The natural diet of the Notonectidae: field trials using electrophoresis

Abstract

ABSTRACT. Field trials were conducted on populations of two sympatic species of the waterbug Notonecta (Hemiptera: Heteroptera), to examine their natural diet using the electrophoretic method of gut contents analysis. Fingerprint esterase bands were identified from thirty‐three potential aquatic prey types; gut contents of different instars of both species of Notonecta from the field were analysed. The level of prey identification possible ranged from 73% in fifth instar N.glauca L. to 100% in third instar N.viridis Delcourt. Type A errors, where no prey remains were detected from a full gut, were found in only 3% of the specimens analysed. Data on gut states, the number of prey types per gut and details of aquatic prey found in the diet of different instars of field‐collected Notonecta are presented. These results are compared with previous data on notonectid diets, and the relative merits of different methods of diet analysis are discussed.