Allylic and Non-allylic Alcohols Against the Maize Weevil (Sitophilus zeamais): A Promising Tool for its Control

Abstract

The maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), is a primary pest that mainly affects corn kernels during storage in silos. We evaluated the insecticidal activity by fumigation at 20 days and repellence of eleven allylic and non-allylic alcohols against S. zeamais and phytotoxicity of these compounds on corn kernels. Representatives of both groups, the allylic alcohols 1-octen-3-ol, trans-2-hexenol, and linalool and non-allylic alcohols 3-octanol and 1-hexanol showed high mortality values (> 72%) and repellency on maize weevils. A study of structure/activity relationship (QSAR) showed that the electric charge on carbon-bearing hydroxyl group is important in determining the insecticidal capacity. The tested alcohols generally did not cause a significant phytotoxic effect on grains. In conclusion, the compounds 1-octen-3-ol, linalool, 3-octanol, and 1-hexanol could be a good tool for S. zeamais control in silos because they induce high mortality, have the ability to repel insects, and are not phytotoxic to maize grains.