Fruit flies are one of the less pleasant parts of summer. By now, a lot of you are probably noticing an influx of the little guys. While common fruit flies, also known as "vinegar flies", are annoying, they don't pose a major threat to humans. There are some invasive types of fruit flies, which damage fruit crops. However, non-invasive species of fruit flies are more of a nuisance to people than anything else, as they do not bite.
First of all, to you really have a fruit fly infestation? Fungus gnats and drain flies are also common at this time of year. Fruit flies are small brown or tan flies with reddish eyes. Adult fruit flies are, on average, about 3 or 4 millimeters long. You can tell the difference between fruit flies and drain flies by looking at their wings. Drain fly wings look like tiny moth wings, while fruit fly wings look similar to house-fly wings.
Eliminating fruit flies means eliminating their food sources. Despite their moniker, fruit flies like to eat all kinds of festering food bits, not just ripening fruit. Pretty much any food source will attract fruit flies, including little bits of fruit and vegetable scraps, unrinsed cans in the recycling bin, and dirty mop heads with food particles stuck on them. Fruit flies also like moisture. Moisture and organic material are the conditions that fruit flies need to reproduce. Drains that have a buildup of organic matter in them, and wet areas under sinks, are common breeding areas for fruit flies.
Pesticides won't help much in controlling fruit flies in the kitchen. What you need to do is eliminate food sources and breeding areas. Clean drains that contain organic matter buildup with a stiff brush. If drains are slow-moving, have them snaked by a plumber. Pouring bleach down the drain will not eliminate the ongoing problem of standing water and organic matter in the P-trap and organic matter coating the inside of the pipe, so it is not advised.
Kitchen cleanliness is key to reducing the presence of fruit flies. Be extra vigilant about washing dishes and getting all food scraps into the garbage. Make sure that you rinse cans and bottles, especially beer bottles and food cans, thoroughly before putting them in the recycling bin. Avoid allowing liquid to pool up at the bottom of the garbage can. Store all fruits in the refrigerator.
You can also set fruit fly traps after you've eliminated their food sources. There are a few ways to make fruit fly traps, but all of them operate similarly: A fruit fly trap is made of a jar, some bait, and a cover for the jar with a small hole in it. Some folks use a paper cone as the cover; some folks a plastic bag or plastic wrap with a small hole poked in it, secured tightly with a rubber band. Good baits are baker's yeast and sugar dissolved in warm water, vinegar, or red wine.