Fruit flies are serious contaminators of food along with being an annoying pest to have as well. Other names for them are banana flies, vinegar flies, sour flies, pomace flies, and vinegar gnats. The adult fruit flies may be a dull yellow color, a brownish yellow, or a brownish black color, and are smaller than half an inch long. The larvae are dirty white, maggot shaped, and very small as well. You may see large populations of fruit flies appear quickly in hotels, cafeterias, restaurants, and other food establishments too. Frequently invaded structures or areas also include truck crop acreages, the vicinity of orchards, vineyards, and more. These fruit flies are considered to be the biggest pest in food processing plants, including dehydrators, pickle plants, wineries, and canneries. They cause the highest percentage of contamination of fruit products, which is also cited as a contaminating agent in the reports of food seizures. The reports were made by the US Food and Drug Administration (FDA).
Female fruit flies can lay up to 500 eggs at a time and will do so on rotting fruits and vegetables. The larvae will feed on fungi growing in infested material and yeast organisms. Soon, they will turn their food into a semi liquid-like “mess" which can help when trying to find the breeding site. As the larvae become full grown, they leave the food material for dryer areas. In the summer, it can take 8-10 days for an egg to become an adult and mating then takes place immediately. This means that egg laying can start all over again in just 24 hours from becoming an adult.
To control the fruit flies from taking over your fruits and vegetables, in the warmer seasons you should screen all openings to the outside with a mesh screen or netting. Food like fruit salads, jams, jellies, pickles, fruit juices, etc., or cut/spoiling fruits and vegetables should not be left exposed in open containers. It is best not to have large quantities of raw fruits and vegetables like potatoes and onions exposed as they can attract a fruit fly infestation. It’s also good to always check the big bags of food because one rotten vegetable could be at the bottom of the bag and that one vegetable would be enough to support an infestation. Keep exposed food in cold storage if possible, to slow down the development of larval fruit flies. Any overripe fruit or vegetable that you may have, should be removed to avoid recurrence of the fruit flies. The breeding areas can be difficult to locate sometimes, including places like an apple accidentally being kicked under shelves of a pantry, a forgotten potato in a storage bin, or improperly cleaned garbage cans or disposals. Believe it or not, breeding areas have also been found to be beer cans, soft drinks, or milk containers with remaining liquid in the bottom. Rags and uncleaned mops can also serve as a breeding site for fruit flies if they were used clean up any drink or food. Basically any food materials found under counters, baseboards, in the cracks around drainboards, or cracks around sinks can also be a way for the flies to start an infestation. A way to get rid of a lingering flies would be to use a pesticide aerosol spray or even a fly swatter. You can also construct a trap by creating a paper funnel, placing it into a jar with some cider vinegar bait and this will attract the adult flies.