Electrospun nanofibers as novel carriers of insect pheromones:communication disruption strategy against Lobesia botrana

Abstract: Using organic nanofibers as dispensers for pheromones and kairomones in plantprotection for disrupting insect chemical communication is a novel approach aiming at popularizingthis technique in organic and integrated plant production. Expected advantages of the nanofibers arehighly controlled spatiotemporal release rates of pheromones / kairomones, improved climaticstability, and mechanized application. Dispenser types used so far show deficiencies in one or moreof these requirements. Mechanical application of pheromone dispensers is a new approach toreduce the costs of manual labour. Therefore the environmentally compatible, highly specific andefficient technique of mating disruption may become an alternative to the use of synthetic pesticidesin integrated pest management. The electrospun nanofibers are highly elastic, which preventsbreak-off of smaller pieces, and polymers used are biocompatible. Due to the tiny scale ofnanofibers the mass input both for pheromones and for polymeric nanofibers is extremely low.Major environmental benefits are high control specificity, very low concentrations of residues andminimal risk towards development of resistant insect strains. We tested organic polymer fibers,made from the biodegradable polymer Ecoflex® (BASF), treated with Lobesia botrana(Lepidoptera: Tortricidae) sex pheromone, (E,Z)-7,9-dodecadienyl acetate, in cage tests placedinside vineyards. With this experimental setup it is possible to show the applicability of matingdisruption dispensers for the use in plant protection against insect pests in vineyards. We usedIsonet LE dispensers (Shin-Etsu) as a positive control. The Ecoflex® nanofiber-pheromonedispensersshow a mating disruption effect which is comparable to the efficacy of the Isonet LEdispensers for at least three weeks. After that, the mating disruption effect observed tapers off to alevel where it is insufficient for plant protection purposes. But, in principle, our first prototype of ananofiber pheromone dispenser has proved its efficacy for mating disruption purposes.Modifications of the fibers, currently under development, open up the possibility of extending thedisruption effect to a period of several months’ duration, enough to cover the entire flight period ofLobesia.