Corethrella (Corethrella) davisi Shannon and Del Ponte, 1928

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 88-91

Corethrella (Corethrella) davisi Shannon and Del Ponte

Corethrella davisi Shannon and Del Ponte 1928:102 . Type locality: 5 km W. of Concepcion , Tucuman, Argentina. Lec-

totype ♀ designated by Casal in Belkin et al. 1968:17 (INMA). Lutzomiops davisi: Lane 1953:94 . Corethrella nigra Lane 1939a:105 . Type locality: Maracajú, Mato Grosso, Brazil. Holotype ♂ (DEFS). Corethrella (Lutzomiops) nigra: Lane 1942:127 . Lane 1951:333. Lutzomiops nigra: Belkin et al. 1971:29 . Corethrella (Lutzomiops) nigrescens Lane 1942:129 . Type locality: Magé, Rio de Janeiro, Brazil. Holotype ♀ (DEFS).

New synonym. Lutzomiops nigrescens: Lane 1953:96 .

DIAGNOSIS: Male adult: only extant species of Corethrella in the New World with a plain wing (Fig. 62G), scutum uniformly medium brown, katepisternum medium brown or medium brown with the dorsal margin pale, uniformly brown legs except for the hind femur with about the basal half (or more) pale, and with the trochanter of foreleg brown, equal to that of base of forefemur (as in Fig. 44D). Female adult: only extant species of Corethrella in the New World with head elongated laterally ( Fig. 8F), flagellomeres 1 and 2 each moderately to very elongate ( Fig. 27K), a plain wing (Fig. 68E), scutum uniformly medium brown, katepisternum medium brown or medium brown with the dorsal margin pale, anepimeron light to dark brown ( Fig. 44D), uniformly brown legs except for the hind femur with about the basal half (or more) pale, and with the trochanter of foreleg brown, equal to that of base of forefemur ( Fig. 44D).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 8F). Four large setae on frons between ventromedial area of ommatida (as in Fig. 16D). Antenna uniformly brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 21A, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus brown; segment 3 of constant width. Thorax (as in Fig. 44D): uniformly medium brown but in some with dorsal margin or posterior margin of katepisternum pale, anepimeron light to medium brown, 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. 62G): Apex of R 2 basal 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 or darker than scutellum. Legs (Fig. as in Fig. 44D): Uniformly pigmented but with about basal half (or more) of hind femur slightly pale (not discrete). Femora, tibiae with slender scales (also 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 bilobed in dorsoventral view, with claws subapical (as in Fig. 75E). Elongate claw of foreleg shorter than that of midleg, both longer than those of hind leg. Each claw without inner tooth. Anterior claws of each leg without a basal prong. Foreleg claws unequal. Midleg claws unequal. Foreleg third tarsomere longer than fourth tarsomere. Empodia slender. Abdomen (Fig. 77H): Segments 1–7 light to medium brown, segment 8–9 light to medium brown (in some lighter brown than segment 7), segment 9 pale to medium brown, in some partially brown. Genitalia (Fig. 88A): Gonocoxite uniformly pale to medium brown, strongly tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with 2–3 basal setae of row stout, enlarged and bent subapically, 2 more posterior setae slender, with row restricted to dorsal portion of gonocoxite. With two dorsomedial stout setae, tapering from base, anterior seta more stout, bases joined by sclerotized plate. Gonostylus (in retracted position) straight to slightly curved, thick, with basal half more slender or entire gonostylus of nearly constant diameter, rounded apically; one elongate, thick subbasal seta, situated posteroventrally; apical seta slender, elongate, simple. Aedeagus squat, somewhat triangular, tapering gradually to apex, pointed apically, with lateral margins fused at 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. 16D). Antenna; with flagellomeres as in Fig. 27K, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 17 AB) squarish. Mandible with small, pointed teeth. Palpus as in Fig. AD. Wing (Fig. 68E). Legs: Apices of fore-, midleg fifth tarsomeres undivided, with claws situated slightly subapically to apically. Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Uniformly medium brown.

Pupa. Described by Lane (1953). Thorax: Scutum, metathorax without spherical sensory pits. Respiratory organ (Fig. 101F): Broadly flattened, with spiracles along outer margin. Abdomen (Fig. 105A): Segments 3–7 somewhat expanded laterally. Paddle only moderately elongate; apex simple, without socketed spine.

Larva. Described by Lane (1953).

