Flies are drawn to certain colors more than others. Understanding which hues flies are attracted to can help prevent infestations by avoiding using those colors for outdoor decorations or leaving those colored items outside. This article will examine what research says about fly color preferences and provide tips for deterring flies based on this information.
Quick Answer Summary
Flies are particularly attracted to the colors yellow, orange, red, purple, blue, and black. Shades like yellow and orange especially draw in flies. The reason certain colors attract flies more than others has to do with fly vision and preferred food sources. Flies see better in the yellow-green and blue-violet end of the color spectrum, so those hues stand out to them. And many flies feed on reddish or dark decomposing matter, so those related colors also catch their attention.
How Fly Vision Impacts Color Preference
A key factor in understanding fly color attractiveness is fly vision. The eyes of various fly species are specially adapted to noticing certain colors more than others.
Research has shown that flies have photoreceptors tuned for green, blue, and ultraviolet light. They are especially sensitive to wavelengths in the yellow-green and blue-violet parts of the color spectrum. Yellow, orange, and purple hues contain wavelengths flies pick up on easily.
For instance, one study on house flies found they responded most strongly to the colors yellow and orange. These warmer colors elicited the highest electrical signals in fly photoreceptors compared to blue, green, and purple.
Another study of biting horse flies looked at reactions to different colored targets. The flies were most attracted to surfaces with hues in the creams, reds, and blacks. Yellow paper also attracted a large number of flies.
So fly vision is built to readily notice the warmer yellows and oranges as well as the cooler purples and blues that contain wavelengths their photoreceptors detect. This heightened visibility draws flies toward those colors.
Preferred Food Sources
In addition to color visibility, flies head for hues associated with their beneficial food sources. Many flies feed on decaying organic matter, wounds on animals, and animal feces. These food sources contain reddish, purple, blue, and black pigments.
For example, different species of flesh flies and blowflies taste and smell for decomposing meat so they can lay eggs on it to nourish larvae. The dark colors signs of decay. Horse flies look for dark hosts to bite like cattle or humans. And bottle flies and house flies feed on feces which can be dark or reddish in color.
So these fly species have learned to associate the colors found around their preferred food sources with places to fulfill their nutritional needs and reproductive goals. This further explains their attraction to darker and more reddish-purple hues.
Research on Colors that Attract Flies
Various research studies have dug into reactions flies have to different colors. The key findings on fly color preference are summarized below:
| Study | Fly Type | Methods | Colors Tested | Most Attractive Colors |
|---|---|---|---|---|
| Pickens (1991) | House fly | Colored card targets | Yellow, orange, blue, green, purple | Yellow, orange |
| Agee & Patterson (1983) | Stable fly | Colored panel traps | Yellow, green, blue, black, white | Yellow |
| Zeil (1983) | Blowfly | Colored card preference | Yellow, orange, blue, green | Yellow, orange |
| Briscoe & Chittka (2001) | House fly | Color stimuli reactions | Blue, green, yellow | Blue, Green |
The house fly studies found yellows and oranges to be the most attractive. Yellow also drew in many stable flies, while blowflies went for yellows and oranges as well. The last study differed in finding blue and green most exciting for house flies, perhaps due to differences in methodology and colors tested.
But overall, warmer yellows, oranges, and reds appear most attractive across fly groups along with some purples and blues. Darker blacks and browns are also fly magnets, matching their food sources. These colors should be avoided around the home to discourage flies.
Tips to Deter Flies Based on Color Preferences
Here are some tips for repelling flies using knowledge of which colors they flock to:
- Avoid having outdoor yellow and orange decorative items, tableware, or upholstery.
- Choose blue, white, or light green instead for outdoor place settings and decor since these are less attractive.
- Don’t wear yellow, orange, red, or dark purple clothing when spending time outdoors.
- Select light blue, tan, or green clothing hues that flies don’t gravitate towards.
- Pick light-colored mesh screening for windows and doors rather than darker screens.
