Like most of the pests of indoor garden humid, warm and damp conditions are optimum to invade. Fungus gnats are one of the most common houseplant pests. Both larval and adult stage of Fungus gnats can damage houseplants. Small hatched larvae have a gleaming clogged mouth and prolonged greyish to whitish body. This stage is most plenteous in clammy soil. Larvae inhabiting in pots/soil/lower portion feast upon root hairs and other natural materials. Root hair damage makes a plant weak and yellowish. They enhance the chances of occurrence of damping of fungi that attack roots. In next phase, larvae turn into flies comparable to mosquitoes/fruit fly possessing black to grayish shade of their gentle elongated (a few centimetres) body with one clear set of wings. They have life cycle of about 4 weeks and lay a large number of eggs.
''How to differentiate Fungus gnats and fruit fly?'' Body colour is the most noticeable feature to differentiate. fungus gnat is darker one.
''How to control fungus gnats?'' Regularly inspect your growing area from the time of plantation usually (pre spring or end of winters) till the harvesting. Adult fungus gnats invade in pots and will increment in number step by step by laying many eggs. So its recommended to control them as soon as possible by using suitable sprays.
These delicate insects do not seem like causing a serious damage to your houseplants but they harshly effect growth and health making them prone to other fungal diseases. Healthy harvest offers safe and organic fungicides/miticides/insecticides/pesticides that are effective for every stage of pest's life cycle. Selected items are best for organic gardening and for spraying on all sort of edible or ornamental houseplants.