Temperature and Pantry Pest Control
When packages of food are found to be infested with pantry moths or pantry beetles, either low or high temperatures may be used to control the infestation. Insects are cold-blooded; their body temperatures closely follow that of their environment.
The most favorable temperature for most pantry pest is about 80°F. Above 95°F or below 60°F, reproduction and survival is greatly reduced.
When temperatures are lowered, insect activity decreases until all activity stops. The quicker the drop in temperature, the quicker the kill. Although insects will be killed, their bodies will remain in the food unless sieved out.
An exposure of 2 to 3 days to temperatures of 5°F or lower kills the susceptible stages (larvae and adults), but eggs require longer to kill (3-4 weeks).
An alternative is to freeze the food for a week, remove it from the freezer for a few days, and then refreeze it for another week.