Termite Abundance and Damage in Traditional Maize–Cassava Intercrops in Southwestern Nigeria

During surveys conducted in 40 maize-cassava intercrops in the humid forest zone of southwestern Nigeria, the following termite species were identified from soil samples: Microtermes spp., Macrotermes nigeriensis (Sjostedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) and Anoplotermes quietus (Fr. Muller). High incidence of Microtermes and Macrotermes spp. was observed. The population density of predominant species was generally higher in the rainy seasons than in the dry seasons, indicating the role of moisture in their spread. The soil texture of surveyed farms did not influence the presence of the subterranean species Microtermes. The level of weeds in the surveyed farms also did not affect the population density of termites. However, Microtermes population increased significantly (P < 0.05) with increase in crop residues and its presence in farms partly depended on the presence of maize in such farms. Microtermes and Macrotermes species inflicted most of the damage observed on maize crops, while that caused by Amitermes evuncifer waslow. No termite attack was observed on growing cassava during the surveys. The presence of live cassava in the intercrop did not influence damage by termites. Nasutitermes and Microcerotermes species which attack economic trees such as cocoa, citrus, oil palm, and forest trees did not attack cassava or maize.