EFFECTS OF TIME OF DAY AND SEED WEIGHT ON THE FORAGING ACTIVITY OF THE HARVESTER ANT (Messorga a Forel) AND CROP LOSSES ASSOCIATED WITH ITS INFESTATION IN THE NIGERIAN SUDAN SAVANNA

Studies an tire effects of time of day and seed weight on the foraging activity of the harvester ant (Messgr galla Forel) were conducted during the rainy season in Maiduguri, Northeastern Nigeria (Latitude 1 1 53' N and Longitude 3 16' E) from July to September, 1997, Losses of groundnut pods and haulm were also assessed. More ants left’.their nests than those returning with food, although the difference was not significant (P • 0.05). Foraging occurred mostly in the mornings and evenings and not during the hot afternoons. Running speed of the ,ants was significantly reduced as the load-size increased. Crop losses incurred on a 142 m3 area of farmland amounted to 13.8 kg' of groundnut pods and 5'1.8 kg of haulm, respectively, and these were valued at N1657.Q and N 136.9 respectively. The implications of these findings foi chemical control are discussed.