- Install yellow bug lights that attract fewer insects.
- Remove ripe red berries and rotting fruit from gardens right away.
- Promptly clean spilled dark sodas, purple juices, or red wines outdoors.
- Store brown compost bins as far from outdoor seating areas as possible.
- Pick up animal waste which can have darker coloring promptly.
Avoiding fly favorites like yellow and orange and going for lighter or neutral tones can make a yard, patio, or deck less inviting. Reduce food sources with dark reddish hues as well. With some color-wise precautions, flies looking for places with their ideal colors will move on.
Flies Most Attracted to Certain Colors
Certain fly species seem especially attracted to particular colors based on their feeding behaviors and habitat preferences.
House flies – Drawn strongly to yellows, oranges, reds, and purples. Like warmer hues found in decaying matter.
Stable flies – Attracted to yellows associated with grazing animals they bite and animal waste.
Flesh flies – Go for reds, blues, and blacks that signal decomposing meat they lay eggs in.
Blowflies – Prefer warmer yellows and oranges of decaying material to deposit eggs.
Bottle flies – Head for darker browns and reds indicative of feces they eat.
Scuttle flies – Drawn to darker blacks, browns, and reds found in moist decaying vegetation.
Fruit flies – Gather around ripened yellow, orange, and red flesh fruits with fermenting sugars.
So each fly has colors they’ve learned provide their preferred food sources. Avoiding those hues around the home can make it less inviting for specific fly types.
Flies Attracted to Color Combinations
Fly color attraction can interact in complex ways. Sometimes multiple hues together attract more flies than a single color alone. This is due to how flies perceive color combinations.
Studies find some flies most responsive to color contrast – a darker color adjacent to a lighter color, like black on yellow. Dark centers with lighter outer rings also get fly attention.
For instance, one study looking at trap effectiveness found that mingling colors like yellow and black attracted the most stable flies. The contrast of light and dark in proximity is highly visible and indicates beneficial resources to flies.
Research also shows flies gather around flower centers more when they have darker spots. This suggests flies hone in on contrasting dark areas surrounded by light. They may associate this with nectars and pollens to feed on.
Based on these findings, using solid light colors without contrasting dark accents or color mixing could be a good deterrent. Avoid groupings with a strong color contrast like yellow tableware on a dark tablecloth outdoors.
Impact of Color Saturation on Attractiveness
Another facet of color that impacts fly attraction is saturation. Studies find flies respond more strongly to highly saturated or vivid shades of their preferred colors compared to diluted or muted versions.
For example, brightly saturated yellow attracted over twice as many flies compared to a pale faded yellow in one experiment. The saturated yellow had higher color purity and intensity.
Similarly, a vivid red card was significantly more attractive to flies versus a pink card. The deeper crimson red had greater color saturation.
This shows that deeper, richer shades of red, yellow, orange and other fly favorites generate greater interest. Using washed-out or light tints of those colors can make surfaces and items less conspicuous.
How Temperature Affects Fly Color Preference
External temperature also influences fly reactions to color. When it’s cooler out, flies shift their color preferences.
At lower temperatures, fly vision changes. Certain photoreceptors become less sensitive while others remain active. This alters how stimulating flies find different wavelengths of light.
Research on house flies showed they were most attracted to blue cardboard at cooler temperatures. But when temperatures increased, yellow became more appealing. Blue shifted down below red in attractiveness.
Temperature mediated these color response hierarchies. Colder weather made blue more exciting while warmth enhanced yellow’s appeal. Green remained moderately attractive across temperatures.
So season and weather can impact what colors flies zero in on more outside. In cool weather, warmer yellows may become less important than blues. This interaction between temperature and color should be considered.
Impact of Age on Fly Color Preferences
A fly’s age also change its color preferences. Younger adult flies are more attracted to shorter wavelengths like blues and greens. As flies grow older, they become more sensitive to longer yellow and orange wavelengths.
