Natural Products: Are They Efficient Alternatives against the Stored Grain Pest Sitophilus zeamais?

Cereal crops strongly contribute with the world economy and because of this the reduction of their productivity may lead to irreparable economic consequences worldwide. The maize weevil Sitophilus zeamais is the main pest of maize in the field or during processing, storage and commercialization of grains, also attacking processed food. The population control of S. zeamais uses a restrict panel of synthetic insecticides which are associated with environmental contamination, selection of resistant individuals and toxicity to non-target organisms, including humans and other animals. This scenario has stimulated the search for new insecticides and plant metabolites stand out because of their high degree of biodegradability and more selective toxicity. This work provides a review of the effect of plant compounds on S. zeamais to encourage the use of these ingredients in more ecofriendly strategies for pest control. Plant insecticides can exert their toxicity by ingestion, contact and/or fumigation resulting in damage to the development, survival and reproductive potential of S. zeamais, or may present food deterrent activity, which protects the substrates from the attack by the insects. The data reviewed contribute to consolidate the use of natural products in control of S. zeamais.