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.

Cowpea, Vigna sp., is an important, low-cost protein source in subtropical and semi-arid regions, where seasonal rainfall makes storage necessary. However, the weevils Callosobruchus maculatus and C. chinensis cause significant grain losses during storage. While synthetic fumigants are commonly used to control these pests, their risks to mammals have prompted the search for safer alternatives. In this context, we tested palo santo, Bursera graveolens, essential oil with limonene, α-phellandrene, o-cymene and β-phellandrene, menthofuran, and germacrene-D as a sustainable approach. This plant is readily accessible, produces high fruit yields, and is used in households for various purposes. We evaluated the fumigant toxicity, repellency, and ovicidal effects of B. graveolens essential oil on both Callosobruchus species. Our results showed that B. graveolens oil was toxic to C. maculatus (LC₅₀ = 80.90 [76.91–85.10] µL) and C. chinensis (LC₅₀ = 63.9 [60.95–66.99] µL), with C. chinensis being more susceptible (SR = 1.27). Molecular docking analyses revealed that all the oil’s compounds bind to both the GABA and octopamine receptors, exhibiting high energy affinities; however, germacrene shows the strongest affinity in these receptors. C. chinensis was strongly repelled at all concentrations, while C. maculatus was repelled only at lethal concentrations. No ovicidal effect was observed in either species. In conclusion, our findings suggest that B. graveolens essential oil is a promising and sustainable protectant for stored cowpeas in small-scale storage units.

Ruta chalepensis (Rutaceae), commonly known as rue, is traditionally recognized for its medicinal applications and cultural associations with mysticism. In addition to its ethnobotanical relevance, R. chalepensis has been reported to possess insect-repellent and pesticidal properties. However, domestication and the adoption of monoculture practices can compromise inherent plant defenses, potentially increasing susceptibility to herbivore pressure. In this context, we report, for the first time, the occurrence of infestations by the highly polyphagous aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) on R. chalepensis cultivated under Neotropical conditions. The infestations were documented in commercial rue fields located in the Zona da Mata region, Minas Gerais, Brazil, in two consecutive years. Plant material was taxonomically verified and deposited in the VIC Herbarium at the Universidade Federal de Viçosa. Aphid specimens, including both apterous and alate morphs, were examined under a stereomicroscope to confirm species identity. Field sampling revealed a notable interaction between M. persicae and native natural enemies, particularly predatory spiders. Aphid density per plant declined markedly from 14.1 to 6.2 individuals, coinciding with an observed increase in spider activity. These findings expand our understanding of M. persicae’s ecological plasticity and highlight the vulnerability of non-conventional crops to generalist pests. They also underscore the importance of implementing targeted pest surveillance and integrated pest management (IPM) approaches in underutilized or alternative cropping systems.