The γ-aminobutyric acid (GABA) receptors play pivotal roles in the transmission of neuronal information in the nervous system of insects, which has led these proteins to be targeted by synthetic and natural products. Here, we assessed the insecticidal potential of the essential oil of Pectis brevipedunculata (Gardner) Sch. Bip., a neotropical Asteraceae plant used in traditional medicine, for controlling Drosophila suzukii (Matsumura) adults by feeding exposure. By using in silico approaches, we disentangle the contribution of GABA receptors and other potential neuronal targets (e.g., acetylcholinesterase, glutathione-S-transferases) in insects that may explain the essential oil differential activities against D. suzukii and two essential pollinator bees (Apis mellifera Linnaeus and Partamona helleri Friese). Neral (26.7%) and geranial (33.9%) were the main essential oil components which killed D. suzukii with an estimated median lethal concentration (LC₅₀) of 2.25 µL/mL. Both pollinator forager bee species, which would likely contact this compound in the field, were more tolerant to the essential oil and did not have their diet consumptions affected by the essential oil. Based on the molecular predictions for the three potential targets and the essential oil main components, a higher affinity of interaction with the GABA receptors of D. suzukii (geranial −6.2 kcal/mol; neral −5.8 kcal/mol) in relation to A. mellifera (geranial −5.2 kcal/mol; neral −4.9 kcal/mol) would contribute to explaining the difference in toxicities observed in the bioassays. Collectively, our findings indicated the involvement of GABA receptors in the potential of P. brevipedunculata essential oil as an alternative tool for controlling D. suzukii.

Social insect pests such as leaf-cutting ants challenge conventional pest management because effective control must disrupt colony-level organization rather than target individual insects. Colony persistence depends on the mutualistic association between gardener workers and their cultivated fungus, Leucoagaricus gongylophorus. Compounds that selectively impair these components while preserving forager-mediated bait transport may therefore offer strategic advantages. We evaluated the essential oils of weeping willow (Salix babylonica), Surinam cherry (Eugenia uniflora), weeping bottlebrush (Melaleuca viminalis), ginger (Zingiber officinale), and black pepper (Piper nigrum) against two leaf-cutting ant species, Atta sexdens and Acromyrmex subterraneus, after characterizing their chemical composition by GC–MS. The oils displayed distinct terpenoid profiles: bottlebrush oil, for instance, was dominated by 1,8-cineole and α-pinene, while ginger oil was rich in camphene and β-phellandrene. Forager and gardener workers were tested separately, along with their symbiotic fungus. Responses were generally concentration-dependent, although effects varied among oils and biological targets. Ginger oil exhibited strong fungicidal activity, but only at the highest concentration tested (100 mg mL⁻¹). Bottlebrush oil showed marked toxicity to A. sexdens gardeners at concentrations as low as 0.10 mg mL⁻¹, while effects on foragers were comparatively low. The remaining oils produced limited or inconsistent responses. These findings indicate that caste-selective toxicity and fungal suppression are achievable but not widespread among essential oils. Bottlebrush oil emerges as a promising candidate for further investigation, particularly regarding its constituent compounds and potential synergistic interactions for toxic bait development.