Comparative efficacy of modified atmospheres enriched with carbon dioxide against Cadra (=Ephestia) cautella.

BACKGROUND

Cadra (=Ephestia) cautella (Walker) is a serious cosmopolitan pest that can feed on a wide variety of stored foods. It is controlled mainly by fumigation with phosphine, to which strong resistance has been documented in major stored-product insects in many countries. The need for reliable, user- and environmentally friendly alternatives is therefore high on the agenda to avoid the development of potential resistance and to reduce human exposure to toxic insecticides. Two modified atmospheres (MAs) composed of high carbon dioxide (CO ) and low oxygen (O ) (90% and 96% CO in air) were studied at the laboratory at 20 °C and 65 ± 3% relative humidity (RH) against C. cautella.

RESULTS

Eggs (1, 2, and 3 days old), young and mature larvae (10 and 20 days old), pupae (1, 2 and 3 days old) and adults (1 day old) were exposed to two MAs consisting of high CO and low O for the range of 2 to 104 h. Eggs, old larvae, and pupae were found to be the most tolerant. Adults were rather easily killed and young larvae were the most susceptible. Lethal exposure time (LT ) values were between 11.74 h and 128.97 h.

CONCLUSION

Modified atmospheres consisting of high CO and low O offer an affordable combination to control C. cautella effectively. From the perspective of economics and efficacy, 90% CO might be the concentration of choice. © 2019 Society of Chemical Industry.