Insects infesting sorghum (Sorghum bicolor L. Moench) panicles in northern Ghana. 1. Distribution, species composition, and damage potential

English

Surveys in the Upper East Region showed that sorghum panicles were attacked by an insect pest complex of which midge, mirid and pentatomid bugs and head caterpillars were most prominent. Midge was most important on late-planted sorghums while mirid bugs constituted the main pests of early sorghums. The mirid bug complex (Heteroptera: Miridae) was dominated by Eurystylus oldi (Poppius), but Creontiades pallidus (Rambur), Campylomma angustior (Poppius), Taylorilygus sp. and Megacoelum apicale (Reuter) also proliferated on most farms. Important predators associated with head bugs included earwigs, Forficula senegalensis Serville (Demaptera: Forficulidae) and assassin bugs, especially Cosmolestes pictus Klug (Heteroptera: Reduviidae). Yield loss estimates showed that controlling either head bugs or midge alone increased grain yields by 23-35 and 26-38 per cent, respectively, while controlling both pests increased yield by up to 63 per cent. Farmers recognized panicle feeders as pests on their crops, but usually did not think they caused economic damage; hence, farmers made no conscious efforts to control them. This is probably because most of them grow local guinense-type sorghums, which are known to be less susceptible to panicle pests compared to the improved caudatum types.

Tanzubil, P. B.; Alem, A.; Zakariah, M.