Assessment on Distribution, Biology and Management of Maize Stem Borer (Busseola fusca Fuller) in Ethiopia

Abstract

Cereal crops (maize, sorghum, millet, rice) are extremely important crops grown in Africa for human intake. Of the various insect pests attacking cereal crops in Africa, lepidopteran stem borers are by far the most injurious. A parasitoid, Cotesia flavipes, was introduced from Pakistan for biological control of C. partellus and caused a 32–55% decrease in stem borer densities. Stem borers, encompassing the larvae of a group of lepidopterous insects, and parasitic witch weeds, particularly Striga hermonthica and S asiatica, cause major yield losses in subsistence cereal production throughout the country, Ethiopia. Studies are described that have led to the development of a ‘push-pull’ strategy for minimising stem borer damage to maize and sorghum. This involved the selection of plant species that could be employed as trap crops to attract colonisation away from the cereal plants, or as intercrops to repel the pests. The two most successful trap crop plants were Napier grass, Pennisetum purpureum, and Sudan grass, Sorghum sudanensis. In terms of stem borer control, the plant chemistry responsible involves release of attractant semiochemicals from the trap plants and repellent semiochemicals from the intercrops. With M minutiflora, parasitism of stem borers was also increased by certain chemicals repellent to ovipositing adults. This review provides information on B. fusca for the production of maize and sorghum in Ethiopia, with emphasis on their distribution, pest status and yield losses, diapause, natural enemies, cultural control, host plant resistance, and biological control. Special attention is given to Busseola fusca the most important pests of maize and grain sorghum.

Keywords: Botanical: push-pull stem borers; trap crop; intercrop; rotation: semiochemical