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| https://www.flickr.com/photos/32977858@N02/15171172927/ A different but related species of blackfly | . Photo Credit: Tony CC some rights reserved |
As
winter is finally coming to a close and spring is drawing near, we cannot wait
to open up their windows and complete, what seems to be, our endless
hibernations. As those arctic temperatures begin to disappear and the
atmosphere starts to warm up, it can only mean one thing… No, it doesn’t mean
it’s time to break out your sunscreen and beach umbrella! It means it is time
to prepare for the emergence of the beloved black fly; or as we like to call
them here in the Lehigh Valley, gnats! Okay,
so maybe these little guys aren’t the most lovable creatures, but as the
weather becomes warmer, their presence is almost guaranteed.
What we know as gnats are actually black flies. The black flies that we do have here in the
Lehigh Valley all belong to the same species: Simulium jenninsi! Although they are not the most diverse group of
insects, the Black Fly does have over 1,800 known species. They can be found in
all corners of the world and in a variety of climates. In North America they stretch from the Pacific to the Atlantic,
however, they have a higher diversity and abundance in the northern regions. Here
in the Lehigh Valley, we have grown very accustomed to the presence of the
Black Fly as they just about overwhelm Pennsylvania citizens from the Summer
into early Fall.
Black Flies lay their eggs in running water, which is one reason that they are commonly found near wet and moist areas. Their exoskeletons are extremely sensitive as they develop; thus, polluted water isn’t always the best environment for these critters. After they molt into adults, Black Flies are typically terrestrial but do stay close to wetter areas, and similar to mosquitos, tend to congregate around stagnant and small bodies of water. This makes streams, creeks, and rivers a very popular hangout for the gnats. However, this does not mean that they are only found near water sources. Here in the Lehigh Valley black flies are often times found in terrestrial areas, miles away from their original sources of water. Curious as to how to identify a gnat from other black flies? Well, to be completely honest, it is pretty difficult to do without a microscope! But as a general rule of thumb, they are very tiny and appear to have a dark brown or black coloration. Just a general rule of thumb, if it is really small, not a mosquito, and trying to nibble at your toes, it is probably a gnat!
Now that we can identify what a black fly looks like, I’m sure the question on your mind is, “what on earth do they eat?” As youngsters, these little guys act as filter feeders; eating debris in the water and algae off of rocks, they eat whatever happens to come floating past. Once they emerge from the water in their adult forms, males and females have different diets. Males will generally feed on nectar from flowers and plants, while females will go for blood… literally! Different species of Black Flies prefer their blood meals from different organisms. This is the reason why we feel them nibbling at us during soccer practice!
Whether you call them by their true name (black flies) or their most common nickname (gnats), we all know that they can be pests to the human population. Their tiny bites leave an itching sensation that leads to the human hand to become a fly swatter that swings without mercy. Black Flies do not typically cause sicknesses, however, since they are blood- suckers they can act as vectors for disease. However, do not be alarmed! These sicknesses are not found here in the Lehigh Valley, or anywhere in the United States. So although gnats may be annoying they are not threatening to our health! For most of us here in the Lehigh Valley, the only true threat they cause to public health is an allergic reaction that we can get from their bites.
Pennsylvanians are no strangers to the infamous Gnat; in fact we have the largest program to biologically control the population of Black Flies in the United States. Within the Lehigh Valley area, there have been record -breaking numbers of Black Flies acting as pests for years. A few years back, a biological control was implemented in order to help control the overwhelming amount of gnats in the area. Bacillus thuringiensis israelensis is a type of bacteria that is naturally occurring and targets specific types of Black Flies. And you guessed it, the little guys that we have around here are within that small group. Therefore, when the biological control program was implemented a few years back, the population size and nuisance of the Gnats significantly decreased, allowing the citizens in the Lehigh Valley to enjoy the warm outdoors in peace. This government-funded program was unfortunately cut as the economy began to decline and the community became concerned about the use of bacteria in the environment. However, not many people know that this specific bacterium is can naturally occur in soil and was originally discovered in a soil sample from Israel and it does not actually have a dangerous effect on us humans, our pets, or other organisms. Therefore, when the government funding for the fly control program was cut and the gnats returned with gusto!
