Corethrella (Corethrella) truncata Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 84-85

Corethrella (Corethrella) truncata Borkent , new species

Corethrella (Lutzomiops) nigrescens , in part: Lane 1942:129.

Lutzomiops nigrescens , in part: Lane 1953:96.

DIAGNOSIS: Male adult: unknown. Female adult: only extant species of Corethrella in the New World with flagellomeres 1–4 short (with flagellomere 4 much shorter than flagellomere 5) ( Fig. 27H), a plain wing (Fig. 68B), uniformly light brown midfemur and hind tibia, and the scutum medium brown (with slight indication of pattern but not with lateral vittae darker) ( Fig. 44A).

DESCRIPTION: Male adult. Unknown.

Female adult. Descriptive statistics: see Tables 6–11. Head: Outline in anterior view laterally elongate ( Fig. 8C). Coronal suture elongate, extending ventrally past ommatida (as in Fig. 16D). Four large setae on frons between ventromedial area of ommatida (as in Fig. 16D). Antenna uniformly medium brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 27H, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Clypeus ( Fig. 17Y) squarish. Mandible with small, pointed teeth. Palpus ( Fig. 33 AA) brown; segment 3 somewhat ovoid. Thorax ( Fig. 44A): Uniformly medium brown, scutum with some mottling, pale sclerites around base of wing. Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. 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. 68B): Apex of R 2 equal to apex of M 1. Plain, without pattern of pigmented veins and/or scales; veins (other than costa and wing margin) with well-developed scales. Halter as dark as scutellum. Legs ( Fig. 44A): Uniformly pigmented but with about basal half (or more) of hind femur slightly pale (not discrete). Femora, tibiae with slender scales. Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Empodia slender. Abdomen: Uniformly medium brown.

Immatures. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella truncata is known only from the single holotype collected at Juquiá , São Paulo, Brazil (Fig. 130) at an altitude of 85 m. It is uncertain how it was collected .

TAXONOMIC DISCUSSION: The holotype of C. truncata was previously described as a paratype of C. nigrescens , which is considered here as a synonym of C. davisi . The distinctively truncated antennal flagellomeres 1–4 serve to distinguish it from C. davisi but otherwise the two species are very similar.

The holotype was labeled with two identification labels: C. nigrescens and C. nigra . Lane (1942: 129) indicated that the paratype of C. nigrescens came from Juquiá, São Paulo and this matches the locality label on the holotype of C. truncata . He further stated that it was collected in January, 1939 but the specimen at hand lacks a label with this information. The label on the holotype also identifying it as C. nigra is puzzling because Lane never recognized this as a locality for this species. Nor did he suggest that the two might be conspecific (as recognized in the current study).

The recognition of type material of C. davisi and its synonyms, C. nigrescens and C. nigra , is discussed further in the taxonomic discussion of C. davisi .

The holotype was originally on a pin but is now on a microscope slide. It is missing its left antenna, left hind leg and the thorax is somewhat crumpled.

TYPES: Holotype, female adult on microscope slide, labeled " HOLOTYPE Corethrella truncata Borkent ”, “ Corethrella nigrescens Lane, 1941 ”, “ Corethrella nigra Lane, 1939 ”, “paratipo”, “ S. Paulo, Juquiá, J. Lane col.”, “1.077”, “1.077”, “1.137”, “S100 T990” ( DEFS).

DERIVATION OF SPECIFIC EPITHET: The name truncata (shortened) refers to the reduced first four flagellomeres of the female antenna.