Day-to-day change in relative humidity and the activity of Culex nigripalpus (Diptera: Culicidae).

Abstract

A variate-difference method of analysis was used to study bait- and suction-trap collections of the mosquitoes Culex nigripalpus Theobald and Aedes tacniorhynchus (Wiedemann). Day-to-day differences (first differences) in successive catches of C. nigripalpus (but not of A. tacniorhynchus ) were correlated significantly with day-to-day differences (first differences) in the relative humidity 1 hour after sunset. In spite of a demonstrated relationship of rainfall to the level of relative humidity 1 hour after sunset, the relationship of change in C. nigripalpus to change in relative humidity existed also on days without rain. Day-to-day differences in trap collections are discussed as a measure of population activity.