Seeds Pests and diseases
Sciarid gnats (Sciaridae) go through different stages of development. The fully grown animals lay around 200 to 250 transparent eggs about a millimeter deep in the grow medium and their larvae then hatch from the grow medium - mostly from soil-based substrates - and can then be found everywhere after a short time.
The adult insects are relatively harmless. The larvae, which systematically attack the roots of cannabis plants and thus limit their ability to absorb nutrients, cause the greatest damage. In addition, the damaged roots tend to rot. This leads to leaf yellowing, slowed growth and even dead hemp plants.
Like other insect species, fungus gnats are often difficult to find at first. If there is any suspicion, gently dig through the surface of the medium with your hand. There larvae are shiny, gray-white. They keep crawling out of the grow medium and back again. Adult specimens are easy to spot: they are buzzing around and appear quite confused.
The earlier you recognize fungus gnats, the less damage the hemp will be. Adhesive strips are a good prevention against sciarid gnats. One can significantly reduce the risk of their occurrence by not over-watering the cannabis. This is because Sciaridae like to settle on soaked culture media and rotting cannabis roots.
Sciarid gnats are one of the most common pests, especially in indoor weed growing. It is therefore not surprising that there is a large selection of biological and chemical products (Calypso should be emphasized here), all of which promise to get rid of them in next to no time. Of course you should try an organic product first.