Meeting Abstract
P3.112 Sunday, Jan. 6 Growth, chemical and caloric composition of the fat body during metamorphic commitment in 5th instar Manduca sexta BUSTIILLO, SN*; HELM, BR; DAVIDOWITZ, G; University of Arizona, Tucson; University of Arizona, Tucson; University of Arizona, Tucson bhelm@email.arizona.edu
The onset of metamorphosis in insects occurs in close correlation with the attainment of a critical weight late in larval growth. At this size, time to metamorphosis becomes fixed irrespective of continued feeding and growth because the hormonal signaling that commits the larva to metamorphosis is irreversibly initiated. Larval resource acquisition and storage are an important component of successful metamorphosis and reproductive provisioning in the adult stage of life. This suggests that resource accumulation during the larval phase should be a critical factor in determining when, and at what size, commitment to metamorphosis occurs. Our study addresses the question, “What role does larval resource storage play in attainment of the critical weight?” We examine resource accumulation by quantifying the growth, chemical composition, and caloric content of the fat body in growth-phase 5th instar Manduca sexta larvae reared on five environmental treatments of diet quality and temperature. We summarize our findings within the context of attainment of the critical weight.
