The widespread use of synthetic chemical pesticides beginning in the late 1930s has contributed to the development of insecticide resistance of many important species of pest insects and plants. Recent trends in pesticide development have emphasized the use of more environmentally benign control methods that take into consideration environmental, food safety, and human health. Biopesticides (e.g., naturally occurring pesticidal compounds) are alternative pest management tools that normally have no negative impact on human health or the environment. Here we review methyl benzoate, a relatively new botanical insecticide that occurs naturally as a metabolite in plants, and whose odor is an attractant to some insects. Since 2016, many studies have shown that methyl benzoate is an effective pesticide against a range of different agricultural, stored product, and urban insect pests. Methyl benzoate has several important modes of action, including as a contact toxicant, a fumigant, an ovicidal toxin, an oviposition deterrent, a repellent, and an attractant. In this review, we summarize various modes of action of methyl benzoate and its toxicity or control potential against various kinds of arthropods, including agricultural pests and their natural enemies, and pollinators. We conclude that methyl benzoate is a very promising candidate for use in integrated pest management under either greenhouse or field conditions.

Safer alternatives to synthetic pesticides are essential for sustainable agriculture. Methyl benzoate (MB) is a volatile essential oil found in several plants. Recent reports of the toxicity of MB to arthropod pests suggest that MB may be a useful alternative insecticide. The present study assessed the effects of a sublethal concentration of MB (LC₃₀, 0.22%) on the life history and reproductive characteristics of the cotton aphid, Aphis gossypii Glover, in both a treated parental generation (F₀) and untreated progeny (F₁). MB treatment significantly decreased longevity and fecundity in both the F₀ and F₁ generations, and prolonged the developmental duration of each immature instar of the F₁ generations, compared with controls. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀) of the F₁ generation were significantly reduced, compared to controls. The mode of action of MB is not known, but in aphids treated with LC₃₀ MB, the activity of the enzyme acetylcholinesterase (AChE) decreased by more than 65%, compared with untreated controls. AChE activity was rapidly inhibited within 1 h, and remained inhibited for 6 h after in vivo exposure to MB. Moreover, molecular docking analysis revealed that MB had a strong affinity with the catalytic site of AChE, with a binding energy value of −6.2 kcal/mole. Our results suggest that MB targets AChE, and that a sublethal dose of MB can have adverse transgenerational effects on cotton aphids.

The Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is an insect pest that commonly affects stored and postharvest agricultural products. For the control of insect pests and mites, methyl benzoate (MBe) is lethal as a fumigant and also causes contact toxicity; although it has already been established as a food-safe natural product, the fumigation toxicity of MBe has yet to be demonstrated in P. interpunctella. Herein, we evaluated MBe as a potential fumigant for controlling adults of P. interpunctella in two bioassays. Compared to the monoterpenes examined under laboratory conditions, MBe demonstrated high fumigant activity using a 1-L glass bottle at 1 μL/L air within 4 h of exposure. The median lethal concentration (LC₅₀) of MBe was 0.1 μL/L air; the median lethal time (LT₅₀) of MBe at 0.1, 0.3, 0.5, and 1 μL/L air was 3.8, 3.3, 2.8, and 2.0 h, respectively. Compared with commercially available monoterpene compounds used in pest control, MBe showed the highest fumigant toxicity (toxicity order as follows): MBe > citronellal > linalool > 1,8 cineole > limonene. Moreover, in a larger space assay, MBe caused 100% mortality of P. interpunctella at 0.01 μL/cm³ of air after 24 h of exposure. Therefore, MBe can be recommended for use in food security programs as an ecofriendly alternative fumigant. Specifically, it provides another management tool for curtailing the loss of stored food commodities due to P. interpunctella infestation.

Benzoates (naturally occurring plant toxins) produce pesticidal effects on various pest insects and mites, but their effects on non-target insects are poorly understood. In this study, we evaluate the lethal and sublethal toxicity of methyl benzoate (MB) to adults of the generalist predatory bug Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae). To assess lethal effects, N. tenuis was exposed to plant surfaces treated with 0.25%, 0.5% and 1% MB, as well as negative and positive controls (water and the neonicotinoid acetamiprid, respectively). Exposure to 1% MB resulted in the highest corrected mortality of 17.8% and 13.3% under laboratory and greenhouse conditions, respectively. Thus, 1% MB can be classified as harmless to N. tenuis according to the International Organization for Biological Control rating scheme. At the sublethal level, MB exposure did not significantly affect the consumption of eggs of the whitefly Bemisia tabaci by N. tenuis relative to negative control feeding rates. In contrast, acetamiprid at the manufacturer’s recommended concentration reduced N. tenuis feeding activity by 45.4%. Furthermore, in a Y-tube olfactometer assay, there were no significant differences between the olfactory responses of N. tenuis to MB concentrations and the negative control (water). This study therefore suggests that MB could be used safely for pest control in combination with N. tenuis.

The efficacy of lemon-scented tea tree oil (LSO), Leptospermum petersonii (FM. Bailey), was evaluated against the diamondback moth, Plutella xylostella (L.) und