In the household, parasitic wasps are usually used against food moths and clothes moths. However, the real pest in both moth species is not the moths, but their larvae, as they cause the most damage. The clothes moth nests mainly in the closet, in upholstered furniture and carpets, where it finally lays its eggs. The food moth, on the other hand, feels particularly at home in the pantry or in the kitchen cupboard. Food moths are often introduced when buying food. In this guide you will learn how to use parasitic wasps against moths.
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Differentiation between the two species of moth
Food moths and clothes moths look very similar on the outside. For example, if they are sitting against a wall in the apartment, you cannot immediately identify them. You can tell them apart by their flight behavior. While the food moth flies rather calmly and in a straight line, the clothes moth shows a tumbling, fluttering flight.
Advantages of control with parasitic wasps
Ichneumon wasps are the natural enemies of moths. They are very small, about 0.4 mm in size, and can hardly be seen with the naked eye. They cannot sting, crawl or fly around. The eggs of the parasitic wasps are attached to small cards that can be ordered from the beneficial insects mail order service and placed on the spot at home, for example in the wardrobe or kitchen cupboard.
The parasitic wasps are only interested in the eggs and larvae of the moths. They also cannot get into food packaging. They are completely harmless to humans. If there are no more eggs and larvae, the parasitic wasps disappear on their own.
- An infestation by the clothes moth is often only recognized relatively late.
- First you notice small holes in the clothes.
- Sometimes you can also see isolated moths sitting on the walls.
- However, it can also be the food moth.
- The clothes moth prefers high-quality woolen fabrics in particular.
- Textiles made of synthetics or cotton are generally avoided.
- The parasitic wasp Trichogramma evanescens is used to combat it.
- This is very small at 0.3 to 0.4 mm and cannot fly.
- She tracks down moth eggs with her sense of smell.
- The parasitic wasp parasitizes the eggs of the clothes moth with its own eggs.
- Then those of the clothes moth die off.
Optimum conditions for the parasitic wasp
This parasitic wasp finds optimal living conditions at room temperatures of around 22 degrees and a relative humidity of between 65 and 70 percent. These conditions are usually the same as those found in chests and closets.
Control of the clothes moth
First you should check whether a moth infestation is actually present. This can be determined very well with special pheromone traps from specialist shops. If you have laid them out and moths can be seen on them within a few days, there is an infestation.
Since parasitic wasps cannot get everywhere, every corner should be examined and thoroughly cleaned beforehand, because crevices, cracks, folds and hidden spots are popular retreats for moths. In addition, moths are very sensitive to heat, which is why it can be helpful to use a hair dryer in such areas.
Ichneumon wasps are living animals whose eggs are attached to small cards and thus sent by post. After receiving the parasitic wasps, the cards should be laid out as soon as possible. If this is not possible, they can be stored for a maximum of 1-2 days at 8-12 degrees, for example in the refrigerator.
All clothing or textiles in which you have found feeding holes should be placed in a closet and the cards placed directly between the items. Within a few days, the parasitic wasps crawl out of the slits on the side of the cards and immediately start looking for moth eggs. Textiles that can no longer be saved should be disposed of with household waste in well-sealed plastic bags.
At intervals of three weeks, parasitic wasps are then delivered in six partial deliveries, which should then also be laid out as soon as they are received. The old cards can then be removed.
The subsequent deliveries of new parasitic wasps are important in order to catch all moths. After the last delivery, the moth infestation should usually be over. By laying out pheromone traps, one can check whether moths are still present or not.
Prevent clothes moths
- You can prevent an infestation with the clothes moth.
- For example, worn clothing should be washed regularly or at least aired out well.
- Wardrobes should always be kept closed.
- From time to time also the cracks in the closet itself, clean with the vacuum cleaner!
- Valuable items of clothing can be stored in garment bags for protection.
- These should be made of synthetics or cotton if possible.
- Clothing should also be kept as cool and dry as possible.
