Corethrella (Corethrella) pallida Lane, 1942

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 79-81

Corethrella (Corethrella) pallida Lane

Corethrella (Lutzomiops) pallida Lane 1942:129 . Type locality: Porto Bello, [Colon], Panama (given by Lane 1953:98). Holotype ♂ (USNM).

Lutzomiops pallida: Lane 1953:98 .

DIAGNOSIS: Male adult: nearly the only extant species of Corethrella in the New World (not distinguishable from some C. blanda ) with a nearly completely plain wing (with slight non-discrete pigmentation at midlength) (Fig. 62D), wing length of males = 1.21–1.60 mm, palpus entirely dark brown (as in Fig. 8A), scutum light brown and somewhat variably pigmented (but not with lateral vitta dark brown), katepisternum with dorsal margin pale and remainder either completely pigmented or somewhat mottled, halter as dark as scutellum (as in Fig. 43C), midfemur with darker pigmentation at its base and hind tibia with at most slightly darker pigmentation at very base (as in Fig. 43C). Female adult: only extant species of Corethrella in the New World with flagellomeres 1–3 short ( Fig. 27F), a nearly completely plain wing (with slight non-discrete pigmentation at midlength) (Fig. 67N) and the hind tibia with at most slightly darker pigmentation at very base ( Fig. 43C).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 8A). 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. 20G, 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. 43C): Light brown, with scutum somewhat mottled, katepisternum with dorsal portion pale with remainder uniformly light brown to mottled, 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. Ventral portion of posterior anepisternum triangular, uniformly brown, with anterodorsal margin thick. Wing (Fig. 62D): Apex of R 2 slightly basal to apex of M 1. Mostly plain, with very light poorly defined midlength band, anterior margin of wing uniformly pigmented; veins (other than costa and wing margin) with well-developed scales. Halter as dark as scutellum. Legs (as in Fig. 43C): Light brown, with base of midfemur, in some the apex of the midfemur, in some very base of hind tibia more darkly pigmented; fore-, hind tibia with patch of dark scales. Femora, tibiae and at least some tarsomeres with broad 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 of intermediate thickness. Abdomen (Fig. 77E): Uniformly light brown. Genitalia (Fig. 87B): Gonocoxite uniformly pale or very light brown, somewhat strongly tapering; anteromedial area with distinctively elongate spicules; with well-defined dorsal row of setae, with basal setae stouter than other scattered setae on gonocoxite, with 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, anterior seta more or less of even thickness for most of length, tapering near apex, posterior seta tapering from base anterior seta more stout, bases joined by sclerotized plate. Gonostylus (in retracted position) straight, basal 0.6 thick, narrowed beyond to rounded apex; one elongate, thick subbasal seta, situated posteroventrally; apical seta slender, elongate, simple. Aedeagus somewhat squat, 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). Antennal flagellomeres as in Fig. 27F, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 17W) squarish. Mandible with small, pointed teeth. Palpus as in Fig. 33Y. Wing (Fig. 67N). 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 light brown.

Pupa. Mostly undescribed. Thorax: Scutum, metathorax without spherical sensory pits. Respiratory organ (Fig. 101D): Broadly flattened, with spiracles along outer margin. Abdomen ( Fig. 10D): Segments 3– 7 strongly expanded laterally. Paddle only moderately elongate; apex simple, without socketed spine.

Larva. Undescribed.

Egg. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella pallida is known from Costa Rica, Panama, Colombia and Venezuela (Fig. 132) at altitudes ranging from 50–2270 m. The altitudinal range of this species is striking and is greater than nearly all other species of Corethrella .

Nearly all the specimens examined were reared from larvae or pupae collected from epiphytic bromeliads. One specimen was reared from a treehole and one female was collected with a Malaise trap. The holotype was stated to have been reared from a larva collected in the bromeliad Tillandsia ( Lane 1942, 1953).

TAXONOMIC DISCUSSION: Males and females were associated through the shared presence of a common pigmentation pattern and were reared from the same bromeliads at two locations in Costa Rica and one in Venezuela. However, there is some uncertainty regarding the name of this species because males cannot be distinguished from many C. blanda and this is especially so because the holotypes of both C. pallida and C. blanda are male. The male holotype of C. pallida was reared from a bromeliad in Panama and I used this biological information to identify those reared from bromeliads in Costa Rica as C. pallida . I examined male and female pupal exuviae of these reared Costa Rican C. pallida and they appeared indistinguishable to me; I therefore considered all these reared males to be conspecific with the females and to be C. pallida . The male holotype of C. blanda is lost but examination of female paratypes, reared from a ground pool with the male holotype, confirmed the identification of C. blanda (because females can be identified with certainty). Corethrella blanda were either not reared or were reared from ground pools (included the type series). It remains possible that the pupa of C. blanda (not examined here) is similar to that of C. pallida and therefore that some of the males of C. pallida identified here are actually those of C. blanda (and vice versa).

