Though many homeowners associate pest control with garden plants, protecting your lawn grass from pests is just as important a duty of responsible homeowners. There are many different types of insects that can be considered pests of lawn grass, flies being one of them. Luckily, there are many different treatments that you can apply to the lawn that are lethal to flies.
Fly Pests of Lawns
Since lethal insect treatments should always be targeted at specific fly species, it is necessary to first examine the species of fly that are most likely to attack your lawn grass. Species such as the Australian sod fly, the crane fly and the frit fly are commonly found infesting lawn grasses. Typically, damage is incurred when adult flies lay eggs in the soil underneath the grass and the larvae feed on grass roots as they develop, leading to diminished new growth and grass dieback.
Natural Lethal Methods
Natural methods, or those that do not involve the use of a synthetic insecticide but that still result in killing the fly pests, differ from species to species. Introducing natural predators of the fly and its larvae is often recommended; predators either kill the adult flies before they are able to lay eggs, or parasitise the fly larvae. Should the predators not occur naturally in your lawn, often you can purchase them and introduce them to the lawn environment.
The most effective lethal option for fly control on your lawn is often chemical pesticides. Systemic or preventive pesticides are applied when starting a new lawn from seed, or when the lawn is in a dormant state, and are intended to prevent the flies from laying eggs in the soil. Contact insecticides are used as "rescue treatments" to kill flies after an infestation is discovered. Either type of insecticide can be lethal when used properly, but the most important consideration to make when choosing an insecticide is to use one that is approved to kill the exact species that is infesting your lawn.
If you do plan to use a chemical pesticide treatment on your lawn, it is of critical importance to always use one that is safe for use on outdoor lawn grasses, and to follow the manufacturer's application instructions meticulously. Avoid using pesticides near garden plants, food plants, trees or any other plants that may have a toxic reaction to insecticide particulates that inadvertently drift onto the plants from the grass.