Egg. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella davisi is known from Honduras and Haiti, south to Ecuador, Trinidad and Tobago, French Guiana and Brazil (Fig. 128) at altitudes ranging from 0–637 m. Specimens have been collected through rearing, light traps and sweeping .

The allotype of C. nigra examined here was reared from a larva collected in a lagoon ( Lane 1939a) and all other reared material came from specimens collected from small to large ground pools in Honduras, Costa Rica and Brazil (Belem).

TAXONOMIC DISCUSSION: Males and females were associated through the shared presence of a common pigmentation pattern and were reared together from one site in Cahuita National Park in Costa Rica and another in Trinidad and Tobago. Adults were collected together with light traps in one location in Haiti, one location in Trinidad and Tobago and one in French Guiana. Both males and females of this species are quite variable in pigmentation (that of the katepisternum and anepimeron), relative flagellomere lengths and number of setae on the clypeus. Male varied significantly in the distribution of sensilla coeloconica on some of the flagellomeres. I strongly suspect the presence of two or more species in the samples at hand but more specimens are needed to sort these further.

Two females from 24 km SW Cayenne, Guyane, French Guiana, 5 m, 1–2-II-1965 ( USNM) were very similar to C. davisi but had the ventral portion of the katepisternum pale and a single sensilla coeloconica on each of flagellomeres 1 and 6–13. Of these two specimens, one had slender scales on the midfemur and the other only simple setae. They may represent peculiar variation or perhaps undescribed species .

One female from Sendero Bobocara, Hitoy Cerere Biological Reserve, Costa Rica, 300 m, 17-XI–17-XII- 1999 (INBC) keyed to this species but the midfemur was more stout and had a slightly darkened base and the sensilla coeloconica were distributed on flagellomeres 1–2, 9–13 with two sensilla coeloconica on flagellomeres 1–2, 10–13. It likely represent an undescribed species.

One male collected from 5 km SE Cayenne, Guyane, French Guiana on 2–3-II-1965 ( USNM) keyed to this species but may also represent an unnamed species and was excluded from the description here. It had two stouter setae arising just ventral to the dorsomedial setae (not present in C. davisi ) and the anterior dorsomedial seta was of nearly constant diameter for most of its length and tapered near its apex .

The application of the name C. davisi to this species is tentative. The syntype series was originally composed of at least one male and one female. A female was designated as the lectotype by O.H. Casal in Belkin et al. (1968) who reported on the details of the labeling and stated that it was housed in INMA. The specimen could not be found by Juan C. Mariluis currently at that museum (pers. comm.). There is no evidence that Lane saw the original specimens but he considered his C. nigra to be a synonym of C. davisi ( Lane 1951) and this decision is followed here. This conclusion can hopefully be tested if the lectotype of C. davisi is found in the future.

There is some confusion about the type material of C. nigra . Lane (1939a), in his description of this species recorded a male holotype, a female allotype and four male paratypes. The holotype was a specimen collected from Maracajú, Mata Grosso, Brazil and the allotype and paratypes were collected from São Paulo, São Paulo, Brazil. Belkin et al. (1971:29) reported the holotype male to be represented by a leg left on the pin and a genitalia (no. 204) on a slide together with those of a paratype (no. 877). I examined four specimens from the type series of C. nigra (one of these only a genitalia on a slide). A female was labeled as the allotype and the three males remaining as paratypes. One of the males, although labeled as a paratype, came from Maracajú and, because Lane (1939a) recorded only the holotype from this locality, it is likely the holotype of C. nigra . The genitalia had been mounted on a microscope slide and the remainder, originally on a pin, is now on a separate slide; both the pinned specimen and the slide were labeled with the number 877. I have added a holotype label to both slides to indicate this. The single male genitalia on a slide (No. 875, slide no. 204) had no associated pinned specimen, cannot be confidently identified and was not included in the description here; nor did it have a second genitalia on the slide as reported by Belkin et al. (1971). The remaining male paratype and allotype are both labeled from São Paulo (as described by Lane 1939a). The remaining two paratypes appear to be missing.

The holotype of C. nigrescens was originally on a pin but is now on a microscope slide. It was indistinguishable from that of C. nigra and therefore considered to be a synonym of C. davisi . The female paratype of C. nigrescens is here identified as C. truncata .

