DIURNAL ACTIVITY, TEMPERATURE RESPONSES AND ENDOTHERMY IN 3 SOUTH-AMERICAN CICADAS (HOMOPTERA, CICADIDAE, DORISIANA-BONAERENSIS, QUESADA-GIGAS AND FIDICINA-MANNIFERA)

1. Measurements of body temperature (T-b) in the field demonstrated th at endothermic cicadas regulate T-b by behavioral mechanisms as well a s by endogenous heat production. 2. The T-b of endothermically active cicadas without access to exogenous heat is approximately the same as the T-b of basking cicadas. 3. Dorisiana bonaerensis (Berg) and Quesad a gigas (Olivier) raise T-b in the field with the heat produced in Eig ht. 4. The thermal responses of a particular species are related to it s activity patterns and habitat. 5. Endothermy in cicadas may serve to uncouple reproductive behavior from environmental constraints; to cir cumvent possible thermoregulatory problems; to permit the utilization of habitats unavailable to strictly ectothermic cicadas; to reduce pre dation; and to optimize broadcast coverage and sound transmission.