Effects of Smoke Waters on Bactrocera oleae

The pyrolysis of organic feedstock yields the biochar, bio-oils, and a volatile fraction that can be reused for technological applications in agro-ecosystems in the form of smoke-water (SW). This study examined the effects on Olive Fruit Fly (OFF - Bactrocera oleae) of 10 different SWs obtained at 300 °C and 500 °C (pyrolysis temperatures) from cellulose, wood sawdust, olive mill residues, maize, and alfalfa litter. The assays were conducted at two different concentration using a dynamic airflow glass Y-tube olfactometer and the results were compared with a positive control of fresh green olives. Data concerning the selective choices of B. oleae were statistically analyzed using the χ2 test (P < 0.05). The analysis of the data show that the volatile compounds of SW significantly modified the behavior of B. oleae. A strong repulsive effect has been recorded with the two dilutions of SW from cellulose obtained at 300 °C (50% for males and 60% towards females) and wood sawdust at both temperatures ranging from 50% up to 70% depending on sex and SW concentrations. Further studies are ongoing to confirm the repulsive effect in semi-field and open-air tests, and to complete the chemical and biological characterization of the active volatile organic compounds (VOCs).