Modified Atmospheres as an Environmental Friendly Procedure to Control the Fennel Wasp Systole sp. (Hymenoptera: Eurytomidae)

This study aimed to evaluate different modified atmospheres as an environmental friendly procedure for controlling the fennel wasp Systole sp. The tested modified atmospheres (MAs) contained 10, 20, 30, 40, 50, 60, 70 and 80 % of carbon dioxide (CO2) in air as well as 97 and 98 % of nitrogen (N2). Heavy infested fennel seeds were exposed to these MAs at 15, 25 and 35 °C combined with different exposure periods. The wasp emergence from the infested seeds exposed to MAs decreased gradually by increasing the exposure periods, CO2 or N2 contents and temperatures. MAs containing CO2 were more effective than those containing N2based on the reduction of the adult emergence. Complete reduction in emergence (100 % ) of CO2 treatments was recorded with 60, 70 and 80 % of CO2 at 35°C after 15 days of exposure. Meanwhile, in case of 97 and 98 % of N2, 25 days of exposure were needed to reach zero emergence at 25 and 35 °C. No effect was observed on the emergence of adult wasps from the infested seeds that were exposed to MAs containing 97 or 98 % of N2 at 15 °C. It is recommended to use at least 60–70 % of CO2 for 15 days and 97–98 % of N2 for 25 days at 35°C for controlling Systole sp.