A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species Author Maier, Crystal A. text ZooKeys 2013 329 33 91 http://dx.doi.org/10.3897/zookeys.329.4961 journal article http://dx.doi.org/10.3897/zookeys.329.4961 1313-2970-329-33 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.). Figures 1-4. 1 Map of Venezuela, showing collection localities for Disersus inca (Triangle), Disersus chibcha (Circle), and Potamophilops bostrychophallus (Square) 2 Disersus dasycolus (White Circle), Hypsilara royi (White Triangle), Roraima carinata (White Square), Hypsilara breweri (Black square), Hypsilara sp. (Black Circle) 3 Hexanchorus dentitibialis (Circle), Phanoceroides sp. 1 (Triangle), Hexanchorus homaeotarsoides (Square) 4 Hexanchorus falconensis (White Square), Hexanchorus mcdiarmidi (White Circle), Hexanchorus flintorum (Black Circle), Hexanchorus inflatus (White Triangle). Figures 5-8. 5 Map of Venezuela, showing collection localities for Pharceonus volcanus (White Triangle), Pharceonus grandis (White Circle), Neblinagena prima (White Square), and Neblinagena doylei (Black Circle) 6 Phanocerus clavicornis (Black Circle) 7 Phanocerus congener (White Circle) 8 Phanocerus rufus (Black Circle), Pharceonus ariasi (Black Square). Figures 9-12. Disersus chibcha : 9 Dorsal habitus 10 Ventral habitus 11 Lateral habitus 12 Metatibia, male. Figures 13-17. Disersus dasycolus : 13 Dorsal habitus 14 Ventral habitus 15 Lateral habitus 16 Metatibia, male 17 Protibia, male. Figures 18-22. Disersus inca : 18 Dorsal habitus 19 Ventral habitus 20 Lateral habitus 21 Pronotum, dorsal view 22 Metatibia, male.