Activity of catalase in overwintering females of mosquitoes Culex pipiens, Culex torrentium, and Anopheles maculipennis s.l. (Diptera: Culicidae)

Abstract

Catalase, an antioxidant enzyme, is present in tissues of most organisms. In mosquitoes, such as Culex pipiens L., catalase maintains prolonged lifespan and fertility of hibernating females. The sibling species for Cx. pipiens, Cx. torrentium Martini, is more abundant and even prevalent over Cx. pipiens in regions with short growing season and cool climate. Females of Cx. torrentium are difficult to discriminate from Cx. pipiens by morphological traits and can be identified probabilistically using r(2+3)/r3 wing vein index. The present study shows that in Cx. pipiens/torrentium, there is a significant positive correlation between r(2+3)/r3 wing vein index and catalase activity (rho=0.606, p=0.0027), indicating that enzyme activity in Cx. torrentium, in general, higher than in its sibling species, Cx. pipiens. When overwintering females of Cx. pipiens and Anopheles maculipennis s.l. were compared, definitely higher catalase activity in A. maculipennis s.l. was found, and this is in good agreement with the observations that A. maculipennis s.l. females choose cooler hibernacula. Higher catalase activity in overwintering females of Cx. torrentium and A. maculipennis s.l. (in comparison with that of Cx. pipiens) may be considered a better adaptation of Cx. torrentium and A. maculipennis s.l. for stressful conditions during overwintering.