THERMAL STRESS AND ANOMALOUS DEVELOPMENT OF MOSQUITOES (DIPTERA: CULICIDAE): IV. AEDES COMMUNIS

Abstract

When thermal pressures within the range of 19–24 °C are applied to developing larvae of Aedes communis, male traits are progressively suppressed and even eliminated in adults of the masculine genotype. Coincidentally female traits develop both internally and externally in these individuals and the degree of femininity is proportional to the temperature used. The sexual traits of individuals of the feminine genotype are unaffected by thermal pressures. This paper deals with the effects of thermal stresses on Aedes communis from Michigan in the United States and from Manitoba, Canada. Descriptions and delineations of the imaginal dimorphic organs of the masculine phenotype, functional female phenotype, and thermally induced female phenotype are included herein. Two different thermally responsive strains of this species exist in Manitoba while only one strain exists in Michigan. One strain may be separated from the other in a mixed population by the application of a closely controlled rearing temperature. The origin of some of the dimorphic structures in the sexes has been clarified here.