Extremely low neonicotinoid doses alter navigation of pest insects along pheromone plumes

Despite the prevailing use of neonicotinoids in pest control, and their known adverse impact on non-target organisms like honeybees, relatively few studies have explored the effect of sublethal neonicotinoid levels on olfactory responses of pest insects, and thus their potential impact on semiochemical surveillance and control methods, such as monitoring or mating disruption. We recently reported that sublethal doses of the neonicotinoid thiacloprid (TIA) had dramatic effects on sex pheromone release in three tortricid moth species. We present now effects of TIA on pheromone detection and, for the first time, on navigational responses of pest insects to pheromone sources. TIA delayed and reduced the percentage of males responding in the wind tunnel without altering pheromone detection at the antennal level. During navigation along an odor plume, treated males exhibited markedly slower flights and, in general, described narrower flight tracks, with an increased susceptibility to wind-induced drift. All these effects increased in a dose-dependent manner starting at LC0.001 -which would kill just 10 out of 106 individuals- and revealed an especially pronounced sensitivity in one of the species. Our results suggest that minimal neonicotinoid quantities alter chemical communication, and thus could affect the efficacy of semiochemical pest management methods.Dades primàries associades a un article publicat a la revista Scientific Reports disponible a l'adreça https://doi.org/10.1038/s41598-019-44581-