SEASONAL DEVELOPMENT OF TREE-HOLE MOSQUITOES (DIPTERA: CULICIDAE) AND CHAOBORIDS IN RELATION TO WEATHER AND PREDATION1

Abstract. Four species of tree-hole mosquitoes (Diptera: Cu-licidae)and 1 species ofChaoboridae in temperate north Florida commence their vernal development as embryos or larvae. Ex-cept for Toxorhynchites rutilus, all species overwinter in various prepupal stages. Overwintering populations of Orthopodomyia signifera, Aedes triseriatus, and Anopheles barberi are sparser and younger in the presence of Tx. rutilus than in its absence. Vernal pupation occurs first among Tx. rutilus, followed by Or. signi-fera—Ae. triseriatus—An. barberi, and then the chaoborid Coreth-rella appendiculata. Toxorhynchites rutilus, Ae. triseriatus, and An. barberi all pupate over a brief period, while C. appendiculata and Or. signifera pupate over a period of several weeks. The over-wintering stages and the timing and variability of vernal de-velopment are interpreted as adaptations to seasonal harshness and to varying degrees of predation. The pattern of seasonal development is reviewed in the context of vector control. Seasonal development in arthropods is generally considered with respect to its physiological mech-anisms and environmental controls and in relation to variable seasonal harshness (Andrewartha 1952