Monoterpenes: chemistry, insecticidal activity against stored product insects and modes of action - a review

New strategies have to be introduced for the management of agricultural and public health insects to overcome the problems associated with long-term use of synthetic insecticides. Plant-based natural products are among the possible and available alternatives to be applied for insect management. Among the plant secondary metabolites, monoterpenes have been widely studied for their applications in insect control. In this review, we focus on the studies describing the insecticidal and grain protection activities of monoterpenes against stored product insects. In addition, the biosynthesis and chemistry of monoterpenes as well as their possible modes of action and commercialization opportunities are summarized. The present review emphasizes the importance of monoterpenes as target-specific, biodegradable, environmentally safe grain protectants as well as their possible practical use as a tool in integrated pest management programs.