Black fly/Buffalo gnats can kill your small chicks (blood suckers)


11 Years
Apr 28, 2008
SW of Greenwood, INDIANA
Black Fly/Buffalo gnats- They're killing baby birds in many areas of the country.

The following is quoted from a friend of mine, Bob Flam, on another forum.

"...They're black fly/buffalo gnat... Pure vanilla works to disperse them, misted on the outside you have to do it twice a day..

Absorbine Junior works also, I do not know how long it last on the housing. Not something I'd want on babies.

Pyrethrin sprays will work, I don't know the toxicity of this, it's made from a flower...but only like .1%...the rest, I have no idea it's effects. Last year it was only effective part day also and had to be done twice if just sprayed on the outside of housing.

Absorbine Junior may be the best for lasting strength? I believe it's an oil, but not positive. A vanilla essential "oil" may last a whole day also...but I do not know. Absorbine junior is definitely something I personally would not want "directly" on my babies though, but it will keep em away. Don't know how long it last?"

Keep an eye out, they are out there and around....


Iowa State University Department of Entomology

We have been receiving a lot of calls regarding black flies over the past week. While we always get a few calls every year, this year the number of calls has been well above average. If I remember correctly, the last time we had a banner year for black flies was about 12 years ago. And, while most people want to blame the increased numbers on the floods and torrential rains we had this spring, that's not the case. To be honest, I'm not sure what has contributed to the problem this year, but it is not uncommon for any insect to go through a cyclic process where some years their numbers may be above average while some years it is well below average.

Here are some facts regarding the life cycle of black flies:

* Black flies only develop in fresh, running water. They do not develop in standing water sources like mosquitoes. And, black flies prefer to develop in rivers, creeks, and streams that have relatively clean water. Many have suggested that the increase in black fly populations nationwide may be the result of on-going efforts to clean up our rivers, creeks, and streams.
* Black fly larvae use a sucker-like device to attach themselves to rocks or other solid substrate in the streams. These larvae are filter-feeders that feed on plankton, bacteria, and other organic materials found in the water.
* Unlike mosquitoes where only the female feeds on blood, in the case of black flies both the male and the female feed on blood. On most animals, including humans, black flies prefer to feed around the facial area. Black flies will also feed around the wrists and ankles of humans.
* Black flies only produce one generation each year. In Iowa, and most of the country, the adults emerge in mid-June. Since they only produce one generation each year, all of the adults basically emerge at once and can produce large "swarms" overnight. Since it takes them basically a year to go through a life cycle, the adults that are active right now had their start last summer. Therefore, the rains and floods of this spring could not have been the contributing factor in the abundance this summer.
* Unlike mosquitoes that prefer to feed at dawn and at dusk, black flies prefer to feed in the middle of the day and prefer bright, sunny, warm, and windless days. That is one of the reasons why towns that may be fogging for mosquitoes at night will not notice any benefits in terms of black fly control. The time to be out fogging for black flies would be in the middle of the day when most people are also out and about, which obviously would not be looked on with favor by most of the town's people.
* The good thing about black flies is that since they only produce one generation each year, the adults will only be present and active for about 2-3 weeks each year. As a result, the black fly numbers here in Iowa should start to decline fairly soon.
* When black flies feed they inject saliva to prevent blood clotting. Our body's immune system perceives this saliva as a foreign protein and may respond to its presence in a dramatic fashion. Around the eyes, mouth, and ears this saliva may cause some fairly severe localized tissue swelling that may take 7-10 days to subside. While this is not a permanent or serious problem, it can be quite irritating and annoying.
* Black flies will feed on just about any warm-blooded animal, including birds. On poultry, their feeding is usually concentrated around the waddle and comb. While birds such as purple martins may not be too vulnerable as adults due to limited skin availability, young birds can be aggressively attacked. And, as you have noted, death in birds due to black fly feeding has been documented. This death may be the result of either anemia caused by extreme blood loss or anaphylactic shock caused by an immune response to the large amount of saliva that may have been injected during black fly feeding. Death may also arise from suffocation in ground-raised poultry when birds pile on top of one another in an attempt to avoid black fly feeding.

It has been my personal experience, and the experience of others, that the standard mosquito repellents containing DEET are not effective or reliable in repelling black flies. To be honest, there aren't any proven and effective commercial black fly repellents on the market. And, while I have heard reports about the success of using vanilla, Absorbine Junior, Listerine, and a host of other materials as a black fly repellent, we have no data or experience to either verify or deny these claims.

You indicated that one individual had recommended spraying the housing with pyrethrin and DEET. As I just mentioned, DEET doesn't work well as a black fly repellent. And, while pyrethrin also has some repellent properties as well as being an insecticide, any benefits from its use would be extremely short-term. In fact, pyrethrin has such low residual activity that it is usually recommended to be used on a daily basis. I wish I had a better recommendation for you, but to be honest, I don't. Using a pyrethroid insecticide such as those that contain the active ingredient permethrin, may provide slightly longer residual protection than using a pyrethrin spray. But again, there are no guarantees.

Hopefully, the black fly population will start to decline in the next few days. And, while their numbers are significantly higher this year, this does not mean that they will also be high, or higher, next year. A lot will depend on whether the rivers, creeks, and streams that are serving as the source of the black flies continue to flow clean and free the remainder of this summer, this fall, this winter, and next spring.
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