The presence of mayflies in your home or community is actually not a bad thing. In fact, their presence indicates a healthy aquatic ecosystem, since they are completely aquatic in their nymph stage and cannot survive in polluted water sources. However, they become a nuisance during their mating periods, which can be several times during the summer. Mayflies are not harmful to plants, people, or pets. However, when they swarm in huge numbers, patios, sidewalks, and roads become slippery. The large swarms also make it extremely difficult to work in gardens and entertain guests outdoors.
Chemical insecticides are of no use against mayflies, but you can minimize or discourage their presence with other methods. The first thing to do is to make sure your home is uninviting to them.
Mayflies are attracted to lights
At nights, mayflies are attracted to lights, especially white light. Therefore, the easiest way to discourage mayfly swarms is to exchange white light bulbs for yellow ones on exterior lights. Additionally, to limit the amount of mayflies that will be attracted to interior lights, draw the shades at nights. Like a lot of other insects, mayflies don?t like the scent of garlic. An excellent home remedy that repels mayflies is a brew of garlic tea. First, you will need some crushed garlic, then add hot water and let the brew steep for a few hours. The solution will be more effective if you use plenty of garlic, the more potent the solution the better. Use a spray bottle to apply the solution to the exterior of your home. Alternatively, you can spread dry minced garlic around the perimeter of your yard.
Clean up possible habitats
Clearly, mayflies need water to survive for the first two years of their lives as nymphs. So start with a thorough clean up if you have standing water, water features or a pond in your yard. Slow moving water that contains algae and other organic matter that the nymphs can feed on provides the perfect incubation areas for them. Use floating water plants such as hardy water lilies that will help remove nutrients from the water and slow the growth of algae. To supplement, remove the accumulation of fallen plant waste, sediments and other organic matter from your water features regularly. Many pond fish also feed on the nymphs and helps to control the population of mayflies.
What you can do
Mayflies will only be around for a few days during their mating season in June and July to cause trouble. They mate in flight but, they will land on everything from walls to outdoor furniture. They are very delicate so you can easily sweep them away with a broom, or spray them with a hose ? this will not only get rid of them but clean up the mess as well.
You can shut them out. Mayflies particularly love the open air, but they sometimes become trapped within a structure. Keep doors closed and make sure that the screens on your windows fit tightly and have no gaps or holes in them. Temporary screen also works well for outdoor areas such as patios. Mayflies pose no threat to your plants so there is no need to cover them during a swarm, and the dead flies add valuable nutrients to the soil.