Plant metabolites are making progress in the behavioral control of pests

Plants produce secondary metabolites that alter the behavior of insect pests. These compounds interfere with feeding, oviposition, and host selection. The effect reduces damage and pest populations.

Secondary metabolites act as allelochemicals. Compounds from the allomones group generate negative responses in insects. These actions include repellency, oviposition deterrence, and reduced leaf consumption. The result limits the establishment of the pest in the crop.

Four groups

Nearly 200 metabolites already described belong to four main groups: terpenoids, phenolic compounds, alkaloids, and sulfur compounds. This chemical diversity supports multiple modes of action. Terpenoids present in essential oils act as repellents or anti-feeding agents. Phenolic compounds reduce ingestion and can prevent egg laying. Alkaloids affect the nervous system of insects and also inhibit feeding. Sulfur compounds release toxic substances after tissue damage.

Phytophagous insects use chemical signals to locate hosts. Volatile compounds guide long-distance searches. Contact substances confirm the choice for feeding and oviposition. Plant metabolites alter these signals. This interference generates sensory confusion and prevents colonization.

Repellent action occurs through the emission of volatile compounds interpreted as negative signals. Monoterpenes such as linalool and cineole are among the main examples. These compounds prevent landing and feeding. Studies report an effect against aphids, whiteflies, and caterpillars.

Oviposition deterrence

Oviposition deterrence prevents egg laying. The mechanism includes masking attractive signals or emitting compounds associated with low nutritional quality. Plant extracts and essential oils demonstrate a significant reduction in oviposition in key pests.

Antifeeding action reduces or blocks tissue consumption. Compounds like azadirachtin affect taste receptors. The insect immediately stops feeding. The effect results in reduced larval growth and decreased fecundity.

Environmental advantages

Botanical insecticides based on these metabolites offer environmental advantages. Rapid degradation reduces residues. The diversity of modes of action decreases the risk of resistance. However, low persistence limits field efficiency. New formulations, such as nanoemulsions and encapsulation, seek to prolong their effect.

Challenges remain. Variability in chemical composition hinders standardization. Production costs exceed those of synthetic products. Regulatory processes restrict registration. Adoption depends on proven efficacy in the field and stability of formulations.

More information at doi.org/10.1016/j.tplants.2026.03.005