Circadian Emergence Rhythm of a Tropical Scolytid, Xyleborus ferrugineus12

Abstract

A diurnal rhythm of Xyleborus ferrugineus (F.) adult emergence from trunk sections of the host tree, Theobroma cacao L., was studied under controlled conditions of light and temperature to determine the type of periodism involved and the controlling factors. An endogenous circadian rhythm with a 22.5-hour free-running period was observed in constant darkness at 24.5°C. A periodicity fade-out progressed to complete asynchronization after 9 days in constant darkness. Phase shifting and synchronization were strongly influenced by both light and temperature.