Potential Threat of Bruchids on Soybean Production in Sub-Saharan Africa

Soybean production in sub-Saharan Africa (SSA) has been increasing in recent years in part due to the efforts of several national and international research agencies, including the Soybean Innovation Laboratory (SIL). SIL’s mission to increase utilization and production of soybean in SSA has led to several facets of research including cultivar development to increase yield through the Pan-African Soybean Variety Trials (PATs). Several abiotic and biotic stresses can decrease yield, including pathogens and pests that attack seed. While evaluating seed lots from 32 PAT locations, we identified bruchids and/or bruchid-damaged seed in nine locations in four countries (Cameroon, Malawi, Mozambique, and Rwanda). The most severe damage and infestation was recorded in Bwanje, Malawi, with 28 of the 40 seed lots infested. Seed damage ranged from 0.6 to 100% among the 28 infested seed lots. Adult bruchids discovered at the Bwanje location were identified as Callosobruchus chinensis, or the Chinese bruchid. No adults were found in other locations. Bruchids are a destructive storage pest of legumes, and monitoring the different species attacking soybean will help researchers and producers understand the potential threat of bruchids to soybean production in SSA as well as help implement the best management practices.