Nonchemical dielectric barrier discharge treatment as a method of insect control

The spread of insects due to trade of agricultural commodities and travel of humans is a significant problem in many countries. Limiting the movement of pest species is commonly achieved by the use of chemical pesticides. Concerns about resistance to insecticides, as well as their environmental impact has stimulated an evaluation of alternative pest control methods. Nonchemical dielectric barrier discharge (DBD) treatment of insects in a low electron density (10⁶-10⁸ cm^-3), low electron temperature (1-2 eV) discharge has proven effective in significantly reducing the population of selected insects. The insects are directly exposed to a wide gap (>3 cm) helium discharge with average power densities on the order of 60 mW/cm³. Direct measurement of chemical species and ambient gas temperature shows the DBD treatment remains effective when the chemically reactive species are suppressed by helium, and when the ambient gas temperature of the discharge is below 40°C. However, the treatment is more rapid when the ambient gas temperature is elevated. The study has shown the treatment does not always induce instant mortality: however, the mortality increases over a 24-h period after treatment.