The effect of diflubenzuron (Dimilin® 25 WP) on some non-target aquatic insect and crustacean species

The study is aimed at evaluating, under laboratory conditions, the side effects of a commercial formulation of diflubenzuron (Dimilin® 25 WP), which is an insecticide considered a chitin synthesis inhibitor, on some non-targeted aquatic species. The effect of two lethal doses of Dimilin LC10 (3.9 ng/L) and LC50 (16 ng/L) previously determined on fourth instar larvae of Culex pipiens L. 1758 were tested on some non-target aquatic species, abundant in the Lake of Birds (Northeast Algeria), a site classified under Ramsar Convention. The tested species belonged to two classes of invertebrates (Insects and Crustaceans). The insects included four species of Heteroptera: Corixa punctata Illiger, 1807, Notonecta glauca Latreille, 1802, Anisops sardea Latreille, 1802 and Plea minutissima Leach, 1817, and one species of Coleoptera Berosus signaticollis Charpentier,1825. For benthic crustaceans Daphnia magna Straus, 1820 (Cladocera) was retained. The results showed significant mortality recorded in C. punctata and medium mortality for B. signaticollis, A. sardea, N. glauca, P. minutissima and D. magna. Three-way ANOVA indicated highly significant effects of species, dose, and time. According to the sensitivity to Dimilin, the pairwise comparison of Tukey's test indicates that the most sensitive species was C. punctata followed by B. signaticollis and the least sensitive was N. glauca, followed by D. magna; then A. sardea and finally P. minutissima.