Flies are attracted to various substances that appeal to their senses of smell and taste. Understanding what attracts flies can help prevent infestations and allow for effective control methods. Some of the most irresistible substances to flies include decaying organic matter, sugary substances, vinegar, alcohol, and certain pheromones.
Decaying Organic Matter
Decaying organic matter, such as rotting food, animal feces, and garbage, produces gases and odors that are highly attractive to flies. The smell signals a food source to flies, prompting them to lay eggs in the decaying material so their larvae have a ready food supply. Common filth flies, including house flies, blow flies, and flesh flies, rely heavily on locating decaying organic matter to breed and feed. Keeping areas free of rotting materials is important for controlling fly populations.
Sugary Substances
Flies use taste receptors on their feet to locate sugary substances. Overripe fruit, spilled sodas, and food residue are strongly attractive. Sugary compounds resemble the natural food sources that flies prefer. The sweetness signals high caloric content to fuel fly metabolism and egg production. This is why flies swarm on sugary foods at picnics and other outdoor events. Storing ripe fruit properly and cleaning up spills helps keep flies disinterested.
Vinegar
Many flies find vinegar highly irresistible. They are attracted to its sweetness combined with acidity. Fermenting fruits naturally produce appetizing vinegar notes. Flies ingest organic acids like vinegar to supplement their diets with minerals, vitamins, and prebiotics that aid digestion. The smell of vinegar excites foraging urges in flies, making it a commonly used bait. Traps made with vinegar catch significantly more flies than water or sugar solutions alone.
| Fly Species | Vinegar Preference |
|---|---|
| Fruit flies | High |
| House flies | Moderate |
| Blow flies | Low |
Alcohol
Ethanol is formed during the fermentation process that creates vinegar. The alcohol content serves as an additional attractant to flies. Low concentrations draw in fruit flies, vinegar flies, and many filth fly species. However, higher alcohol levels can act as a feeding deterrent or even be toxic. Flies taste with receptors on their feet, allowing them to determine if an alcohol source is suitably safe for consumption and egg laying.
Pheromones
Certain pheromones are irresistible to flies. Pheromones are chemical compounds that insects produce to communicate with each other. Some pheromones have an aggregating effect, meaning they bring flies together on a food or breeding resource. The aggregation pheromones that flies secrete encourage more flies to join them. This clustering effect is visible around decaying materials where fly swarms form. Using synthetic fly pheromones allows effective trapping as a control method.
Effective Fly Attractants
Knowing which specific substances attract flies the most allows developing baits and traps to control infestations. Fly attractants fall into several major categories:
| Attractant Category | Examples |
|---|---|
| Decaying matter | Rotting fruit, animal feces, garbage |
| Sugary substances | Fruit juices, soft drinks, syrups |
| Vinegar | Apple cider vinegar, red wine vinegar, balsamic vinegar |
| Alcohol | Beer, wine, fermented fruit |
| Pheromones | Muscalure, trimedlure, z-9-tricosene |
Bait traps take advantage of these attractants to draw in and capture flies. Combining smelly, sugary, and acidic attractants creates irresistible traps. The aggregating pheromones increase trap effectiveness by recruiting more flies once the first flies arrive.
Why Flies Are Drawn to These Substances
There are biological and evolutionary explanations for why flies are attracted to decay, sugars, vinegar, alcohol, and pheromones:
– Decaying matter provides breeding sites and food sources for larval and adult flies. The smell signals ideal conditions for laying eggs.
– Sugary substances supply the carbohydrates that fuel flies. They prefer quick energy from sugars over proteins.
– Vinegar supplements fly diets with beneficial acids, minerals, and electrolytes. It resembles the juice of decaying fruits they evolved to feed on.
– Alcohol provides caloric content at low concentrations. High alcohol can intoxicate flies and impact predator avoidance.
– Pheromones enable chemical communication between flies about resources and mating. Certain pheromones have an aggregation effect.
Understanding these explanations allows leveraging attractants flies are evolutionarily programmed to seek out. Traps and baits take advantage of irresistible smells, tastes, and chemical cues that signal prime food or breeding sites to flies.
Most Attractive Baits
Fly traps and baits should contain a combination of attractants flies cannot resist:
Sugars – Sweet syrups containing sucrose, fructose, glucose are low-cost feeding attractants. Molasses and corn syrup are inexpensive sugar sources. A small amount of soap can reduce surface tension for better feeding.
Fruit – Overripe or fermented fruit releases volatile compounds that lure many flies. Bananas, pineapples, mangoes, and tomatoes make excellent attractants. Crush or slice fruits to expose more surface area.
Vinegar – Apple cider vinegar is highly attractive to most flies. Mix with fruit juice or puree for added effect. A few drops of dish soap helps break surface tension.
Alcohol – Beers and wines contain ethanol that flies sense from a distance. Fermented baits work best in initial fly attraction. Limit alcohol to 20-25% concentration.
Pheromones – Aggregation pheromones like Z-9-tricosene bring in more flies to traps. Use commercial formulations for optimal effect.
Yeasts – Live yeast converts sugars to alcohol and releases CO2. This fermentation process yields volatiles that mimic decay. Dry active yeast or wine yeast can be used.
Protein – Milk powders, eggs, meat, bone meal, and fish meal provide protein that attracts female flies seeking egg-laying sites. Limit protein sources to 5-10% of bait.
Most Effective Traps
Fly traps take advantage of irresistible attractants to draw in and capture flies:
Bag traps – Clear plastic bags containing attractant solution and baited with pheromones. Can catch thousands of flies over weeks or months.
Jug traps – Milk jugs or soda bottles converted into traps with attractant solution. Funnels and holes allow fly entry.
Cone traps – Inverted cone shape made of screen or plastic centered over attractant pan or wick.
Bottle traps – Partially filled plastic bottles with entry holes near the bait solution inside.
Strip traps – Plastic strips coated with sticky adhesive to catch flies attracted to bait.
Electric traps – Zappers or powered traps that electrocute flies lured in with UV light and attractants.
Position traps near fly breeding sites and resting areas. Use several traps for optimal control. Maintain traps regularly by replacing worn parts, sticky strips, and expired attractant solutions.
Conclusion
Flies are drawn to decaying organic materials, sugars, vinegar, alcohol, and pheromones for important biological and evolutionary reasons. These substances signal ideal conditions for feeding and breeding to flies. Traps and baits take advantage of irresistible attractants to effectively control fly problems through capture or toxicity. Combining sweet and sour baits that mimic rotting fruit with aggregating pheromones creates an irresistible trap. Continued research on fly attractants will further improve traps, baits, and integrated pest management programs for controlling fly pests.
