Insect pests of dried cassava ('kokonte') in Ashanti and Brong Ahafo Regions of Ghana.

Abstract

Insects are among the most important agents of postharvest losses of dried stored produce including cassava. In a study to identify the most important insects and assess the damage, dried cassava samples from marketing centers in 8 districts each in Ashanti (Mampong, Nkawie, Konongo, Tepa, Nkenkasu, Kumasi, Ejura and Bekwai), and Brong Ahafo (Berekum, Dormaa Ahenkro, Techiman, Sene, Acherensua, Sunyani, Kintampo and Bechem) were incubated in the laboratory. For each sample, a questionnaire was administered to collect information on the cassava varieties processed, method of preparation, drying and storage. Ninety-nine percent of ‘kokonte' samples collected from the Brong Ahafo region were sun dried compared with 59% from Ashanti. Samples from Ashanti had been predominantly stored in open baskets (46%) while in the Brong Ahafo the principal method had been in empty fertilizer sacks (42%). Much of the kokonte ready for the market in both regions were stored for a maximum period of one week. The red skin variety of cassava is preferred to the white skin accounting for 67% and 85% of kokonte from Ashanti and Brong Ahafo, respectively. Eleven insect species, all beetles from six families were identified from the two regions. The coffee bean weevil, Araecerus fasciculatus (Degeer) (Coleoptera: Bostrichidae), was the most predominant species. Other important species were Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae), Cryptolestes sp. (Coleoptera: Cucujidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Dinoderus minutus (Fabricius) and Cathartus quadricollis Guerin (Coleoptera: Silvanidae). They were important because of their numbers and the potential to cause damage. Of significance was the occurrence in small numbers in both regions of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), in samples. The potential of this insect to cause damage and implications for post harvest storage of dried produce are discussed. Journal of the Ghana Science Association Vol. 9 (2) 2007: pp. 9-17