Summary: Book lice populations can build up quickly in stored food products that have been left and forgotten at the back of your pantry shelves. You'll find yourself throwing away a lot of never-used food if you don't use some precautions.
Nathan; BC Canada asks:
I have found tiny bugs in my cupboards so small that they look like dust partials, but they move. I have removed everything from my cupboards and have cleaned with bleach, but even after 5 weeks I still keep finding them on the counter. How do I get rid of these little bugs? I believe they are called Liposcelis bostrychophila but I'm not totally sure.
Book lice are tough little guys to get rid of, but it can be done without pesticides. Somehow, your cabinets have a high humidity level that needs to be reduced. Here's the information you are seeking.
Liposcelis bostrychophila, also known as book lice, are part of the psocid family. There are small, soft-bodied insects that feed on mold, fungi found in grains and other starchy materials. Book lice usually avoid light and like to live in cracks and crevices where the humidity is fairly high such as enclosed spaces like cabinets. You don't often find them inside unopened packages of products shipped from the manufacturer, but they do have a habit of getting into broken or opened packages and containers.
Reducing the humidity below 50% will eliminate most infestations of book lice. Try to ventilate high moisture areas using a dehumidifier or a fan. Be sure to use a crack and crevic attachment on a vacuum cleaner to remove bits of food from the cracks of storage shelves. Don't overlook spilled foods like cereals and flour.
We are all guilty of pushing containers of food to the back of the shelf and forgetting about it. Foods stored for six months or more sometimes become infested especially in damp, dark, warm, undisturbed places. Try to rotate food products so that older items are used first. Check the manufacturing dates when you are going through your cabinets. Adult book lice populations tend to build up in greater numbers as the infestation ages. Put grain and cereal products in containers with tight fitting lids if the contents are not used within one week after opening. Place infested products inside plastic bags prior to disposal to reduce the spread of adult insects.