A Five-Component Plant-Derived Pesticide Blend Targeting Insect Pests, Fungal Pathogens, and Mycotoxin Contamination in Tree Nuts

Tree nuts (almonds, pistachios, and walnuts) are highly vulnerable to insect pests and mycotoxin-producing fungi, resulting in significant economic losses and food safety concerns. We evaluated plant-derived compounds, previously identified as semiochemicals in tree nut systems, as candidates for pesticidal development. Screening of analogs of 1-octen-3-ol and 2-phenylethanol identified sulcatone, phenylacetate, and acetophenone, while eucalyptol and pogostone were independently identified and incorporated into further studies. These compounds exhibited rapid, dose-dependent insecticidal activity against adult navel orangeworm ( Amyelois transitella ), causing mortality within minutes at 0.1–2.2%, and were also effective against carob moth and Carpophilus truncatus . A five-component blend demonstrated insecticidal efficacy comparable to that of its most active constituents. Acetophenone, phenylacetate, and pogostone inhibited the growth of mycotoxin-associated fungi, and pogostone reduced aflatoxin production in Aspergillus flavus at ≥400 μM. Together, these results demonstrate a multicomponent strategy for simultaneous control of pests and mycotoxin risk.