Greenhead Flies - Top 10 List of Questions from the Desperate

Greenheads are no joke. If you've been bitten by a biting fly then you already know the pain that these flies inflict. Yet, every summer like clockwork they show up and then suddenly disappear. They ruin family gatherings, quiet days and they infest the beach making it impossible to enjoy a day on the shoreline. Here are ten of the top questions asked by people who are desperate to avoid an encounter with greenheads.

Top Ten Questions from People Desperate to Avoid Greenheads

1. Which month do the greenheads emerge? Generally, the greenheads are out when the beach is at its best. Greenheads come out like clockwork the week of 4th of July every year in the Northeast.  They seemed to disappear around the middle of August at Plum Beach. Local weather plays a large role in when greenheads appear. Those beaches to the South are usually the first to feel the bite of the greenhead fly. Those areas more North feel that same sting a bit later in the season. If the beach if full of people then you can expect the greenheads to be present. Movement attracts them as these are visual hunters.

2. What do Greenheads Eat? Biting flies in general, have an interesting relationship - male to female. The males are vegan - they only eat plant juices. The female greenheads need for warm blood increases as she begins developing eggs. In fact, warm blood is an essential part of her breeding regiment. She needs the protein in the blood to develop a lot of eggs and healthy eggs. The good news - of sorts - is that she is not discriminating. She is happy with your blood. She will saddle up to a buffet of horse, cow, dog, sheep, deer, etc. At the beach, you don't see many of these other targets.

3. What good are Greenheads? In short, they are not good. They do not provide a benefit to mankind and when present in sufficient numbers, they can cause livestock to lose weight, get sick, and be anxious. They are also notorious for making people miserable.

4. When do Greenheads go away? Generally, greenhead populations are gone by the start of September. If the late spring is cold they may appear later. If the summer is mild, they might stick around into September. Don't worry. They will be back next June.

5. When do Greenheads Die? When they are stuck between your arm and your hand! Both deer fly and horse fly have a huge spike in their population in July and August. After that peak, the population begins to die off. The females have laid eggs and the next generation is developing for next year. As mentioned, if the summer is mild, the greenheads may linger into September. So, the Greenheads generally die by the end of August.

6. What Are Greenheads? Greenheads are large flies with vivid green eyes. They are part of the horse fly family and they are sheer terrors. The female issues painful bites so that she can drink your blood.

7. What Repels Greenheads? Short of a subharmonic force field, not much repels greenheads. They do not hunt primarily by smell, though that does play a small role in how they hunt. They are visual hunters, so, repellents do not work well with biting flies. What does work is a specialized trap - The Fly Cage - that turns the nature of these horror flies against them.

8. How do Greenheads Bite? The females are the only greenhead flies that bite. They have a specialized mouth that is much akin to a pair of scissors which she plunges into her victim. Once inserted, she opens the "blades" severing many of the small blood vessels. At the same time, she adds an anticoagulant to the wound so the blood flows quickly and constantly. She will only have a fraction of a second to lap up a blood meal and then dart off before risking death. Not to worry if you missed her... she will be back in a few minutes to wound you again.

9. How are the Greenheads at ______________ Beach? Usually, they are aggressive, hungry, and not shy. In terms of populations, they tend to be fewer in number in early June and early September. They are often more prevalent if a storm is approaching, and they are the worst during July and August.

10. Are Greenheads out at Night? No, not normally. It is possible that you could encounter greenheads at night but the situation would be very rare. These are visual hunters and they prefer to hunt in the brightest part of the day.

Do you have a question about Greenheads? Just ask in the comments and we will try to answer or include your question in a future blog.