Now as the temperatures rise, beware as a few of your not so friendly bug buddies may begin to start nipping. So, next time, before you slap at a fly swirling around during a soccer game, or zap a gnat when you are hiking and camping with friends near a creek, try to send a little sympathy to the little gnats as we have a new understanding for what they are all about!
This post by Emily Rybnick is licensed under aCreative Commons Attribution 4.0 International License.
Black Flies lay their eggs in running water, which is one reason that they are commonly found near wet and moist areas. Their exoskeletons are extremely sensitive as they develop; thus, polluted water isn’t always the best environment for these critters. After they molt into adults, Black Flies are typically terrestrial but do stay close to wetter areas, and similar to mosquitos, tend to congregate around stagnant and small bodies of water. This makes streams, creeks, and rivers a very popular hangout for the gnats. However, this does not mean that they are only found near water sources. Here in the Lehigh Valley black flies are often times found in terrestrial areas, miles away from their original sources of water. Curious as to how to identify a gnat from other black flies? Well, to be completely honest, it is pretty difficult to do without a microscope! But as a general rule of thumb, they are very tiny and appear to have a dark brown or black coloration. Just a general rule of thumb, if it is really small, not a mosquito, and trying to nibble at your toes, it is probably a gnat!
Now that we can identify what a black fly looks like, I’m sure the question on your mind is, “what on earth do they eat?” As youngsters, these little guys act as filter feeders; eating debris in the water and algae off of rocks, they eat whatever happens to come floating past. Once they emerge from the water in their adult forms, males and females have different diets. Males will generally feed on nectar from flowers and plants, while females will go for blood… literally! Different species of Black Flies prefer their blood meals from different organisms. This is the reason why we feel them nibbling at us during soccer practice!
Whether you call them by their true name (black flies) or their most common nickname (gnats), we all know that they can be pests to the human population. Their tiny bites leave an itching sensation that leads to the human hand to become a fly swatter that swings without mercy. Black Flies do not typically cause sicknesses, however, since they are blood- suckers they can act as vectors for disease. However, do not be alarmed! These sicknesses are not found here in the Lehigh Valley, or anywhere in the United States. So although gnats may be annoying they are not threatening to our health! For most of us here in the Lehigh Valley, the only true threat they cause to public health is an allergic reaction that we can get from their bites.
Pennsylvanians are no strangers to the infamous Gnat; in fact we have the largest program to biologically control the population of Black Flies in the United States. Within the Lehigh Valley area, there have been record -breaking numbers of Black Flies acting as pests for years. A few years back, a biological control was implemented in order to help control the overwhelming amount of gnats in the area. Bacillus thuringiensis israelensis is a type of bacteria that is naturally occurring and targets specific types of Black Flies. And you guessed it, the little guys that we have around here are within that small group. Therefore, when the biological control program was implemented a few years back, the population size and nuisance of the Gnats significantly decreased, allowing the citizens in the Lehigh Valley to enjoy the warm outdoors in peace. This government-funded program was unfortunately cut as the economy began to decline and the community became concerned about the use of bacteria in the environment. However, not many people know that this specific bacterium is can naturally occur in soil and was originally discovered in a soil sample from Israel and it does not actually have a dangerous effect on us humans, our pets, or other organisms. Therefore, when the government funding for the fly control program was cut and the gnats returned with gusto!
Now as the temperatures rise, beware as a few of your not so friendly bug buddies may begin to start nipping. So, next time, before you slap at a fly swirling around during a soccer game, or zap a gnat when you are hiking and camping with friends near a creek, try to send a little sympathy to the little gnats as we have a new understanding for what they are all about!
This post by Emily Rybnick is licensed under aCreative Commons Attribution 4.0 International License.
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