Latin: Tenebrio molitor
Mealworm beetles only lives a short time, but in the short time it can be a great inconvenience to humans. The larva, also known as mealworm, can cause great trouble to humans, which is the reason why this beetle is considered a pest.
Appearance
The fully grown mealworm beetle is relatively large; between 12 and 18 mm long. Color wise they can vary from dark brown to completely black. Mealworm beetles have a flat shape, and they have a long and wrinkled hind body.
Their front body is short and completely smooth in appearance. Like so many other beetles, they are shiny. From the top of the hind body, they have two wings, and it is possible for them to fly.
The larva of the mealworm beetle, commonly called the mealworm, is up to 30 mm long. It appears cubby compared to other larvae. It has a yellowish-brown color, almost a dark beige, and it has horizontal, dark strips down the body, which makes it resemble a worm. However, the surface of the mealworm is harder than that of a common earthworm, and it also has the glossy surface that its adult version has.
Biology and behavior
The mealworm beetle belongs to the family of shadow beetles (Tenebrionidae). Both adults and larvae are nocturnal. The adult beetles can fly and can be experienced in the middle of summer. The adult female beetle lays about 200 eggs during its 2–4-month adult life. The eggs are laid in starchy products, such as flour, grain, bread, and cereals.
It takes a long time for the mealworm to develop; the development from egg to larva and to adult beetles can vary between 280 and 630 days. The development variate so much because they are highly depende on the temperature and humidity of the environment as well as the nutrition of the larva. The ideal temperature for the mealworms is 26 degrees.
When the larva is fully developed, it will pupate. This stage lasts just two weeks, after which it is a fully grown mealworm beetle. You can of course find mealworms in grain and flour, but you can also observe them in sparrow nests, where they survive on wasted feed and they can easily hide in the nest.
Damage
Mealworms are harmful to humans, as they can infect one’s kitchen cabinets and food. Their presence in flour, grains, and bread can be extremely frightening for some people, perhaps because of the mealworm’s appearance.
It should be noted that some people use mealworms to feed aquarium fish and various animals in terrariums, so they are of some use to humans after all. Likewise, in recent times there has been a greater focus on the nutritional content of mealworms, and there are some people who eat mealworms regularly. However, the mealworm beetle may host the parasite Hymenolepis diminuta, and the mealworm or mealworm beetles should therefore not be eaten raw by humans.
Prevention and control
In private homes, it can be difficult to prevent the mealworm beetles and mealworms, this is mostly because they primarily are dealt with in the industry. By keeping the temperature low and the air environment healthy, you can typically prevent mealworm beetles and mealworms.
If you have problems with mealworm beetles returning to your kitchen cabinets, there is most likely a place nearby where the mealworm beetles can reproduce, lay eggs, and thrive. You should look for a hatchery and if you can’t find one in your home, it could be a sparrow nest causing the problem. By removing the given sparrow nests and making it harder for the birds to build nests in the tree, one can quickly get rid of the mealworms as well as the beetle. If the hatchery is in your home, you can treat the area with insect powder. Be sure to follow the instructions on the product carefully, and make sure that children and pets do not get close to the affected area. If you have found mealworms or beetles in your flour or bread, you should immediately discharge the infected goods.
"Pests in House and Home"
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"Food Pests"
"Husets dyreliv" (Insects Around the House - Only danish)
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