Smoke Waters affect behavior in the olive fruit fly Bactroera oleae

The smoke-waters (SWs) are secondary products obtained during the pyrolytic production of biochar. The study aimed to record the effects of the presence of SWs in a closed and open environment towards the behavior of the adults of Bactrocera oleae. The two more promising between 12 original SWs previously investigated were deeply evaluated in these assays. The in vitro assays were conducted in optimal condition of temperature relative humidity and light using a dynamic airflow glass Y-tube olfactometer. The positive controls were carried out using fresh green olives. SWs have shown attractive, repulsive or indecision effects depending on the starting raw materials they were produced of, and their dilution. The field assays have been carried out for two subsequent years in different pedoclimatic conditions (South and Central Italy), using kaolin clay and isopropyl-myristate as additional control due to their known repulsiveness. The SWs application’s efficacy was computed based on the number of catches of flying adults in chemo-chromotropic traps and on the level of infestation of the drupes at the harvest. Open-air trials, on both fields, shown expected attractive and repulsive effects of the SWs, consistently to those obtained in optimal and controlled environment during the olfactometry tests. Such results encourage further deepening studies to find promising new IPM strategies against B. oleae.