The stem borers, Chilo partellus (Lepidoptera: Crambidae) and Busseola fusca (Lepidoptera: Noctuidae) cause extensive damage to maize in Africa with yield losses ranging from 20 to 80%. A cost effective habitat management for stem borers was developed for resource poor farmers in Kenya and is now being adapted in South Africa. This “stimulo-deterrent diversionary strategy” or a “push-pull” system involves the use of intercropping and trap cropping strategies. Two species of grasses, fodder sorghum (Sorghum bicolor x S. halepense) and Napier grass (Pennisetum purpureum) attract greater oviposition by stem borer moths. These grasses were used as trap crops in field trials to determine their effect on infestation pattern and severity of stem borer infestation of maize. Infestation by stem borers on the trap crops commenced four weeks after emergence of the maize crop. At flowering of maize the incidence of plants with stem borer damage was 34 % in blocks not surrounded by trap crops. Blocks surrounded by Napier grass and fodder sorghum had 18% and 48% damaged plants respectively. Napier grass as trap crop therefore significantly reduced stem borer infestation in maize. Other benefits of using these grasses in the farming system are that they can be used as fodder and also play an important role in reducing soil erosion.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA