Disersus Sharp, 1882

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

Disersus Sharp, 1882 Figs 1, 2, 9-22

Diagnosis.

This genus can be distinguished from all other genera of Larainae that occur in South America by the following combination of characters: its large size (5.6-10.1 mm), distinct pronotum, which lacks a transverse depression across the apical third (Fig. 21), and elytron lacking an accessory stria (Fig. 18).

Distribution.

Members of this genus occur in Central and South America, as far north as Costa Rica and as far south as Cuzco, Peru ( Spangler and Santiago-Fragoso 1987).

Habitat.

Disersus species can be found in fast-flowing streams and rivers, clinging to rocks and flying upstream in riffles and cascades. They rapidly enter and exit the water with great ease, carrying with them a silvery air bubble. They can be found in streams by looking for moving teardrop shaped air bubbles on the downstream sides of rocks with water cascading over them. Individuals of this genus are also commonly found at UV and mercury vapor lamps (pers. obs.).