What can be done against sciarid gnats?

The most important points in brief

• Nobody wants pests in the house and garden. Sciarid gnats don't quite belong in this category, but they are always annoying.
• On the other hand, the small insects can be dangerous for our potted plants.
• They feed on the roots of our indoor plants and spread rapidly through rapid reproduction.
• However, there are a number of ways you can get rid of the annoyances.

Have you ever noticed that when you water the houseplants, a small swarm of tiny insects rise up? These are fungus gnats, the larvae of which are often found in newly purchased potting soil. After hatching, they buzz around the apartment and eventually settle down on the plants again. They don't go for food, they don't bite us either - but fungus gnats are annoying anyway.

Sciarid gnats don't bite

Although they do not consume human blood, they are mosquitos and only live a few days. According to this, fungus gnats would hardly be a nuisance if they did not reproduce in such high numbers. In the few days of their earthly existence, the females lay about 300 eggs.

The preferred place to lay the eggs is potting soil, preferably moist. There the larvae eat the roots of the plants, which can be particularly dangerous for young shoots and flowers. Because it is not uncommon for pathogens to nestle in the plants that penetrate through the eroded areas. In a broader sense, this genus is actually about pests - and you want to get rid of them as soon as possible. But what is the best way to do that? Conventional mosquito remedies do not necessarily get you very far. But there are a few tricks.

Against fungus gnats: heat potting soil in the oven and sterilize

In order to prevent the larvae of the sciarid gnats from hatching, you can easily sterilize the newly purchased potting soil. Before you put them in a saucepan for use, distribute the desired amount on a baking sheet and put it in the oven at 200 degrees for a little less than half an hour. The larvae have no chance against this.

Or you can tackle the insects with other pests - for example with the nematode genus Steinernema feltiae. Dissolve the white powder in water and add it to the pouring water, stirring well. The nematodes destroy the sciarid fly larvae within a maximum of three weeks.

Yellow boards, quartz or matches help against fungus gnats

You can also get rid of the mosquitoes with standard yellow boards. Simply place the boards, which are adhesive on both sides, close to the plants affected by fungus gnats. The yellow color attracts the mosquitoes and they simply stick to the boards. Bird sand, gravel or quartz sand, spread about three or four millimeters thick on the soil of the infested plants, are also suitable remedies against fungus gnats.

Before you buy quartz sand or bird sand, you can try sulfur first. What sounds awkward at first could hardly be easier if you have matches at home. Simply insert the matches into the soil of the infested plants with the sulfur heads and water them. With the water, the sulfur is distributed in the soil - and kills the larvae.