I have a problem with annoying flying gnat-type insects on my indoor plants. I have tried several things, some of which have been temporarily helpful, but the bugs are back in a few days. Is there a way to get rid of them forever?
The gnats that you see flying around your house plants are the adult form of the fungus gnat. Each adult lives for eight to 10 days and lays about 300 eggs in the soil of the plants. The eggs hatch in about four to six days and become larvae that feed on fungi and organic matter in the soil. They also feed to a limited extent on plant roots. After 12 to 16 days the larvae change into pupae. The pupae mature into adults which emerge from the soil in four to six days and the life cycle starts all over again.
There are several methods for controlling the adults and the larvae. However most of them have no effect on the eggs or pupae. That is why your methods have only lasted for a few days. You need to repeat your treatment every five days to kill the newly developing larvae and adults.
Fungus gnats are attracted to moist, water-logged soil. You need to change your watering practices to avoid getting them again once you have gotten rid of them. It is common for people to water all of their house plants at the same time, either on a schedule or when the driest one becomes dry. We get away with doing this because most potting soils are well drained and there is still adequate oxygen for the roots even when they are over watered. Plants should be watered individually only when the top of the soil becomes dry.
