Exploration of Clove Bud (Syzygium aromaticum) Essential Oil as a Novel Attractant against Bactrocera dorsalis (Hendel) and Its Safety Evaluation

SIMPLE SUMMARY: Bactrocera dorsalis is among the most economically harmful pests. The lure-and-kill approach is an environmentally friendly and innovative method that offers an opportunity for sustainable surveillance and control of B. dorsalis. However, such a strategy requires highly effective pest attractants. In the current study, we compared the attractive activity of twelve flower essential oils against B. dorsalis adults via the indoor trapping assay. Meanwhile, we studied the attractive features of clove bud essential oil (CBEO) for males under laboratory conditions. Further, we also investigated CBEO’s attractancy to their natural predator, the ladybirds, and its cytotoxicity against non-target organisms’ cells. In particular, sexually mature males were dramatically attracted to the CBEO. Furthermore, the CBEO exhibited no significant attractancy to ladybirds nor cytotoxicity against normal human and mouse cells. The results revealed that CBEO shows potential for development as an eco-friendly and novel attractant agent for the control of B. dorsalis. ABSTRACT: The oriental fruit fly Bactrocera dorsalis (Hendel) is a destructive polyphagous species that targets many economically important fruits and vegetables. The primary control of B. dorsalis relies mainly on the use of synthetic chemicals, and excessive use of these chemicals has adverse effects on both the environment and human health. Environmentally friendly management of pests involving plant essential oils is useful for controlling the populations of pests responsible for decreasing the yields and quality of crops. In the present study, we demonstrate that clove bud essential oil (CBEO) is strongly attractive to sexually mature males. Mature males responded to the CBEO differently throughout the day; the strongest response was elicited during the day and decreased at dusk. Virgin and mated mature males did not respond differently to CBEO. No obvious response behaviour to the CBEO was observed in two species of beneficial natural predator ladybirds. In addition, a cytotoxicity assessment demonstrated that CBEO is nontoxic to normal human and mouse cells. Based on our laboratory experiments, CBEO may serve as a promising, sustainable, and environmentally friendly attractant for B. dorsalis males; however, field experiments are needed to confirm this hypothesis.