INFLUENCE OF SOIL PHYSICAL FACTORS ON SURVIVAL AND DEVELOPMENT OF THE LARVAE AND PUPAE OF THE BEAN LEAF BEETLE, CEROTOMA TRIFURCATA (COLEOPTERA: CHRYSOMELIDAE)

Abstract

AbstractEffects of soil moisture, texture, and temperature on larval and pupal survival and development of the bean leaf beetle, Cerotoma trifurcata (Forster), were investigated in laboratory and greenhouse studies. In both cases, mortality rates were highest during the first instar, decreased during subsequent larval instars, then increased during the pupal stage. Under constant laboratory conditions, survival and adult weights were highest in wet and organic soils and lowest in dry and loamy sand soils. In wet and organic soils, developmental time was shorter than in other soils.Although survival/plant in the greenhouse was greatest in sandy clay loam, survival/nodule was greatest in organic soil.These studies, together with oviposition preference, egg survival, and larval movement experiments agree with field observations and provide some explanations for observed patterns of local and regional abundance of the bean leaf beetle in North Carolina.