Preference of Major Stored Product Insects in Fortified Rice with Basil

Abstract

As the world’s population grows, the needs for feeding it follow the same path. Considering these conditions, ensuring the quantity and quality of raw materials, such as cereals, seems imperative. Stored product insects are responsible for significant losses in the post-harvest stages of agricultural products and the available chemical methods for their control are decreasing, due to their negative impact on the environment and humans. To this end, the evaluation of the efficacy of non-chemical methods for the management of storage insects is crucial. In the present study, we conducted two trials of choice tests based on rice fortified with basil to determine its potential as a non-chemical repellent of stored product insects. In the first trial, we evaluated the repellent activity of rice enriched with basil on adults of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Oryzaephilus surinamensis, as well as on T. castaneum larvae. In the second trial, the same procedure was followed with deltamethrin-treated rice fortified with basil. The results of the first trial showed that for most of the insect species tested, the rice fortified with basil was moderately repellent, while for O. surinamensis, it was attractive. Surprisingly, in the second trial, the deltamethrin-treated rice fortified with basil showed a repellent effect on O. surinamensis adults and T. castaneum larvae, while no repellency was observed for the rest of insect species examined. Observation time was not significant for any of the insect species, combinations and trials, with the exception of the rice fortified with basil vs. Blanc combination in O. surinamensis. Our findings suggest that the use of deltamethrin-treated rice fortified with basil was effective as a repellent for O. surinamensis adults and T. castaneum larvae.