Extracts of Pimenta dioica, Callistemon citrinus and Syzygium malaccense on Sitophilus oryzae

There are several products that have been used for the control of Sitophilus oryzae L. However, the high resistance of the insect to various chemical products has motivated the search for new alternatives for its control, which led to evaluating the in vitro effect of the extracts from Pimenta dioica (L.) Merr, Callistemon citrinus (Curtis) Skeels and Syzygium malaccense (L.) Merr. & L.M. Perry on S. oryzae. The plant material was ground into particles smaller than 1 mm. The powder obtained was used to obtain extracts through three extraction methods (Soxhlet, assisted extraction with Ultrasound and Maceration), with n-hexane, ethyl acetate and methanol solvents. The yield of the extracts was determined and the biological action on S. oryzae was evaluated by means of the percentage of insect emergency mortality and weight loss. The extracts formed by Soxhlet and n-hexane were more effective in vitro on S. oryzae, but all showed high repellency.