This study aimed to evaluate the predatory effects of the primary insect pests Sitophilus zeamais and the secondary insect pests Orizaephilus surinamensis and Laemophloeus minutus in stored rice grains. The insect populations were kept under controlled conditions of temperature and photoperiod (20, 25 and 30 ºC, 14 h photophase) in five different infestation densities (0, 10, 20, 40, 80 and 120 individuals). The treatments were: S. zeamais isolated; O. surinamensis isolated; L. minutus isolated; S. zeamais + O. surinamensis and; S. zeamais + L. minutus. Analysis of rice grain damage occurred at 7 and 14 days after the beginning of the experiments, separating the insect pests from the grains. The largest losses occurred with increasing temperature and infestation density and the coexistence of S. zeamais + L. minutus produced the greatest predatory effects. It is concluded that lower temperatures as well as monitoring and control of infestation of primary and secondary insect pests reduces the loss of rice grains stored.
insect pests; coexistence; temperature; infestation density
