Aspects of the biology of Ephestia cautella and Tribolium castaneum on fermented stored cocoa beans

Abstract

 Ephestia cautella (Walker) (Lepidotera: Pyralidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) are pests associated with dried fermented stored cocoa beans that cause extensive damage. The biology of these pests on cocoa beans in Ghana has not been well documented, especially on T. castaneum. Due to climate changes and improved/hybrid seedlings being released to farmers, it has become necessary to re-evaluate the biology and damage of these pests on fermented stored cocoa beans. The experiments were conducted in the Insectary laboratory of the Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Paired 0-1 day old E. cautella adults were placed in Petri dishes and covered with Kilner jars. The eggs laid daily by each female were carefully transferred onto 15 g cocoa beans in Petri dishes. The egg incubation period was four days, 31 days larval period and the pupal period of seven days. Unmated adult males lived for 12.1 days and females 7.9; mated males lived for 10.9 days and females 5.5. Paired T. castaneum were introduced on 2.0 g broken cocoa beans in Petri dishes. The average incubation period was nine days, 40 days larval period, and pupal period of five days.