Bug Blog

How Do Avoid Indoor Fungus Gnat Infestations, And How These Annoying Winged Pests Are Controlled Through Integrated Pest Management Strategies

Gnats are those tiny airborne bugs that are often seen near bodies of water, congregating on filth, and darting into people’s eyes, nose and mouth. Several species of insects in the Diptera order are commonly known as gnats, some of which bite humans, while others are merely an annoyance due to their thick swarms. Luckily, most gnats are not associated with the spread of disease, but the gnat species that are attracted to lacrimal secretions, or “tears,” have been known to cause conjunctivitis (pink eye) after making contact with mucous membranes on the corner of eyes. The gnat pests commonly known as fungus gnats do not bite or spread disease to humans, but they often become numerous within homes where they damage houseplants and pose a tremendous nuisance to residents.

The group of airborne insects referred to as “fungus gnats” is comprised of many species that proliferate within wet soil, fungi and rotting vegetable matter. Most indoor fungus gnat infestations see the pests emerge from wet topsoil in lawns and houseplants where massive numbers of larvae develop. In homes infested with large numbers of winged adults, fungus gnat larvae are surely abundant in nearby topsoil where they consume significant amounts of water and feed on decaying plant matter, seedlings and roots, causing damage and stunted growth to cultivated indoor and outdoor plants. In addition to feeding on plants, fungus gnat larvae spread disease from infected plants to healthy plants, resulting in eventual plant death.

Since fungus gnat larvae thrive in wet soil, these pests are particularly problematic in residential areas of Arizona where many lawns are irrigated. This is why it is important for residents to avoid overwatering indoor and outdoor plants. The top surface of soil should always dry before being watered again, as this will kill existing larvae and wipe out the next generation. Plants and potted soil should be inspected before being brought indoors, and placing sticky traps around plants will help to reduce existing adults. In some cases, professional soil treatments are necessary to eliminate fungus gnat infestations within homes.

Have you ever struggled to control fungus gnats in your home?