The flour beetle nestles in starchy, dry foods such as flour and other grain products. The pest is comfortable in the warm and dark surroundings, and it also finds food in abundance here. Dispose of supplies infested with flour beetles immediately, and you should also search your premises for other hidden animals. To do this, you can use pheromone traps, which attract adult beetles ready to mate.
The nocturnal flour beetle reproduces sexually, with male and female animals hardly differing from one another. Mating takes place at the beginning of summer. The female then lays between 200 and 300 eggs - preferably in warm and dark places such as pantries with openly stored flour and other grain products. The tiny, white and sticky eggs are invisible to the naked eye in the flour or oatmeal. However, if the flour cakes strangely or if the oat flakes stick together, you can assume an infestation.
Tip: The nocturnal flour beetles are attracted by light. So close the windows as soon as you turn on the lights or install mosquito nets in front of the windows and patio or terrace nets. Balcony doors.
In private households, the most important control method is to carefully search all supplies for signs of infestation and to dispose of contaminated food immediately. A clear indication of in flour, cereal flakes, etc. ä. laid eggs is that they suddenly bake together and sometimes even threads can be seen. The larvae can often be discovered when they are sieved out.
In addition, in order to actually catch all flour beetles and thus prevent a renewed infestation immediately, you should not just dispose of their supplies. The animals also like to hide in cracks and joints, small caves and behind cupboards. So vacuum off all the regions in question - all cracks, etc. - and move the cabinets to clean them from the rear as well. Don't forget to check the cupboards too!
Tip: Repeat this process every few days for four to six weeks as you won't catch all of the bugs and their offspring at once.
If you are on the safe side and are more likely to avoid a renewed infestation from the outset, you should also try these measures:
Tip: Pheromone traps are not suitable for fighting meal beetles, as they are only used to catch the males. However, such a trap can help you to realistically assess the extent of an infestation. In addition, the captured males are no longer able to fertilize existing females, so that the population is limited according to the catch quota.
The latter is an extract from the flowers of various types of chrysanthemums, which has been used successfully for pest control for centuries. The preparations mentioned are particularly useful for treating hard-to-reach areas.
Tip: Never use insecticides that are not specifically approved for indoor use - especially if you plan to use them in the kitchen. The poison not only kills the meal beetles, it also penetrates your food.
Tip: You should also check your kitchen cupboards regularly to see whether there is a forgotten bag of flour in the far corner.
Characteristics
Type: Flour beetle
Scientific name: Tenebrio molitor
Family: Black beetle (Tenebrionidae)
Common names: Mealworm
Appearance of the adult animal: elongated, flat, black-colored body; Underside, limbs and antennae reddish brown; Grooved wing surface
Length of the adult animal: 10 to 18 millimeters
Appearance of the larva: yellowish brown, with noticeable darker rings, between 20 and 25 millimeters long
Occurrence: worldwide; prefers dark and warm places: pantries and other places with flour and grain products, also in the wild (pigeon and other bird nests, dead wood)
Way of life: nocturnal
Food: mainly starchy foods, often flour and other grain products
Development: complete metamorphosis
Harmful effect: Eating damage to food, carrier of pathogens (bacteria, but also dwarf tapeworm)
Combat: Immediate removal of contaminated supplies in private households
Use: Larvae as food worms for pets (birds, reptiles, amphibians or fish), approved as food for humans in Switzerland since May 2017
Reproduction
The nocturnal flour beetle reproduces sexually, with male and female animals hardly differing from one another. Mating takes place at the beginning of summer. The female then lays between 200 and 300 eggs - preferably in warm and dark places such as pantries with openly stored flour and other grain products. The tiny, white and sticky eggs are invisible to the naked eye in the flour or oatmeal. However, if the flour cakes strangely or if the oat flakes stick together, you can assume an infestation. Growth and development
The mealworm larvae that hatch from the tiny eggs are also known as mealworms, although from a scientific point of view they are of course not worms. Immediately after hatching, they are only two millimeters long, but grow very quickly to an average length of 20 to 25 millimeters. In doing so, they shed their skin several times and, over time, take on a yellowish-brown color with darker rings. The animals feed on the food around them and pupate in it. Freshly hatched adult beetles are initially very light in color, but darken within a few hours. The entire life cycle takes place within three to four months, after which the beetle dies. Several generations of the meal beetle can develop each year.Harmful effect
A flour beetle infestation is often only noticed when it is well advanced. First and foremost, the harmful effect in private households is that all infected Food must be disposed of immediately - and not in the household garbage, but directly in the Garbage can. Otherwise, the larvae will simply continue to develop in household waste and pupate there, with the result that renewed infestation cannot be stopped. The meal beetle can also transmit disease if you eat contaminated food. The pest is considered to be the vector of the dwarf tapeworm (Hymenolepis nana), which can grow up to six centimeters Can grow long and primarily found in the intestines of children and people with weak immune systems nests.How do the mealworms get into the meal?
