Atmospheric Cold Plasma (ACP) Treatment for Efficient Disinfestation of the Cowpea Weevil, Callosobruchus maculatus

Abstract

Highlights The exposure of C. maculatus to reactive gas species (RGS) from atmospheric cold plasma treatment (ACP) resulted in significant mortality at all life stages tested. Three-minute ACP treatments at voltages of 70 kV have the best insecticidal effect. The greatest impact of treatment was during the egg and young larval stages of C. maculatus. Abstract. The insecticidal capability and mechanism of high-voltage atmospheric cold plasma were studied using a dielectric barrier discharge reactor against Callosobruchus maculatus, a significant insect pest in stored grain degradation. The mortality rate of > 90.0% for egg and larval stages can be achieved with a longer treatment time of 3 minutes and a higher voltage of 70 kV. However, this treatment condition, paired with a post-treatment retention time of 4 days, is required to kill 95% of adult insects. The use of atmospheric cold plasma has a considerable impact on the mortality of a range of insect life stages. Sufficient toxicity can be achieved by plasma process management using modified atmospheric pressure with a working gas of 65% oxygen, 30% carbon dioxide, and 5% nitrogen to address the insect lifecycle phases that are vectors for pathogens, which can increase mycotoxin contamination and degrade grain quality. Introducing atmospheric cold plasma treatment as an alternative to chemical fumigation may provide a safer alternative for integrated pest management. Keywords: Atmospheric cold plasma (ACP), Cowpea weevil, Dielectric barrier, Insecticidal effect, Integrated pest management (IPM), Pesticide, Reactive gas species (RGS).