A headcage technique to screen sorghum for resistance to mirid head bug, Eurystylus immaculatus Odh. in West Africa

A headcage technique to screen for resistance to sorghum head bug, Eurystylus immaculatus Odh.(Hemiptera:Miridae) was standardized for use in West Africa. Panicles infested at the half-anthesis to complete-anthesis stage had greater population build-up and suffered maximum grain damage, loss in grain mass, grain hardness and seed germination. Panicles with higher grain damage also showed greater severity of grain mould incidence. Maximum population build-up and grain damage were recorded in panicles infested with 20 pairs of adults. Panicles infested with 30-40 pairs of bugs generally showed a decrease in population build-up, possibly because of crowding. Head bug numbers decreased with a decrease in panicle size, while the extent of grain damage increase