LAUSR

BACKGROUND The application of allyl isothiocyanate (AITC) has been proposed as an alternative to control stored-grain insects. However, AITC is a compound with a low diffusion coefficient, making its distribution throughout the grain mass difficult. Therefore, the objective of the present study was to evaluate the effectiveness of AITC applied in systems with or without recirculation for controlling Sitophilus zeamais (Mots. 1855) (Coleoptera: Curculionidae), Rhyzopertha dominica (Fabr.) (Coleoptera: Bostrichidae), and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) infesting a corn grain mass. The assays used a PVC prototype, dimensioned 1.60 m in length, 0.30 m in diameter, and a static capacity of 60 kg of grains. AITC toxicity to insects was evaluated at the base, 0.5 m from the base, and top of the grain column (1.0 m). Different concentrations of AITC were tested for an exposure period of 48 h. RESULTS In the system without AITC recirculation, insect mortality was verified only at the base of the grain column. On the other hand, insect mortality was considered uniform at the different positions of the column when the AITC recirculation system was adopted. In this system, there was also a marked reduction in the instantaneous population growth rate of S. zeamais, T. castaneum, and R. dominica, and a decrease in the dry matter loss of the grains, when the AITC concentrations were increased. CONCLUSION AITC recirculation proved to be a viable strategy for protecting grains against the species S. zeamais, R. dominica, and T. castaneum. AITC fumigation ultimately did not cause changes in grain quality. This article is protected by copyright. All rights reserved.