What Are Deer Flies and Yellow Flies?
Many of us who work or play outdoors always seem to know when summer is right around the corner, because that’s when those annoying and usually painful bites occur from deer flies and yellow flies. These biting pests are among the most common types of flies in Florida, and their presence can swiftly turn a peaceful day outdoors into an uncomfortable, itchy, and painful ordeal.
Understanding these insects and how to protect yourself is key to enjoying the season. Ready to take preventative measures against biting flies? Learn more about deer flies and yellow flies with Florida Pest Control, the state’s residential fly control experts.
What Are Deer Flies and Yellow Flies?
Deer flies and yellow flies are both biting insects in the Tabanidae family. In their early stages, these pests are nectar feeders but become aggressive biters as adults, seeking a blood meal to complete their reproductive cycle.
Deer Flies in Florida: What You Need to Know
Deer flies (Chrysops) are medium-sized flies with dark bands on their transparent wings and striking, colorful eyes. They are most active in sunny environments, especially near ponds, swamps, or wooded areas. Female deer flies are the culprits behind those painful bites, as they use their sharp mouthparts to extract a blood meal essential for their reproduction.
Yellow Flies in Florida: Key Facts
Yellow flies (Diachlorus ferrugatus) are slightly smaller than deer flies. They are characterized by their yellowish body and bright green or golden eyes. Like deer flies, female yellow flies bite to obtain the nutrients they need to lay eggs. These pests are particularly aggressive during the late afternoon and thrive in warm, humid conditions, making Florida an ideal habitat.
How to Identify Deer Flies and Yellow Flies in Florida
Identifying deer flies and yellow flies is crucial for understanding how to avoid them and manage their bites effectively. These flies share similarities but also have distinct features and behaviors that set them apart.
Physical Characteristics of Deer Flies and Yellow Flies
Deer flies are easily recognized by their distinctive wing patterns and vibrant, multicolored eyes. Yellow flies, on the other hand, have a uniformly yellow body and translucent wings. Both species have strong, fast-flying abilities and can be quite persistent when seeking a host. While they share some similarities, each has distinct physical features that make them recognizable. Here’s a closer look at how to identify these pests:
Deer flies (Chrysops species):
- Medium-sized flies with a body length of about 1/4 to 1/2 inch.
- Transparent wings with dark, distinctive bands or patterns.
- Eyes are brightly colored and often display a metallic green or gold appearance with intricate patterns.
- Body colors vary but typically include shades of yellow, black, or brown.
Yellow flies (Diachlorus ferrugatus):
- Slightly smaller than deer flies, with a length of about 1/3 inch.
- Uniformly yellow or golden body with translucent wings.
- Eyes are vibrant green or golden, giving them a striking appearance.
Behavior and Habits of Biting Flies in Florida
These insects are known for their aggressive feeding behaviors and specific activity patterns. Both deer and yellow flies are most active during warm, humid weather, with their behavior largely influenced by the time of day and environmental conditions. They are often found in large numbers near wetlands, swampy areas, and other moist habitats.
Life Cycle of Deer Flies and Yellow Flies
From egg-laying to adult emergence, these insects undergo several distinct stages, each adapted to their swampy or moist habitats.
Breeding and Egg-Laying Habits
Females lay their egg masses on aquatic plants or over moist, swampy soil. A single female can lay up to 1,000 eggs, often clustering them on vegetation above water. Before breeding, male flies are usually the first to emerge and wait around for the females. When mating is completed, the female is ready to seek out a warm-blooded host. She injects an anticoagulant into the wound and then sops up the blood with her sponge-like mouthparts.
Development Stages: From Larva to Adult
A female deer or yellow fly tends to lays her eggs preferably on aquatic vegetation above water or saturated soil. She could lay as many as one thousand eggs. The eggs hatch within a week, releasing larvae that drop into the moist soil below and as the larvae hatch, they fall to the moisture below where they will feed on an organic matter they find in the wet soil. When the larvae are ready to pupate, they move to a drier area of the soil. After moving to drier soil, the flies enter the pupal stage for about three weeks before emerging as adult flies. Males typically emerge first, waiting to mate with the females.
Yellow Fly and Deer Fly Season in Florida
Florida’s warm, humid climate makes it a paradise for many, but it also creates perfect conditions for deer flies and yellow flies to thrive. These biting pests emerge in large numbers during the state’s hottest months, turning outdoor activities into itchy, painful ordeals if you’re not prepared.
In northern Florida, mosquito season usually starts in March, with the most mosquitoes appearing in late spring and summer. In southern Florida, mosquitoes can be active almost all year because of the warmer weather. They are worst during the rainy season, from June to October.
When Are Yellow Flies Most Active in Florida?
Yellow flies are most active from late spring through summer, typically between May and August. These pests are particularly aggressive during the late afternoon and early evening when the heat subsides. Their favorite feeding grounds include shaded, swampy areas and heavily wooded regions where they can wait for warm-blooded hosts.
