A total solar eclipse will darken the skies in parts of the United States on April 8, but people won’t be the only ones awed by the celestial event. Totality during solar eclipses also affects the behavior of insects, from fireflies to crickets, and prompts them to go into their nighttime routine – a phenomenon only seen during total solar eclipses.
We spoke with University of Florida Institute of Food and Agricultural Sciences entomology Professor Marc Branham to explore why insects have such a unique reaction to total solar eclipses and how these observations can expand our understanding of these behaviors.
How do insects typically react when there’s a total solar eclipse?
There’s not a lot of actual published information on these changes. It’s because I think there haven’t been people in these events who are looking down, everybody is looking up at the actual eclipse, and it’s remarkable how little has been reported about the resulting animal behavior.
For all the biologists that are out there and all the organisms that are in nature, there’s a surprisingly small amount of information on the effects on animal behavior during totality. Most people are so focused on the solar eclipse than what is happening around them.
What have you observed during totality?
When you experience these events, it’s the strangest feeling, because it gets really dark, really fast, and you experience other environmental conditions, like it gets cooler in a very short period of time. When that totality hits, all the birds stop singing, field crickets and tree crickets that are singing, they just stop, and it’s really surreal. That’s when I started seeing fireflies flash.
What insects react differently?
There are several published observations of honeybees stopping foraging. They will stop leaving their hives in these totality events and start behavior that’s consistent with shutting down for the night. They will stop foraging, or they will not head out on their foraging flight. Also, crickets chirping is pretty common.
What can we learn about insects during the total solar eclipse?
I think it can tell us a lot about how insects sense their environment and what are the environmental triggers that initiate certain kinds of behavior.
They can decrease competition with other species that are active at certain times of the day by knowing when to be active and when to go to sleep. The clock for waking and sleeping can be internal or it can be based on the amount of light in the environment.
Eclipses are remarkable events for a variety of reasons, and we can learn a lot about our natural environment by how animals and insects actually change their behavior when the lights go out at an unusual time.
I think fireflies are a great example of that because they’re so obvious when they flash and to see them flashing when they shouldn’t be in the middle of the day is not only very obvious, but it’s probably unexpected for most people. It’s a pretty rare event as far as fireflies go.