- Fly nets on the windows, especially in summer, can protect against moths.
Even with the food moth, it is not the moths themselves that cause the damage, but their larvae or the voracious caterpillars. The first signs of an infestation are usually small holes in food packaging. However, since the caterpillars are still very small after hatching, the holes they cause are correspondingly tiny, so that you sometimes don’t even notice them.
Clumped flour or muesli is usually a clear indication of an infestation. Web-like structures in the food are then usually a sign of an already advanced infestation by the food moth. The food moth also spreads very quickly, so that action should be taken as soon as possible.
Control of the food moth
First you should try to find the actual focus of infestation, which does not necessarily have to be in the same room. This can be in the pantry as well as in the basement or pet cage. If you have found it and eliminated it, it can make the fight much easier and faster.
If it is not possible to find the source of the infestation, all infested food and its packaging should be disposed of immediately. Packages that appear to be intact and sealed, as well as all endangered food, should also be disposed of, even if it hurts, because the food moth or its caterpillars can already populate these as they can get through the smallest openings. It is better to throw away a little more than too little. Otherwise it can happen that you cannot get rid of these stubborn pests and they spread throughout the apartment.
Use of parasitic wasps
As with the clothes moth, the parasitic wasp Trichogramma evanescens is also used to combat the food moth. Here, too, she lays her eggs in those of the moths, from which no moths but new parasitic wasps hatch. First you order the parasitic wasps. These usually arrive within a few days. In the meantime, after disposing of the groceries, you should wash the affected cupboards thoroughly with vinegar water.
The cards with the parasitic wasps, usually three of them, are automatically sent over a period of nine weeks by the respective beneficial insect dispatcher, three times each, at intervals of three weeks. A period of several weeks is necessary because this time corresponds to the development cycle of the food moth from egg to moth and this cycle must be interrupted.
Depending on the provider, each of these cards is equipped with around 3,000 parasitic wasp eggs. While six applications are required for the clothes moth, three are sufficient for the food moth in most cases, depending on the degree of infestation.
After receiving the cards with the parasitic wasps, these should also be laid out at the site of their activity as quickly as possible. One of these cards is enough for a closed cupboard compartment or a shelf about one meter wide. When the parasitic wasp has done its job and all moths have been destroyed, it either disappears through the open window or dies. She disappears just as quietly and unobtrusively as she did her work.
Food moth prevention
The food moth can also be prevented with various measures. First, you should avoid leaving food out in the open so the moths can’t lay their eggs in there. The food moth is very often brought in when you buy food.
It is therefore advisable to open food in bags, such as flour, pasta, muesli, rice or cocoa, immediately after purchase, check for a possible infestation and then transfer them to sealable containers, such as sealable jars, and so in to put the pantry.
In addition, you should only ever buy as much food as you can consume in a relatively short time, keeping large stocks is not recommended. This applies not only to food, but also to animal feed, which can also be used to bring this pest into your home.
Supplementary use of pheromone traps
Pheromone traps are not usually primarily used against clothes moths or food moths. However, you can prove a possible infestation and also significantly increase the effect of the parasitic wasps. It is best to use the pheromone traps together with the parasitic wasps.
These traps are sticky traps that contain a specific attractant for female moths. The male moths are supposed to be attracted with this attractant. These then stick to these cards and die. The traps, like the parasitic wasps, must remain in place for several weeks, but at least for six weeks.
For the duration in which the traps are laid out, it is important to ensure that all windows in the room in question are closed. Otherwise, these pheromone traps could also attract male moths from outside, adding to the problem.
Both the clothes moth and the food moth can be very stubborn. Many get goosebumps just thinking about it. However, there are a number of things you can do to prevent these two nuisances. And if none of that helps and the moths have been brought in, the parasitic wasp is a very good and effective help. And with the support of pheromone traps and other beneficials, the whole thing is amplified. Despite everything, you should act as quickly as possible in the event of an infestation and then check again and again to prevent a new pest population.