Comparative effectiveness of different modified atmospheres enriched with carbon dioxide and nitrogen on larval instars of almond moth Ephestia cautella (Walker) (Lepidoptera: Pyralidae)

The aim of this study was to determine the effectiveness of modified atmospheres (MAs) based on either high carbon dioxide (CO2) or high nitrogen (N2) contents at 30 °C in controlling all larval instars of the almond moth Ephestia cautella, a major pest of dried fruits. The tested MAs were 20%, 40%, and 60% CO2 in air, as well as 97% and 98% N2, with different exposure times. Results showed that the 1st, 2nd, 3rd, 4th and 5th instar larval mortalities of E. cautella responding to modified atmospheres (MAs) enriched with either CO2 or N2 increased significantly (P < 0.01) with increasing either exposure length or gas concentration. MAs enriched with CO2 were more effective than those containing N2. Three and six days were required to completely kill all larval instars with 60% CO2 and 98% N2, respectively. The 1st and 2nd instar larvae were more susceptible to all tested MAs than the later instars. It is recommended that MAs can be employed for controlling all larval instars of almond moth E. cautella.