The grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae), is a pest that causes significant economic losses in vineyards worldwide, and its impact is expected to increase in the coming years as a result of global temperature rise. The IN-vid research group is working on the development of a new control strategy based on the use of volatile organic compounds (VOCs) of bacterial origin.
In this study, the effect of compounds produced by two bacterial species, Xenorhabdus nematophila and Photorhabdus laumondii, both known for their symbiotic association with nematodes of the Steinernema and Heterorhabditis genera, respectively, was evaluated. Specifically, the impact of these VOCs on the ovipositional behavior of the moth and on the choice of food sources for larvae was investigated. In addition, bacterial ferments with different fermentation times (3 and 5 days) and two different application systems were tested: contact application of the ferments on the grape and exposure of the grape to the VOCs emitted by the ferment.
The results showed that the efficacy of this new biotechnological tool depended on the bacterial species used and the fermentation time of the bacteria. Grapes treated with 3-day fermentations of X. nematophila and P. laumondii registered fewer eggs than control grapes, with a reduction of up to 95%. In addition, the VOCs emitted by 5-day P. laumondii fermentations prevented the ovipositional activity of the moth by 100% for three days. Finally, both bacteria demonstrated deterrent effects on larval feeding, with a reduction of up to 65% in the choice of treated grapes compared to controls.
This research lays the groundwork for the development of alternative, ecological, and cost-effective tools for the control of grapevine moth and other pests, thus contributing to the increasing reduction of chemical pesticide use.
For more info, see:
Vicente-Díez, I., Pou, A., Campos-Herrera, R., 2023. The deterrent ability of Xenorhabdus nematophila and Photorhabdus laumondii compounds as a potential novel tool for Lobesia botrana (Lepidoptera: Tortricidae) management. Journal of Invertebrate Pathology, in press.