• Home  >  
  • Pests


The mealworm (tenebrio molitor) is an insect that belongs to the order of beetles. The adult has a robust and shiny shell of dark brown/black color. It generally measures between 14 and 18 mm long. The larva, on the other hand, is brown-yellow in color and grows in flour and other foodstuffs.
Mealworms are used as bait for fishermen as well as for animal feed. It is one of the most used species for reproduction in insect farming, especially for live food. They serve as food for many reptiles, amphibians and birds. They are also used for entomophagy, the consumption of insects by humans.
The mealworm is the largest insect found in whole grains and grain products. Mealworms are considered to be a relatively minor problem in commercial and residential areas. However, they are a significant economic threat in the poultry sector, for several reasons.

They are commonly found in bakeries, warehouses and places where food is stored. They are sometimes also found in homes, in dark and damp spaces.

Development and Behaviours

Mealworms go through a complete metamorphosis, so they go through 4 stages: egg, larva, nymph and beetle. The duration of their life cycle is very variable (between 4 months and 2 years) and depends mainly on temperature and food availability.

In nature, mealworms usually mate in early summer since the warm temperatures allow the eggs to hatch. A week after copulation, the female normally lays between 400 and 500 eggs and these hatch one or two weeks after depending on the temperature. The larval stage lasts between 5 to 7 weeks in a heated environment. However, without the proper weather conditions, the larval stage can last several months and even up to a year.

During this period, their color changes to yellow and their growth accelerates. Mealworms can molt 10 to 16 times during their development. Once they reach a certain size (between 25 and 30 mm long), they start to pupate. Two weeks later, the pupa turns into a beetle. If the conditions are good (humidity, temperature, food, etc.), the beetle can live for about three months.

Risks related to a mealworm infestation


Digging tunnels in the insulation of agricultural buildings, mealworms can reduce insulation levels by 30%. As a result, it can increase, by up to 67%, the energy costs necessary to maintaining the temperature in chicken coops.


Mealworms are recognized as a parasite that can be a carrier of up to 60 diseases that can contaminate either poultry or humans, such as avian flu, salmonella and E. coli. The period during which this parasite is contagious is sometimes long enough to infest the entire poultry yard! In addition, the infected chicks can also contaminate others, perpetuating a problem that becomes costly and difficult to counteract for producers. A single infected mealworm is sufficient to infect a bird.


Mealworms are often found around food conveyor lines and feeders and the poultry sometimes eat them before their feed. The birds fill their stomachs with the insects, leaving no room for feed. Since mealworms take longer to digest than feed, the birds take longer to reach their optimal weight. As a result, the number of production days increases or the birds at the end of their growth period are smaller than they should be. In both cases, it causes evident losses for the producer.


People who are constantly exposed to high mealworm populations can develop allergies, asthma and conjunctivitis.

Contact us immediately to obtain effective long-term control solutions for mealworms.


Here are some techniques to prevent a mealworm infestation:

  • Keep your warehouse, silo, storage space or pantry clean. Make sure to empty, clean, disinfect and ventilate these spaces regularly.?
  • Avoid storing your food in bags, since mealworms could easily break them and eat their contents. We recommend the use of containers that can be hermetically sealed (glass or solid plastic).?
  • When you go to the grocery store, check your purchases. These insects can arrive in your pantry directly from the supermarket.?
  • Keep food that you won't eat right away in the freezer.?
  • Make sure to empty the bins frequently.?
  • Clean and ventilate regularly.?


If you have a mealworm infestation, it is recommended that you hire a professional exterminator to safely, quickly and effectively get rid of these pests.

The mealworm exterminator can use various techniques to exterminate these insects such as eradication by heat or chemical treatment as well as elimination by pneumatic conveyor.
At Vextermination, we are experts in eco-friendly pest management. Our technicians all have a certificate from the Ministère du Développement durable de l’Environnement et de la Lutte contre les changements climatiques. We have an emergency service available 24/7 to meet all of your pest management needs. Contact us!

Made by Triomphe marketing et communication