Ecology of rice stem borers in Western Burkina Faso

Abstract

Stem boring insect pests are one of the most damaging groups to rice crop. This study aims at a better knowledge of these species in an integrated management perspective. The study was conducted on irrigated rice schemes in the Kou Valley and Karfiguéla during the 2019 wet season and the 2019-2020 dry season. The sampling technique consisted of weekly entomological assessments. Samplings were carried out from the tillering stage to rice maturation through mowing, trap surveying, sampling and dissection of rice tillers and other host plants showing symptoms of 'dead hearts' or 'white heads'. Results showed that Chilo species were more abundant in the Kou Valley (86,25%) while Maliarpha separatella (24,67%) and Sesamia calamistis (3,25%) were more abundant in Karfiguéla. A positive and significant correlation was found between Maliarpha separatella’s populations and relative humidity. The same type of correlation was found between the populations of Chilo species and rainfall. Thirty-six species of natural enemies associated with stem borers were identified. These results can serve as a starting point for further research to develop an integrated management method for rice stem borers in western Burkina Faso.