Changes in the respiratory metabolism of Rhodnius prolixus as induced by temperature

Abstract

Moulting is delayed by exposing Rhodnius larvae to sub-lethal high temperature either before or after feeding. During exposure of fed larvae, the respiratory rate continues to decrease until it reaches very low levels. If the insects are transferred to normal temperature, the rate temporarily decreases and then increases towards the time of ecdysis. In the unfed larvae, however, the level of oxygen consumption remains steady. When fed larvae are kept at high temperatures after the critical period for moulting, the oxygen consumption decreases and then remains at a relatively high level until the insects ecdyse. In insects where moulting is delayed, either by heat treatment before or after feeding, or by anus-blockage, or by starvation, the metabolic rate is lower than that of normal insects. The effects of temperature on the metabolic activity are discussed and are correlated with the induced arrest or delay of moulting.