Sitophilus oryzae, Tribolium castaneum, Tribolium confusum, Oryzaephilus surinamensis, Rhyzopertha dominica, Tenebrio molitor, Trogoderma granarium, Acarus siro, and Alphitobius diaperinus represent significant arthropod stored-product pests worldwide. To combat these noxious arthropods, the current study examines the pesticidal effect of essential oils (EOs) derived from four aromatic plants, i.e., Illicium verum Hook. F., Citrus reticulata Blanco, Monodora myristica (Gaertn.) Dunal, and Xylopia aethiopica (Dunal) A. Rich. Considering the challenge of pesticide resistance, the current study focuses on assessing the efficacy of these EOs as an eco-friendly alternative to traditional synthetic insecticides. Two EO concentrations (500 and 1000 µL/kg wheat) were applied to different life stages of these pests in the bioassays. Mortality rates were monitored over several days under controlled environmental conditions. The findings demonstrated that C. reticulata and I. verum EOs had elevated insecticidal effects, especially against larval stages, resulting in 100% mortality in several species. On the contrary, M. myristica and X. aethiopica EOs showed less overall efficacy despite their potency against some pests. Both I. verum and C. reticulata EOs outperformed the positive control, pirimiphos-methyl, in several assays. The results of the current study highlight the potential of several EOs as effective alternatives in reducing synthetic pesticide use for integrated pest control management.

Tetranychus urticae (Acari: Tetranychidae) is a pervasive and damaging mite pest of tomato crops, leading to important economic losses globally. This study evaluated the acaricidal efficacy of spinosad, alone and in combination with Beauveria bassiana (Bb) WG-21 and Metarhizium robertsii (Mr) WG-04, in the laboratory (application to tomato leaf discs) and greenhouse (application to tomato plants), considering mortality and establishment, respectively. The combination treatments of Bb WG-21 or Mr WG-04 with spinosad achieved 100% mortality of T. urticae nymphs within 2 days on leaf discs, while individual applications of each control agent resulted in lower mortalities, ranging between 62.91 and 86.25% after 3 days. The paired treatment of Mr WG-04 + spinosad killed all exposed adults within 5 d, while that of Bb WG-21 + spinosad achieved the same results after 7 d. However, spinosad, Mr WG-04, and Bb WG-21 alone killed ≥77.08% of adults after 7 d. In the greenhouse, the combination treatment of WG-04 + spinosad deterred the presence of T. urticae (adults, immatures, and eggs) on either surface of the tomato leaves, while Bb WG-21 + spinosad suppressed the populations only on the adaxial surface. These findings indicate that combined treatments of the tested EPF + spinosad, especially Mr WG-04, on tomato plants under greenhouse conditions can provide substantially enhanced control of T. urticae life stages compared to each treatment applied alone.

Storage insects consist a continuous global threat to food safety. In this study, the efficacy of the entomopathogenic nematodes (EPNs) Steinernema khuongi and Heterorhabditis downesi was evaluated against larvae of Tribolium castaneum, Tribolium confusum, Tenebrio molitor, and Trogoderma granarium in wheat and maize at six concentrations and two exposure intervals. Both EPNs exhibited higher virulence when applied in wheat than in maize. Generally, larval mortalities were higher under H. downesi treatments vs. S. khuongi, both in commodities and exposures. Notably, the tested EPNs caused high mortalities to T. granarium larvae (range, 88.9–92.2%) and T. castaneum larvae (range, 81.1–94.4%), respectively, at 10,000 IJs/mL in wheat vs. mortality ranges 72.2–77.8% and 74.4–87.8% in maize, respectively. In contrast, T. confusum larvae were tolerant to both EPNs. Tenebrio molitor larvae were tolerant to S. khuongi (83.3% mortality) at 10,000 IJs/mL in wheat and maize. These findings highlight the potential of S. khuongi and H. downesi as beneficial organisms against several stored-product insect pests.