What Do Flour Beetles Look Like?

By Chris Williams on January 12, 2017.

I think I might have flour beetles infesting food in my kitchen cabinets. What do these beetles look like? I’ve found tiny brown things that look like beetles in a box of cake mix and a bag of cornmeal, so far. Did they come from the store or do I have a serious problem here? O. Y., Exeter, NH

You might or might not have flour beetles, and you might or might not have a serious problem. Not too helpful, I know, but the only way to answer these questions is with an inspection by a trained professional.

Flour beetles are indeed tiny, only about 1/8-inch long. They are brown, elongate oval in shape, and flattened, which allows them to get into even sealed food packages. Adult beetles can be found in the food, along with the wormlike larval stage, or they can be seen on the outside of infested food packages. They are active, running when disturbed, and are attracted to lights.

Food Pests Can Feed on Lots of Different Things

Like most food pests, flour beetles can feed on a variety of foods ranging from flour to cereal to spices. Not only is their presence in food objectionable, but flour beetles ruin flour and other foods by secreting chemicals that give the food a pinkish-gray tint and a characteristic bitter taste and musty smell.

Even if your food pests turn out not to be flour beetles, you no doubt have a similar food pest such as the sawtoothed grain beetle, cigarette beetle, or foreign grain beetle (see Flour Beetles Are Just One Type of Stored Food Pest).  Detection, prevention, and control for any of these food beetles is similar.

Your food beetles may have been already in the product when you purchased it, or the foods may have been infested after the fact by beetles already in your kitchen. Either way, your problem now is that you do have beetles in your cabinets that are poised to infest other products…and no food is immune from attack.

Find and Discard All Beetle-Infested Foods

The first step in dealing with food pests is to find and discard any infested, or potentially infested, foods (see How Can I Get Rid of Flour Beetles?). Sometimes infested foods can be frozen to kill the pests and then used but since flour beetles leave a bitter taste to the food, you’re better off tossing the products. Going through all of your food products looking for beetles or larvae can be a daunting job. If the food is not important to you, you might want to save yourself a step by tossing it and replacing it after treatment.

Start with foods that are the oldest, or packages forgotten on the back of the shelf, or packages that are torn or damp. Dump the contents onto a cookie sheet, spread it out, and look for adult beetles, beetle larvae, and shed skins (see How to Check Food Products for Insects – Advice From the Pros). Unfortunately, even unopened packages can be infested.

Our experts can help with this job and can advise you on how to prevent food pests in the future. In most cases, we would also treat your kitchen or pantry shelves to kill larvae that may hatch out later. Give Colonial Pest a call today!

Photo Credit : Public Domain, Link



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