Seasonal Patterns of Deer Flies in Florida
Deer flies follow a similar seasonal timeline. Activity normally begins in late May and continues through September. A female deer fly’s favorite feeding time is two or three hours after sunrise – and then again for a couple of hours before sunset, with activity peaking in sunny, humid weather. These particular pests prefer environments near ponds, swampy areas, or wooded trails, where they target humans, pets, and livestock with their painful bites. Planning outdoor activities earlier or later in the season, avoiding peak biting hours, and wearing protective clothing are some of the best ways to avoid these pesky flies.How Deer Fly and
Yellow Fly Bites Impact Humans and Animals
Bites from deer and yellow flies are more than just an annoyance— they can cause significant discomfort for humans and animals. The bites can be painful and often lead to itching, swelling, and in some cases, allergic reactions.
Symptoms and Reactions to Yellow Fly Bites
Yellow fly bites are particularly aggressive and painful. The fly’s saw-like mouthparts cut into the skin, allowing it to feed on blood. Common symptoms include:
- Severe itching and irritation at the bite site.
- Swelling and redness that may last for several days.
- In some cases, allergic reactions characterized by excessive swelling, hives, or difficulty breathing.
For pets and livestock, bites can cause restlessness and scratching, with swelling appearing near ears, legs, or other exposed areas. If symptoms persist or worsen, consult your pet’s veterinarian.
How to Manage Deer Fly Bites
Managing deer fly bites effectively can help minimize discomfort and reduce the risk of infection. According to Medical News, here’s what you can do:
- Clean the bite area: Wash the site with soap and water to prevent infection.
- Soothe irritation: Cover with a cold washcloth to help with swelling and pain, and soothe inflammation.
- Take oral anti-itch medication: Over-the-counter anti-itch medicines or pain relievers can alleviate severe itching.
- Avoid scratching: Scratching can break the skin and lead to secondary infections.
Are Biting Flies in Florida Dangerous?
While relatively rare, yellow flies and deer flies in Florida can pose a health risk by transmitting diseases such as Tularemia. This bacterial infection can cause symptoms like fever, skin ulcers, swollen lymph nodes, and in more severe cases, respiratory issues. If you experience any of these symptoms after being bitten, it’s important to seek prompt medical attention.
Beyond disease transmission, the painful bites from these flies can lead to severe itching, swelling, and even allergic reactions in some individuals, further emphasizing the importance of prevention. If you’ve experienced an adverse reaction to a fly bite, contact a medical professional.
Taking steps to avoid bites, such as using repellents with DEET and wearing protective clothing, is essential to minimize the risks associated with these pests. For pets, protective sprays and fly-repellent covers can offer additional protection. For the best results, ask your pet’s vet for topical recommendations.
Our team at Florida Pest Control is dedicated to providing expert solutions for all types of pests—including those pesky biting flies. If you’re dealing with a fly infestation, contact us today.
How to Prevent Yellow Flies and Deer Flies in Florida
Prevention is key when it comes to dealing with yellow flies and deer flies. By taking proactive steps, you can reduce your exposure to these biting pests and make outdoor activities far more enjoyable.
Personal Protective Measures Against Biting Flies
Protecting yourself from bites begins with simple but effective strategies:
- Dress smart: Wear long-sleeved shirts, long pants, and light-colored clothing to cover exposed skin and deter bites.
- Use insect repellents: Apply products containing DEET, picaridin, or other effective repellents to your skin and clothing.
- Avoid peak activity times: Limit outdoor activities during the late afternoon, early evening, or sunny mornings when these flies are most active.
- Set up sticky traps: Use creative solutions like blue Solo cups or black beach balls coated with adhesive to attract and trap biting flies around your property. These low-cost traps are surprisingly effective in reducing fly populations.
While these tips can help you manage flies on a smaller scale, achieving full prevention often requires professional expertise. At Florida Pest Control, we utilize advanced tools like our eco-friendly Lumnia light traps to capture and reduce fly populations in your outdoor spaces.
Controlling Deer Flies and Yellow Flies in Your Environment
Managing the environment around your home can significantly reduce the presence of deer and yellow flies alike. One effective approach is eliminating standing water, such as swampy areas, ponds, or other stagnant water sources, where these flies breed and lay eggs. Ensuring proper drainage and maintaining dry areas around your property can disrupt their life cycle.
Another important step is to trim vegetation regularly. Keeping grass and shrubs well-maintained minimizes shaded habitats where deer flies and yellow flies like to rest and hide. Reducing these areas makes your surroundings less inviting for these pests.
Interested in learning more about how we tackle other fly species? Check out our article: Keeping Filth Flies at Bay.
Do You Have a Fly Infestation Problem? We Can Help.
Our team of professionals at Florida Pest Control assesses your property, identifies problem areas, and implements targeted solutions such as insecticide treatments or habitat modifications. Contact us today for help with deer flies or yellow flies.
