STAUNTON, Va. – Last week, meteorologists in Ohio spotted something unexpected on the radar – a swarm of migrating dragonflies. Dragonfly swarms have been reported in Virginia and other nearby states. On Sept. 10, the National Weather Service of Cleveland tweeted about the new development.
It is common for dragonflies, especially green darner dragonflies, to migrate south in the fall to find warmer weather, but the swarms are unusual.
While we are not biological experts, we have determined (through input from our followers) that it's most likely dragonflies mixed with other insects/birds! https://t.co/5MeJXj37zq— NWS Cleveland (@NWSCLE) September 10, 2019
Ohio State University entomology professor Norman Johnson told CNN that although weather conditions can cause the traveling insects to swarm, it is not a regular occurrence.
In 2018, The Washington Post reported that the migration of green darner is typically inconspicuous because the bugs rarely travel in packs.
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These dragonflies are very sensitive to temperature. "Climate warming could really disrupt the presence of this migration," Colin Studds, an animal ecologist at the University of Maryland-Baltimore County, told the Post.
It is fairly common for radars to pick up biological movement, especially around sunrise and sunset when warmer air can bend the radar beam toward lower elevations where the movement occurs, according to meteorologist Chris Michaels.
People reported dragonfly sightings on social media.
The dragonflies are largely harmless, especially compared with the annoying mayfly swarms that took over Ohio in June.
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This article originally appeared on Staunton News Leader: Swarms of dragonflies are so big they can be seen from space