Seasonal effects on cuticular permeability and epicuticular lipid composition inCentruroides sculpturatus ewing 1928 (Scorpiones: Buthidae)

Summary Third larval instar hemolymph of the fruitflyDrosophila hydei did not metabolize juvenile hormone (JH) at all developmental stages. In contrast, prepupal and pupal body fluid showed JH-esterase activity with a maximum at 4 h after puparium formation. In body wall and fat body of all developmental stages investigated, JH-metabolic activity was found. In both tissues JH catabolism was most active in the 120,000g supernatant and pellet. The 800g and 15,000g pellet showed a lower activity. In all subcellular fractions the JH-acid was identified as the predominant metabolite. There is evidence that JH-specific esterases are responsible for ester cleavage in the 120,000g supernatant. During mid and late third larval instar development in both body wall and fat body JH-esterase activity remains relatively constant.