The male holotype of C. pallida was in moderately good condition but was somewhat distorted. This is almost certainly due to the specimen being teneral, as evidenced by bent plumose setae on the antennae and bent leg segments. The genitalia was broken into pieces but critical features were yet visible. The holotype was originally on a pin but was placed on a microscope slide. The holotype had no locality label but Lane (1953:98) reported the type locality as Porto Bello , Panama .

The females from Pejibaye and Finca La Selva, Costa Rica had relatively longer flagellomeres 2 and 3 and may represent a distinct species. I was unable to distinguish the associated males from those of other C. pallida , which may not be significant considering not all male C. pallida and C. blanda can be distinguished from one another.

A male and female from Hitoy Cerere Biological Reserve keyed to C. pallida but were distinctly darker, somewhat larger and the legs appeared more slender than C. pallida . In addition, the female had significantly longer flagellomeres 4–9. They likely represents another unnamed species but the specimens were rather rubbed (including the wing scales) and parts of the legs were missing and therefore is not further described. The female was collected on Sendero Espavel, 560 m, 14–25-III-2003, with a yellow pan trap and the male with a malaise trap at 200–300 m on 17-XI-1999. Both specimens are housed in the INBC.

A male from Sector Mata-Mata , PNN Amacayacu, Amazonas, Colombia, 150 m, 11–24-IV-2000 ( CNCI) was similar to males of C. pallida but had an apically narrower and more thickened aedeagus. It may represent an undescribed species .

MATERIAL EXAMINED: Holotype, male adult on microscope slide, labeled " Corethrella pallida Lane, 1941 , holotipo, Tillandsia , 497" ( USNM). 1 ♂ with larval and pupal exuviae, 2 ♀, each with larval and pupal exuviae, Tayutic, Barbilla National Park, Turrialba , Cartago, Costa Rica, 1600 m, 19-V-2001 ( INBC); 1 ♀, with pupal exuviae, as previous locality but 16-IV-2002 ( CNCI); 1 ♂, 10 km S Guapiles, Limón, Costa Rica, 600 m, 11-IX-1965 ( USNM); 3 ♂, 1 ♀, Finca La Selva , Puerto Viejo, Heredia, Costa Rica, 100 m, 6-VIII-1971 ( USNM); 2 ♀, as for previous locality but 27-VIII-1971 ( USNM); 1 ♀, as for previous locality but 28-VIII- 1971 ( USNM); 1 ♀ with pupal exuviae, Potrero Grande, Buenos Aires, Puntarenas, Costa Rica, 2270, 2-VIII- 2000 ( INBC); 1 ♀ with larval and pupal exuviae, Tapantí National Park , Cartago, Costa Rica, 1300 m, 12-II- 2000 ( INBC); 2 ♀ each with larval and pupal exuviae, Sendero Heliconias, Fortuna, San Carlos, Alajuela, Costa Rica, 520 m, 20-XI-2002 ( INBC, CNCI); 1 ♀, Est. Quebrada González, Braulio Carrillo National Park , Pocoi, Limón, Costa Rica, 400–500 m, 21-VIII-2002 ( INBC); 3 ♀, 2 with larval and pupal exuviae, 1 with pupal exuviae, 1.3 Km E. de la Estación Barbilla, Peralta, Turrialba, P.N. Barbilla, Cartago, Costa Rica, 500 m, 23-V-2001 (1 ♀ with larval and pupal exuviae, CNCI; remainder to INBC); 1 ♂ with larval and pupal exuviae, Santa Elena, Reserva Biológica Monteverde, Centro Científico Tropical, Refugio El Alemán, Puntarenas, Costa Rica, 960m, 1-II- 2003 ( INBC); 1 ♀, Est. Sierpe, P.N. Tortuguero, Costa Rica, 50–100 m, 14–21- VIII-2004 ( INBC); 1 ♂, pupal exuviae, 1 ♀, larval and pupal exuviae, Sendero Mirador Las Cataratas, 4.2 Km S. de la Iglesia de Pejibaye , Refugio de Vida Silvestre La Marta , Pejibaye, Jiménez, Costa Rica, 960m, 3-VIII- 2004 ( INBC); 1 ♀, Leticia, Buenaventura, Valle, Colombia, 80 m, 9-VI-1966 ( USNM); 1 ♂, 1 ♀, Trail NE of Rancho Grande , Maracay , Aragua, Venezuela, 1100 m, 5-VII-1969 ( USNM).

DERIVATION OF SPECIFIC EPITHET: The name pallida probably refers to the pale wings of this species.