Diurnal Emergence of Xyleborus ferrugineus (Coleoptera: Scolytidae) from Cacao Trunks in Ecuador and Costa Rica1

Abstract

Investigations of the factors controlling diurnal emergence of adults of Xyleborus ferrugineus (F.) from Theobroma cacao L. were conducted under field and laboratory conditions in Ecuador and Costa Rica. Beetle-infested sections of trunks were caged, kept under natural and controlled conditions of light and temperature, and counts of adults emerged made at defined intervals. Emergence in nature was primarily crepuscular. The peak of emergence was sometimes shifted or less sharply defined under artificial conditions but was always observed when either light or temperature was varied with the ambient conditions. Constant light and temperature completely disrupted synchronization of emergence.