Fuente: PubMed "apiculture" Front Plant Sci. 2026 Jul 29;17:1867557. doi: 10.3389/fpls.2026.1867557. eCollection 2026.ABSTRACTINTRODUCTION: Agasicles hygrophila is a classical biocontrol agent widely used against the invasive weed Alternanthera philoxeroides. However, cotton aphid (CA) Aphis gossypii damage can alter host plant traits and reduce the fitness of A. hygrophila. The mechanisms underlying how aphid-damaged plant changes affect the behavior and physiological performance of this biocontrol agent remain unknown.METHODS: We investigated the effects of CA-damaged alligatorweed on the development, nutritional metabolism, oxidative defense, digestive physiology, and host-selection behavior of A. hygrophila. Larval growth parameters, nutrient composition, oxidative defense-related and digestive enzyme activities, and digestion-related gene expression were analyzed after feeding on CA-damaged alligatorweed. Feeding and oviposition preferences were evaluated using choice experiments. Gas chromatography-electroantennographic detection (GC-EAD), gas chromatography-mass spectrometer (GC-MS), and electroantennogram (EAG) analyses were conducted to identify behaviorally active volatile organic compounds (VOCs), followed by behavioral responses that were analyzed use the Y-tube olfactometer assays.RESULTS: Larvae feeding on damaged plants exhibited prolonged developmental durations and elevated mortality accompanied by diminished protein and lipid reserves but increased sugar content. Oxidative defenses were compromised, with significantly reduced activities of superoxide dismutase (SOD), catalase (CAT), and polyphenol oxidase (PPO). Digestive enzyme assays and qPCR analyses further revealed downregulation of trypsin and lipase activities, along with their encoding genes (AhTRY and AhLPS), whereas α-amylase activity and Ahα-AMY expression were markedly upregulated. Adult beetles showed a strong preference for feeding and ovipositing on undamaged plants over damaged ones. GC-EAD, GC-MS, and EAG analyses confirmed dose-dependent antennal responses to four VOCs. Behavioral assays demonstrated that oleonitrile, either alone or in combination with (+)-limonene, perillen or n-heptadecane, elicited strong repellency in adults.DISCUSSION: These results indicate that CA-damaged alterations in plant chemistry impair larval metabolism and oxidative defense systems while releasing repellent VOCs that deter adults, thereby compromising A. hygrophila's fitness and biocontrol efficacy against alligatorweed. These insights underscore the critical role of multitrophic interactions in refining biocontrol strategies for invasive weeds.PMID:42609831 | PMC:PMC13480174 | DOI:10.3389/fpls.2026.1867557