MATERIAL EXAMINED: Holotype, adult male on 2 microscope slides, labeled “ HOLOTYPE Corethrella nigra Lane, 1939 ", “ Paratype ”, “ Corethrella nigra Lane 38", “877", “Maracajú, Mato Grosso, Brasil ”, “Servico Febre Amarela, M.E.S., Bras.”, “RC Shannon Collection”, “Maio 1937”, “ Corethrella davisi Shannon and Del Ponte Det. A. Borkent ” and “ HOLOTYPE Corethrella nigra Lane, 1939 , Corethrella nigra Lane, 1939 , Paratype ♂ term. M. Grosso, Maracajú, Shannon, No. 877, Lamina 205, Divisao 4, Gavela 134, Universidade de S. Paulo, Instituto de Higiene Parasitologia”, “ Corethrella davisi Shannon and Del Ponte Det. A. Borkent ” ( DEFS). Allotype ♀ C. nigra , São Paulo, Brazil, VIII-1933 (date not on label, taken from Lane, 1939a) ( DEFS); 1 ♂ paratype C. nigra , São Paulo, Brazil, 1-IV-1937 ( DEFS); holotype, female adult on microscope slide, labeled “holotipo, Corethrella nigrescens , on horse etc. Magé, 18-3-40, Dr. Sha & Ottoni, S279 T2785, Corethrella davisi Shannon and Del Ponte Det. A. Borkent (DEFS) ; 1 ♀, Lancetilla, Tela, Atlantida, Honduras, 50 m, 9-II-1972 ( USNM); 1 ♀, Boca Tapada, San Carlos, Prov. Alajuela, Costa Rica, 50–100

m, 23-VI–23-VII-2004 ( INBC); 1♂, 1 ♀, Laguna Gandoca, Prov. Limón, Costa Rica, 0–50 m , 17–23-V-2004 ( INBC); 3 ♂, 1 ♀ and their pupal exuviae, 6 pupae, Cahuita National Park , Limón, Costa Rica , 25-V-2000 (1 ♂, CNCI, remainder to INBC); 1 ♀, 3 km E. Cahuita, Costa Rica , 29-X-1993 ( CNCI); 1 ♂, Outskirts of Finca Porvenir , Villavicencio, Meta, Colombia, 450 m , 19-VII-1971 ( USNM); 1 ♂, Outskirts of Finca La Corocora , Villavicencio, Meta, Colombia, 450 m , 17-VII-1971 ( USNM); 2 ♀, Coca, Napo River, Napo, Ecuador , V-1965 ( CNCI); 2 ♂, 5 km SE Cayenne , Guyane, French Guiana, 5 m , 31-I–1-II-1965 ( USNM); 1 ♂, 1 ♀, 5 km SE Cayenne , Guyane, French Guiana, 5 m , 2–3-II-1965 ( USNM); 4 ♀, 24 km SW Cayenne , Guyane, French Guiana, 5 m , 1–2-II-1965 ( USNM); 2 ♂, 1 ♀, near Port au Prince , Haiti ( USNM); 2 ♀, Nariva, “Bush Bush Forest “, Trinidad and Tobago, 1 m , 2–3-XI-1965 ( USNM); 1 ♂, 1 ♀, St. Andrew , “Turure Forest “, Eastern Main Rd. 26 milepost, 30 m , Trinidad and Tobago, 27-VIII-1966 ( USNM); 1 ♂, St George, “Agua Santa “, 30 m , Trinidad and Tobago, 29-VII-1965 ( USNM); 1 ♂, Rio Grande Forest , Trinidad and Tobago , 6–15-III-1963 ( USNM); 1 ♀, as for previous locality but 1-III-1963 ( USNM); 1 ♂, Borodini, Taubaté, São Paulo, Brazil , XII– 1948 ( USNM); 1 ♀, Bahia, Brazil, 1931 ( BMNH); 1 ♀, Reserva de Aura , IPEAN, Belem, Brazil, 1–10 m , 7- VIII-1969 ( USNM); 1 ♀, Macambo Forest , IPEAN, Belem, Brazil, 20 m , 12-VIII-1969, BRA 30 ( USNM); 1 ♀, Guana River Pump Stations, Instituto de Pesquisas e Experimentacao Agropecuarias do Norte, nr Belem, Para, Brazil, 30 m , 29–30-IX-1970 ( USNM) .

DERIVATION OF SPECIFIC EPITHET: The name davisi was named after one of the collectors of the type specimens.