The scene is a common one; you are
sitting outside on a warm summer evening with the porch light glowing. A moth
flutters by, catching a glimpse of the light. He begins to float toward the
light, seeming unaware of his imminent demise. As he reaches the light, he
ceases flying and falls to the ground, ending his time on earth.
This
behavior is one we see fairly often. It has even been used to create traps to
attract and kill moths and other insects. The question is, why do moths engage
in such detrimental behavior? Clearly, the outcome is not a positive one for
the moth. Recently, scientists have begun to examine this odd behavior and why
it might be occurring. According to one article, there are a few common hypotheses being explored regarding why
moths may engage in such seemingly counter-intuitive behavior. Some of the
reasons include the moths believing that the light source is actually the moon,
the dark space around the light providing a seemingly good hiding place for the
moth, or the light actually temporarily blinding and disorienting the moth.
While all of these hypotheses seem like reasonable ones, more explorations need
to be done in order to determine the true root cause of this behavior.
It should
also be noted that not all moths engage in this action. After a recent study
exploring moths from different habitats, it has been found that exposure to
light pollution plays a role in the tendencies of moths to fly towards light.
It appears that moths who live in habitats with high levels of light pollution
have learned to refrain from engaging with light sources while moths from
darker areas with less light pollution are naive, and hence more likely to fly
towards artificial light sources when exposed to them. While it might seem
strictly positive that moths are learning not to engage in behavior resulting
in their death, there may be larger evolutionary consequences to this change in
behavior. If moths evolve to not fly toward light sources, it is worried that
animals that prey on them may lose a vital source of food when moths are not
flying in the open as often. This is just one effect that this change in
behavior could have and who knows what else may follow.
So next
time you are enjoying the night sky while sitting on your back deck and you see
a moth being lured toward the light, maybe you’ll begin to wonder “what is
going through this moths mind right now”. Or maybe you won’t, but I certainly
will.
Posted by Jamie Downer
(1)
I always wondered what attracted the bugs to our deck lights! Do you think that if some moths are able to learn not to fly towards the lights that this type of behavior could be passed down from generation to generation eventually eliminating all moths from flying into lights? Do you know if this is the reason all insects fly towards the light or are these hypotheses just focused on why moths do it?
ReplyDeletePosted by: Katarzyna Mosio
Hi! Thanks for your comment! According to the article, it seems that the behavior is one that can be passed down from generation to generation as the experiment was conducted on moths that were removed from their environment as larvae. Because the moths were not in an environment where they would learn the behavior, it seems that the level of light attraction has a genetic basis. I don't believe that all moths will evolve this behavior as light pollution seems to be involved in the development of this behavior. It could be that as long as their is light pollution, there will be moths that are attracted to light. As for other insects and this behavior, the moon hypothesis seems to come up a lot across multiple species. Because many bugs use natural light sources as navigational guides, the artificial lights can confuse bugs of all kinds!
DeletePosted by Jamie Downer (1)
It's fascinating that months are adapting to light in high light pollution areas. Would it be evolution of the months because it has been several generations since they lived in the light polluted area for several generations? It's interesting that humans have impacted a population of animals, that we were not conscious of, which in turn affects the predators that need moths for food.
ReplyDeleteRachel Klett
I was surprised to learn that scientists hadn't studied this strange phenomenon earlier! One would assume that research on such a well-known behavior would have been previously conducted in order to learn more about moth's evolutionary roots. I am curious whether the selection pressure in areas will less light pollution will be strong enough to eventually cause a change in behavior.
ReplyDeletePosted by: Hayley Fecko
This is such an interesting topic and one I definitely would not have thought to look into. I also loved the opening scene you painted as it is one we all know well. I enjoyed hearing the different theories on why moth's do this. I wonder if this is something we will ever really be able to know as it seems somewhat abstract. I was also wondering what you think is the most probable answer to this question of moth's behavior?
ReplyDeletePosted by Alexandra McGuire
I'm so glad that you enjoyed the opening! Although the behavior does seem abstract, I think that the ultimate true cause of the behavior will be determined, especially if it is determined to have a genetic basis. With all of the technology available today surrounding genome processing and editing, I think the cause of the behavior will be determined, if it hasn't already! As for what I think is the cause of this behavior, I tend to lean toward the moon hypothesis, as it seems to have the most scientific evidence and evolutionary backing!
DeletePosted by Jamie Downer (1)
Since moths that live in an area with high light pollution are less likely to fly into lights while low light pollution moths fly into the lights at a higher frequency is it also possible that different species of moths are attracted to lights more often then other species? Has a study been conducted by using different species of moths and seeing how often each one flies into light? I think it would be interesting to include different species in a different study if done.
ReplyDeletePosted by "Edwin Montecinos"
This was quite interesting to read about, because I had never even thought about why moths would fly towards the light. Do you think it's a similar concept to how deers or other animals may run toward car headlights, and that usually ends in their deaths as well? I know that the animal would be blinded as the headlight shines directly into their pupils, but why do they go toward that light in the first place thinking that it is okay. At least when it comes to a moth flying towards the light, there wouldn't be damages like a deer ramming into your car. The behavior of these animals make me wonder if they're just not capable of understanding danger in front of them yet, and whether or not they can start to understand and adapt, then passing on to younger generations that this action is not safe.
ReplyDeleteI am just realizing that my comment never posted for some reason! I have never heard of deer running toward light! I was under the impression that the light simply stunned them, preventing them from moving out of the way! However, if they do exhibit that behavior, it's hard to wrap your head around why, when clearly it will cause them a lot of damage.
DeletePosted by Jamie Downer
It is also important to note that there are other insects like moths that show positive phototaxis and some insects like cockroaches that show negative phototaxis. Though the reason behind this behavior has not been analyzed yet, it seems to play an important role in food safety and preventing infections since many fly traps use different kinds of light to lure insects in.
ReplyDeletePosted by Veshal Venkat