Meeting Abstract

P2.162  Thursday, Jan. 5  The effects of juvenile hormone modulation on development and stress-related behavior in Madagascar hissing cockroaches (Gromphadorhina portentosa). LEXA, C.M.*; DAVIS, J.E.; Radford University; Radford University

Growth, maturation, and stress are systems with close physiological relations. When conditions are stressful due to a lack of resources or extreme environmental conditions, energy is directed away from systems that are not essential for survival, such as reproduction. This martialing of resources for immediate survival at the cost of immediate reproduction may increase long-term reproductive output. In insects, the activities of these systems are partially regulated by juvenile hormone (JH); high levels of JH generally prevent a nymph from maturing into an adult state, while a reduction in juvenile hormone can induce reproductive development. We predicted that chronic stress, or chronically increased JH would lead to an overall delay in reproductive maturity, increased body size, and an increase in anxiety-related behaviors. In subjects with chronically decreased JH would exhibit inverse responses. To observe the effects of chronic low and chronic high JH levels we reared three different groups of Madagascar hissing cockroach nymphs for 9 months under exposure to one of three hormonal conditions; one group received an agonist to JH(methoprene), another group was given a JH antagonist (allostatin IV), and a control group received no manipulation. Growth, mortality, and fecundity of each group were monitored throughout the study. To test how JH levels affect stress related behaviors, three behavioral tests were performed; a photosensitivity test, an exploration test, and a food deprivation test. Here we present findings demonstrating the effects of JH modulation on both physiological and behavioral profiles.