of M 1. Plain, without pattern of pigmented veins and/or scales; veins (other than wing margin) with very slender scales. Halter nearly as dark as scutellum. Legs ( Fig. 40C): Uniformly medium brown, with basal 0.25 of hind femur somewhat lighter. 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. Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Empodia slender. Abdomen: uniformly pigmented brown.

Immatures. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella grandipalpis is known only from Carara National Park on the west coast of Costa Rica (Fig. 121B) at an altitude of 20 m. All three females were collected with a frog-call trap close to the Tárcoles River. The serrate mandibles of the female adults and their attraction to Hyla gratiosa calls suggest that they feed on frog blood in nature .

TYPES: Holotype, female adult on microscope slide, labeled " HOLOTYPE Corethrella grandipalpis Borkent , female adult on microscope slide, labeled “ 5 km NE Tárcoles , C.R., 2-IX-1993, CD1568" ( CNCI) . Paratypes: 5 ♀ from type locality, 20 m, but 20-VII-1993 (3 ♀, CNCI; 1 ♀, USNM; 1 ♀, ANIC); 1 ♀ from type locality, but 17-VIII-1993 ( INBC) .

DERIVATION OF SPECIFIC EPITHET: The name grandipalpis (large, palpus) refers to the apically swollen third palpal segment of females of this species (and numbers of others).