Midges are small, flying insects that can turn outdoor spaces into uncomfortable environments, frequently appearing in large swarms around dawn and dusk. These tiny pests, which include both non-biting midges and biting varieties like “no-see-ums,” are often mistakenly identified as gnats or small mosquitoes. Controlling an outdoor midge problem requires a focused strategy that targets their reproductive cycle and reduces the adult population. The most effective approach involves a combination of removing the source of the infestation, actively reducing adult numbers, and employing personal protection tactics.
Eliminating Midge Breeding Grounds
The most effective, long-term strategy for midge control is disrupting their life cycle by removing the places they reproduce. Midges require a moist environment, typically stagnant water or wet organic matter, to lay eggs and for the larvae to develop. This reproductive stage can be completed in as little as two to three weeks, meaning new adults emerge rapidly if the source is not addressed.
Standing water is a primary breeding site, whether it is in a discarded tire, a birdbath, or a poorly draining section of the lawn. Correcting landscape drainage issues prevents water from pooling after rain, and ensuring gutters are clear stops water from stagnating near the home’s foundation. Larvae also thrive in nutrient-rich muck, often found in stormwater systems, ponds, and wet soil with decaying leaf litter or excessive thatch.
Addressing this organic matter through improved aeration and removing damp debris, such as wet mulch or compost piles, is a necessary step. For water bodies that cannot be drained, a biological larvicide containing Bacillus thuringiensis israelensis (Bti) can be applied. Bti is a naturally occurring bacterium that specifically targets and kills midge and mosquito larvae without harming fish, pets, or other wildlife. By eliminating the larval habitat, the number of emerging adult midges is significantly curtailed.
Immediate Reduction Methods for Adult Midges
When a midge problem is already established, immediate measures are needed to reduce the existing adult population while long-term source control takes effect. Insecticides containing synthetic pyrethroids, such as lambda-cyhalothrin or permethrin, are commonly used for barrier treatments. These products are applied to surfaces like exterior walls, shrubbery, and tree trunks where midges rest, killing them on contact and providing residual control for up to 90 days.
The application of a residual barrier is often supplemented with an Insect Growth Regulator (IGR) to stop the development of any remaining immature pests. For large swarms or for rapid knockdown before an outdoor event, fogging with a ULV cold aerosol generator can be employed. This method disperses a fine mist of insecticide that contacts and kills flying adult midges, offering immediate but temporary relief.
Alternatively, non-chemical methods like light traps can be used to capture adult midges, as many species are attracted to light sources. While commercial traps can help monitor and reduce localized populations, they are generally not sufficient for controlling a massive infestation alone. Traps that use carbon dioxide as an attractant can be more effective at drawing in biting midges, but these methods are best used in conjunction with source elimination.
Personal and Environmental Repellent Tactics
Tactics focused on making the immediate outdoor environment less appealing provide a practical layer of protection for individuals. A simple, yet highly effective, environmental deterrent is the use of outdoor fans to increase air movement on patios and decks. Midges are weak flyers and cannot easily navigate in strong breezes, causing them to be dispersed from the area.
Barrier methods, such as installing fine mesh screens around porches or gazebos, physically prevent midges from accessing a dining or relaxation area. Personal protection is further enhanced by wearing light-colored clothing, as midges are often more attracted to darker colors. Applying a topical insect repellent containing active ingredients like DEET or Picaridin to exposed skin provides a direct line of defense when in infested areas.
Natural oils offer another option, with lemon eucalyptus, citronella, peppermint, and geranium frequently cited for their repellent properties. These oils contain compounds that midges find unpleasant, and they can be used in outdoor diffusers, candles, or applied to clothing. While these natural deterrents create a localized protective barrier, their effectiveness can be short-lived and generally does not match the duration of synthetic repellents.