Disersus chibcha Spangler & Santiago-Fragoso, 1987

Maier, Crystal A., 2013, A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species, ZooKeys 329, pp. 33-91 : 35-37

Disersus chibcha Spangler & Santiago-Fragoso, 1987 Figs 1, 9, 10, 11, 12

For complete description and genitalia illustrations see Spangler and Santiago-Fragoso 1987.

Material examined.

COLOMBIA: Valle del Cauca: "COLOMBIA: Dept Valle; 4km W. Cisneros; 28-II-69; R.E. Woodruff; Blacklight trap" (2 paratypes USNM). VENEZUELA: Mérida State: "VENEZUELA: Mérida State; 8°44.114'N, 71°26.898'W, 873m; ca. 2 km S La Azulita; Cascada la Palmita; 21.vii.2009; leg. Shepard; VZ09-0721-01Z" (1 specimen SEMC). "Venezuela Mérida; Dtto. Justo Briceño; Cañada de San Jose; 14/15-VII-1990" "Colector:; J. Camacho" (1 specimen MALUZ). Táchira State: "Rio Frio; Venezuela, Tachi-; ra [ Táchira State]. 600m.; 2 –10-IX-1981” "F. Fernandez. Y; J. Clavijo; A. Chacon" (5 specimens MIZA). "Rio Frio; Venezuela, Tachi-; ra [ Táchira State]. 600m.; 20 –24-IV-1982” "Expedicion; Zoologia; Agricola" (2 specimens MIZA). "Venezuela: Táchira; Quebrada La Uraca San; Felix 300m 17-22-vi-1998; J. DeMarmels y A. Chacon" (1 specimen MIZA). "Venezuela: Táchira; Quebrada La Uraca San; Felix 300m 7-16-v-2002; J. DeMarmels y A. Chacon" (2 specimens MIZA). "Venez. Táchira; Sn. Felix Rio Uraca; 350m; 12 –19-iv-1996” "J. DeMarmels, A.; Chacon" (2 specimens MIZA). "Venezuela Táchira; La Blanca cr. Colon; La Fria 1000 m; 14-21-iv-1998; Cols. J. DeMarmels; A. Chacon" (1 specimen MIZA). Trujillo State: "Venezuela Trujillo; Mcpio. Escuque; El Prado. Rio Buena Vista; 05-IV-1992" "J. Camacho; O. Lisano; Colectores" (2 specimens MALUZ).

Diagnosis.

This species of Disersus can be distinguished from its congeners by the combination of an almost entirely bare metatibia (Fig. 12); blackish-brown femora; and indistictly produced elytral apices (Fig. 9), as well as its large size (~8.5 mm) (see Spangler and Santiago-Fragoso 1987).

Intraspecific variation.

This species varies slightly in size and coloration, from dark brown to nearly black. Additionally, the last abdominal ventrite of the male is notched, while the last abdominal ventrite of the female is slightly sinuate, and the elytral apices of the female are more acute than those of the male (see Spangler and Santiago-Fragoso 1987).

Habitat and distribution.

Previously, Disersus chibcha was known only from a blacklight trap at Valle del Cauca, Colombia ( Spangler and Santiago-Fragoso 1987). Subsequent collections of this species, given here, were from high gradient, medium-sized streams and waterfalls throughout the Mérida Andes in Venezuela (Fig. 1).

Associated species.

No other laraine species were collected with Disersus chibcha .