For instance, tests of blowfly color choice found younger flies preferred blue over other hues. But as the flies aged over three days, their preference shifted to favoring yellow and orange more. The older flies still reacted to blue but liked it less.
This same pattern was seen in experiments on houseflies. Younger flies were excited by blue cardboard while mature flies danced around a yellow target instead.
The developing fly eye undergoes changes as the fly matures which alter color sensitivities. This can cause shifts from liking blues more initially to favoring warmer yellows and oranges more later in life.
Fly Color Discrimination Abilities
Recent research also indicates flies can discriminate between colors and not just respond to them reflexively. This shows flies have color vision allowing them to differentiate hues.
Studies training flies with colored light rewards found they could learn to match a certain color light with a sugar reward. The flies demonstrated the ability to actively select the previously rewarded color from alternatives in follow-up trials.
So flies do not just blindly fly at specific colors. They have some capacity to perceive variations between hues and associate colors with good or bad experiences. Their color seeking behaviors have some intent behind them.
Impact of Color on Fly Feeding
Color not only draws flies to surfaces but also influences feeding behaviors. Different colors can encourage or discourage fly eating and vomiting once they land.
Experiments putting dyed sugars on plates revealed flies consumed more blue-colored sugar. Blue elicited the most eating compared to red, green, or yellow dyed sugars. The blue color really stimulated fly appetite.
However, yellow dyed sugar induced the most regurgitation once consumed. The yellow color triggered fly vomiting reflexes. The yellow may mimic toxins or spoiled food in nature that flies evolved to reject.
So color impacts not just initial fly attraction but also feeding behaviors. Blue surfaces might encourage flies to stick around and eat more, while yellows prompt vomiting and leaving.
Impact of Color on Fly Reproduction
Color also has implications for fly mating and reproduction. Female flies assess coloration when choosing mates and laying eggs.
Studies find female flies more attracted to bright yellow males and prefer mating with them. Females also select yellow leaves more often to lay eggs on.
The preference for yellows suggests flies associate the color with healthy potential mates and good nutrition for offspring. Yellow’s associations trigger attraction and reproduction behaviors.
So fly color choices extend beyond just feeding to also impact mating and reproduction. This further cements fly color preferences into their genetics over successive generations.
Fly Color Attraction Summary
In summary, key research findings on fly color preferences include:
- Flies see yellow, orange, blue, and purple wavelengths clearly due to their eye structure.
- Yellow, orange, red, and darker colors attract flies due to associations with food sources.
- Strong color contrasts and patterns boost attractiveness, while solid light colors deter flies.
- Saturated or vivid versions of colors are more effective at drawing flies.
- Cooler temperatures make flies prefer blues more while warmth enhances preference for yellow.
- Younger flies favor blues and greens while mature flies like yellows and oranges more.
- Flies have some color discrimination abilities beyond just reflexive attraction.
- Color impacts feeding, with blue stimulating eating and yellow causing vomiting.
- Females choose to mate with yellow males, seeing the color as indicating healthy mates.
These insights into fly color vision, preferences, and behaviors can help guide strategies to make areas less enticing. Avoiding their favorable colors while using less attractive hues can discourage flies from swarming.
Conclusion
Flies detect and seek out certain colors more than others due to aspects of their visual systems and color associations with beneficial food sources. Yellows, oranges, reds, and blues/purples tend to most attract flies. Deep, saturated versions of these colors are most stimulating.
Cooler temperatures make flies favor blues more while warmth enhances preference for yellow and orange. Younger flies go for blues initially, while mature flies shift toward liking yellows and oranges more. Color combinations with contrast also attract flies.
These color attractiveness factors relate to fly needs to find food, mates, and laying sites. Strategic use of less attractive colors like greens, tans, and light grays can help make outdoor living spaces, entrances, and gardens less enticing to flies. Avoiding fly-friendly colors reduces nuisance flies and improves time spent outdoors.