There are several ways the flour beetle gets into flour (or other supplies). In what is probably the most common variant of transmission, you bring the pest into your home through foods that have already been contaminated with eggs or larvae. An infestation already took place in the mill or during the manufacturing process, which the manufacturer did not notice. The meal beetles then multiply quickly in private households and also attack other supplies. However, this is not the only way to bring flour beetles into your home. You get u. a. also like this:- from pigeon or bird nests under the gutter
- from the garden (accumulated dead wood, mulch material, compost)
- escaped animals from breeding, e.g. for terrarium animals
Tip: The nocturnal flour beetles are attracted by light. So close the windows as soon as you turn on the lights or install mosquito nets in front of the windows and patio or terrace nets. Balcony doors.
Combat
In private households, the most important control method is to carefully search all supplies for signs of infestation and to dispose of contaminated food immediately. A clear indication of in flour, cereal flakes, etc. ä. laid eggs is that they suddenly bake together and sometimes even threads can be seen. The larvae can often be discovered when they are sieved out.In addition, in order to actually catch all flour beetles and thus prevent a renewed infestation immediately, you should not just dispose of their supplies. The animals also like to hide in cracks and joints, small caves and behind cupboards. So vacuum off all the regions in question - all cracks, etc. - and move the cabinets to clean them from the rear as well. Don't forget to check the cupboards too!
Tip: Repeat this process every few days for four to six weeks as you won't catch all of the bugs and their offspring at once.
If you are on the safe side and are more likely to avoid a renewed infestation from the outset, you should also try these measures:
1. Setting up pheromone traps
Pheromones are sexual attractants that are only perceived by adult animals. The classic pheromone traps contain an attractant for male meal beetles and serve less for targeted control than for the detection of pest infestation. Set up several of these traps and wait a few days: Males ready to mate will stick to the adhesive surfaces so that they can dispose of them together with the traps. If it is only a question of individual animals, they may come from the garden and there is (yet!) No infestation. However, if the finds pile up, the best thing to do is to find the source and take appropriate action.Tip: Pheromone traps are not suitable for fighting meal beetles, as they are only used to catch the males. However, such a trap can help you to realistically assess the extent of an infestation. In addition, the captured males are no longer able to fertilize existing females, so that the population is limited according to the catch quota.
2. Setting up UV light traps
So-called UV light traps are also used to catch adult meal beetles. In this case, however, both males and females literally fall for the trap. Light traps are designed in such a way that they attract the nocturnal beetles and these ultimately stick to the integrated adhesive surface. The adhesive surface together with the trapped beetles can be disposed of, the lamp itself can be used on average for up to 9,000 hours. Again, you should not use the trap as the sole control measure, because it only attracts the adult animals. The hidden larvae and pupae remain hidden and can develop undisturbed.3. Application of non-toxic insecticides
In agriculture as well as in industry (for example in grain mills or bakeries), packaged grain or Grain products for control or fumigated with nitrogen, carbon dioxide or hydrogen phosphide to prevent mealworms. If infestation is proven, thermal processes are also used in such systems all stages of development of the meal beetle are killed at temperatures of 60 ° C and more. Of course, such methods cannot be implemented in private households. But even here you can use non-toxic contact insecticides, for example based on silica, neem or tea tree oil or pyrethrum. The latter is an extract from the flowers of various types of chrysanthemums, which has been used successfully for pest control for centuries. The preparations mentioned are particularly useful for treating hard-to-reach areas.Tip: Never use insecticides that are not specifically approved for indoor use - especially if you plan to use them in the kitchen. The poison not only kills the meal beetles, it also penetrates your food.
4. Thermal methods
So that flour beetles cannot develop from the larvae and pupae found in the stores, should Put the food in question in the freezer compartment of your refrigerator for a while before disposing of it pack. Frost kills both adult and juvenile animals just as reliably as temperatures above 60 ° C.prevention
A meal beetle infestation can be prevented from the outset through targeted preventive measures. The following tips are useful for this:- dry supplies such as flour, oat flakes, muesli etc. do not store long
- instead use it quickly
- and buy fresh more often
- Close the storage container tightly
- Never store supplies openly (e.g. B. Leave flour in bags)
- Thoroughly inspect newly purchased supplies before placing them
- from early summer set up pheromone traps for control purposes
- Quickly remove pigeon and other bird nests on and around the house
- Regularly check stocks that have been stored for a longer period of time
Tip: You should also check your kitchen cupboards regularly to see whether there is a forgotten bag of flour in the far corner.
