A Comparative Study of Catalase Activity in Culiseta annulata (Schrank) and Culex pipiens L. (Diptera, Culicidae)

Abstract

Catalase is an antioxidant enzyme, which is important for lifespan extension and stress resistance during diapause in overwintering mosquitoes. Based on the preliminary observations on abundancies of Culiseta annulata (Schrank) and species of the genus Culex, overwintering in the Sablino Caves (Northwestern Russia), it was hypothesized that catalase activity in hibernating females might vary between species. When the individuals of Cs. annulata and Culex spp. on cave walls were counted during overwintering and their numbers were compared, a similar decrease in their numbers was found, but when catalase activity was analyzed, a significant difference between Cs. annulata and Cx. pipiens pipiens L. was revealed, with higher activity in Cs. annulata. Higher catalase activity in Cs. annulata, as compared with that in Cx. p. pipiens, was also revealed in males collected in fall, which indicates the true interspecific differences (not linked with blood consumption) and suggests a better resistance of Cs. annulata to low temperatures. The results also suggest that catalase activity may be a tool for chemotaxonomy of mosquitoes.