If there are bugs in your flour and cornmeal, then it points to the presence of pantry moths or weevils. In order to keep the pantry moth or weevils away, it is recommended to do a good housekeeping as a measure of prevention in first place. Both the moths and weevils do not like clean surroundings so if you want to protect your pantry, you need to minimize the accessibility of food to these bugs. You should always check for infestation by examining all food packages for various signs of moth or weevil infestation. It includes webbing in corners, small holes in containers or clumping of grains together with sticky secretions.
In case, you spot an infestation, you should clean the infested areas with Vacuum cupboards. After that you should scrub all shelves with soapy water thoroughly and pay close attention to cracks as well as corners. You should also dry the cleaned area completely and always try to maintain the cupboard and food-storage areas dry. You should immediately discard the infested food. You also need to look for little moths flying around the kitchen or small bugs in the food.
You need to store the food properly and clean containers with hot and soapy water. After that you should rinse and dry them completely prior to refilling it. You should use tightly sealed glass, metal or hard plastic containers for storing the food. You should avoid the plastic bags as they are insufficient as insects can make their way through them. You should separate the old and new food from each other. Also, keep the not so used items in the freezer. You should eliminate the pest’s food sources and breeding grounds. You should not try to use pesticides in any area where the food is prepared or kept.