Insect control with CO₂ in a small stack of bagged grain in a plastic film enclosure

Abstract

The use of carbon dioxide, added as dry ice, was demonstrated as a means of disinfestation of bagged wheat and rye enclosed in a PVC membrane. The bag stack was dosed with dry ice giving an atmosphere of about 60% CO2. Carbon dioxide levels were maintained over 22 days with additional charges of dry ice added directly on top of the stack or enclosed within a polystyrene box to regulate the CO2 release rate. A natural infestation of Rhyzopertha dominica with small numbers of other stored product pest species was controlled, with complete mortality of adult insects, but slight survival of some early stages of R. dominica. Some of the hymenopterous parasitoids, Anisopteromalus calandrae and Choetospila elegans, survived the treatment, apparently as pupae. The treatment was successful under conditions where many other methods of pest control were inapplicable because of difficulty or expense of application, as in a small bulk (2.8 tonnes), at low temperature (11-13¦C), when the commodity is close to working areas and when there is a requirement for freedom from pesticide residues.