VATNICK, I; MADIGOSKY, SR; CARANCI, A*; OJO, B; MORGAN, R; Widener University; Widener University; Widener University; Widener University; Cincinnati Zoo & Botanical Garden: Body mass and metabolic rate changes of Hercules beetles, (Dynastes hercules ) during ontogenesis

Little information is available concerning changes in growth and metabolic rate that occur in the various developmental stages during insect life-cycles, including the subject organism, Dynastes Hercules. We documented the changes in body mass and weight specific metabolic rate in Dynastes Hercules at three distinct developmental stages: third instar larvae, pupae, and adults. The overall mass of larvae was reduced by 68% after pupating, and another marked decrease occurred when pupae transformed to adults. On average, the mass of third instar larvae, pupae and adults was 67g, 41g and 21g, respectively. Metabolic rate declined with advancing life stage. Larval oxygen consumption was 0.28 + 0.017 ml/g/h, more than double that of pupae (0.12 + 0.02 ml/g/h) and over four times the oxygen consumption rate of adults (0.052 + 0.005 ml/g/h). We also tested the effect of temperature on the metabolic rate of larva. Weight specific metabolic rate increased between 20 C and 30 C with a Q10 of 1.98 a value typical for ectotherms.