Potential Use of Terpenoids for Control of Insect Pests

Essential oils (EOs) have diverse chemical compositions depending on the plant species used, but the most common constituents present in EOs are mono- and sesquiterpenoids. Such volatile terpenoids have different functions in plant ecology, acting, for example, as chemical defenses against fungi, bacteria, and insects, attracting pollinators, inhibiting germination, and mediating intra- and interspecific plant communication. Mainly terpenoids present the ability to inhibit the main families of detoxifying enzymes of insects, allowing the formulation of botanical insecticides, and using blends of EO compounds considered synergists among themselves. In this case, both combinations of essential oils from different plants and the enrichment of essential oils and/or their fractions with compounds with proven synergistic effects can be considered. This chapter presents research results that indicate synergistic, additive, and antagonistic interactions between terpenoids, indicating that this is one of the main properties considered when formulating insecticides based on commercially available EOs. Considerable advances are still necessary for large-scale production, and limitations related to raw material supply, registration, and, mainly, adequacy of formulations for the control of different targets without phytotoxic effects, are the main challenges to be overcome in the short-term