Flour mites and flour weevils are the most common pests that you can find in your pastries. Both of those are feeding on the dry foods stored in our cupboards. They prefer dark, humid places with lots of supplies.
By this point, you probably noticed that we are talking about two different pests. Flour mites and weevils are two completely different species. However, when you are searching for “bugs in flour” you get many answers for both of them.
Let’s see how to tell them apart, so we can establish what are we dealing with.
What do flour mites look like
Flour mites are very small almost impossible to see, especially in flour. Their bodies are white with light brown legs. There are many different species of flour mites, also known as grain mites and kitchen mites, but they all look similar, especially to the naked, untrained eye. The size of the mites ranges from 0.33 to 0.66 mm in length.
What do weevils look like
The weevils look like beetles. After all, they are a beetle and categorise with the same oval shapes. Weevils are bigger than flour mites and with darker bodies. The body of the flour weevil is dark brown, making them easier to spot. They are also larger in size, from 3 to 10mm in length. Considerably bigger than flour mites. Weevils are well known for their snout shaped nose, you can easily tell them apart from any other insect thanks to it.
As it happens with many other pests like bed bugs and fleas, for instance, we bring flour bugs inside our homes as well. Of course, we don’t do that on purpose, but it happens. Buying cheap flours, wheat products, grain starches and so on can lead to flour mite or flour weevil infestations. A couple of these bugs can lay many eggs, which will soon hatch, especially in warmer conditions. Considering that those types of foods are usually being stored for longer periods, the eggs have even bigger chances of surviving. The young pests hatched from those eggs might even have the chance to lay their own eggs while you realise what is happening.
If you have suspicions that your flour is contaminated with flour mites you have a couple of ways to check for them.
The first one is to take a pinch of the flour and roll it between your fingers. If it has a minty smell to it that is a good indicator that you have mites. Check for brown dust amongst the flour grains. The tiny white bodies of mites are extremely hard to spot, but their brown legs and the remains of dead mites could appear as brown dust.
Another way is to spread some flour on your kitchen countertop. Make sure you leave the top layer smooth. Let it sit there for half an hour or so. If the surface is not smooth, as you left it, you have flour weevils or mites.
The third method is to go through your cupboards with a piece of sticky tape. Stick it to the packaging of cereals, flour, grains and others. Examine the tape afterwards with a magnifying glass. If there were any flour mites on those packages they will be now trapped on the tape. You will be able to see them easily with the magnifying glass.
Generally, flour weevils are far easier to spot, so you will most likely use those methods to check for flour mites.
If it is so easy for pests to invade our stored foods and they are hard to spot, are they dangerous to us?
Flour weevils don’t bite nor sting and they are not poisonous. It is safe to say that they are not harmful. Even if you consume a couple with your cereal, nothing will happen. You most likely won’t even notice.
But are flour mites harmful? Mites on the other hand also don’t bite, sting nor are poisonous, but can spread the fungus. This is associated with mouldy taste or even visible mould. Moulds could make some people sick, especially when consumed. You will quickly realise if the food is mouldy by the looks of it or with your first taste, so you won’t finish that meal. However, for the people that are allergic to mites, consuming them can cause skin irritation, throat swelling and heavy breathing. In such cases, you should seek medical help. Fortunately, scenarios like that one are extremely rare.
There is no way to treat the pests with pesticide, considering that they live in your food source. Sadly, you can't just leave carnivorous plants in the cupboards neither. This leaves you with only one option. Throw away anything that came in contact with the contaminated food. This might cost you a couple of boxes of your favourite cereal, but it is a better option than letting the infestation spread to other cupboards.
After you have taken all of the contaminated foods to the outside bin it is time to thoroughly clean the cupboards. Use warm soapy water and make sure you get into the corners.
You can freeze the flour or wheat products right after you get them home. This will kill all present pests and prevent their eggs from hatching. This is a bit of hassle to go through only because of the assumption that there MIGHT be mites or weevils in those products, but it is a valid method.
To prevent such pests from roaming your pantry, keep your supplies in clean, clear containers that could be well sealed. The addition of a couple of bay leaves around your stored foods will act as a repellent. Put a couple of leaves in each cupboard, just as a safety measure. Mini dehumidifiers are also a great idea. Place them inside your storage areas, this will not only keep your stored products fresh, but it will make the habitat unpleasant for more pests. If you can keep those areas relatively cool, even better. Pests need humid, warm areas to flourish, so don’t make it easy for them.