Collections of the leaf beetle Henosepilachna elaterii Rossi, 1794 (Protozoa: Microspora) were carried out monthly from July 1988 to June 1991, from melon and cucumber plants in Senegal. Of the 1895 larvae and adults collected and examined, 1223 (64.53%) were infected with Nosema henosepilachnae Toguebaye and Marchand, 1984. The monthly infection prevalence ranged from 51.28% to 87.30%. These observations indicate that the infection due to N. henosepilachnae is prevalent in the natural populations of H. elaterii.
