Hover flies, also known as flower flies or syrphid flies, are common garden insects that often resemble bees or wasps due to their yellow and black markings. These insects are completely harmless and incapable of stinging. They are beneficial insects that serve as pollinators and natural pest controllers, and their presence on a patio usually means they are seeking out specific resources like moisture or a food source. Since they are helpful to the environment, the most effective approach to reducing their presence is through safe, non-toxic methods that modify the immediate environment rather than eliminating them entirely.
Identifying What Attracts Hover Flies to Patio Spaces
The presence of hover flies on a patio is directly linked to the availability of three primary attractants: food, moisture, and specific plant matter. As adults, these flies feed on nectar and pollen, but they are also highly attracted to sweet spills left behind from beverages or food residues. Uncovered garbage bins or pet food left outside can also emit odors that draw them to the area, as they seek out accessible sugar or decaying organic material.
Moisture is another significant factor, particularly during dry periods or hot weather, as all insects require water for survival. Standing water in plant saucers, bird baths, leaky hoses, or damp areas beneath outdoor furniture can become a regular watering spot for the flies. Eliminating these small pools of water can quickly make the patio less hospitable for them.
A third attractant is the presence of aphid infestations on nearby ornamental or edible plants. Female hover flies are instinctively drawn to aphid colonies, where they lay their eggs so the newly hatched larvae have an immediate food source. The larvae are voracious predators of soft-bodied pests like aphids. If you notice hover flies around specific plants, it strongly suggests an underlying pest problem is the root cause.
Quick and Safe Removal Methods
One of the simplest and most effective strategies is using an electric fan to create a strong air current across the seating area. Hover flies are named for their unique ability to hover, but they find it difficult to maintain their flight pattern and position in moving air. The forced breeze causes them to move away from the area.
A mild, non-toxic spray solution can quickly discourage flies from landing on surfaces. Mixing a few drops of liquid dish soap with water creates a solution that can be applied to surfaces where flies are landing frequently. The soap disrupts the fly’s surface tension when they land, making the area unattractive and causing them to leave. This method should be used on surfaces and not directly on the flies themselves.
Immediate cleanup of all sugary or fermenting spills provides quick removal and short-term deterrence. Hosing down or thoroughly wiping all surfaces immediately after a meal or beverage spill eliminates the strong scent that initially attracts them. For stronger surface cleaning, a diluted white vinegar and water mixture can be sprayed and wiped on tables and floors. This solution cleans and leaves behind a scent that many insects find repellant.
Strategies for Long-Term Deterrence
Long-term deterrence relies on environmental modifications that make the patio consistently unattractive to hover flies. Maintaining a strict cleaning routine is necessary, ensuring that all food scraps, drink spills, and organic debris are removed immediately and thoroughly. All outdoor waste containers, including garbage and recycling bins, should have tight-fitting lids to seal in odors that draw flies.
Eliminating all sources of standing water prevents the flies from accessing a reliable hydration source. This involves routinely emptying and drying out water from decorative items, children’s toys, and the saucers beneath potted plants. Even small amounts of water that accumulate in depressions on the patio surface should be swept away immediately.
Addressing Aphid Infestations
Addressing aphid infestations on nearby plants is a necessary preventative step, as the presence of these pests serves as a beacon for egg-laying females. If aphid-infested plants cannot be relocated away from the patio, applying insecticidal soap or neem oil can reduce the pest population. This removes the primary incentive for hover flies to visit the area.
Using Natural Deterrents
Strategically placing certain herbs on or near the patio can provide a natural deterrent. Planting strong-smelling herbs like mint or basil in containers releases aromatic compounds that hover flies tend to avoid, acting as a passive preventative measure.