insect-plant-coevolution
Insect-plant coevolution is the reciprocal evolutionary process by which plants and insects drive adaptations in one another over geological time, shaping traits such as plant defenses, pollination mechanisms, and insect feeding strategies. This dynamic is central to plant biology because it underlies the development of secondary metabolites, physical barriers, and signaling pathways that plants use to deter herbivores or attract beneficial insects. Understanding these coevolutionary relationships helps researchers decode the genetic and biochemical basis of plant resistance and mutualism, with direct applications in crop protection and breeding.
open_in_new WikipediaPubMed · 2026-05-01
Corn plants respond to caterpillar saliva by ramping up chemical defenses, but the type of response varies by species — even among closely related armyworms. The fall armyworm, a corn specialist, suppresses the plant's airborne distress signals while still triggering strong internal defense changes.
All three Spodoptera armyworm species triggered significant increases in phytohormone levels and defense gene expression in maize, indicating a broadly conserved plant immune response.
Despite similar internal hormone and gene responses, volatile emissions (airborne defense signals) were considerably lower when plants were treated with fall armyworm (S. frugiperda) secretions compared to beet armyworm and cotton leafworm.
The fall armyworm, a maize specialist, induced greater transcriptome-wide changes than the other two species, suggesting deeper co-evolutionary manipulation of the host plant's signaling pathways.
