Swarming insects have been appearing around the world in the form of vortexes, or "bugnadoes."
The bugnadoes may look menacing but aren't violent like tornadoes that may sweep across the United States or other parts of the world.
A bugnado was spotted by a photographer in early March in Portugal. The Portugal bugnado was comprised of red locusts but other bugnadoes have been swarms of midges, important decomposers in aquatic environments, much like earthworms in your garden, Executive Director Joe Keiper of the Virginia Museum of Natural History said.
Midges are also important fish, bird and amphibian food, Keiper said.
"Insects, such as these ‘midges,' swarm in their adult stages to find mates. Midges can be prolific and what we see in situations such as flooded farm fields that amazing numbers of larvae develop under the water," he said.
"Large amounts of nutrients support the temporary aquatic ecosystem and eventually, under warm temperatures and other desirable circumstances, these huge, synchronized emergences of short-lived adults occur."
Males and females seek each other out, he said.
The "tornado" appearance is likely due to a combination of wind and thermal uplift from the sun warming up the ground, AccuWeather.com Senior Meteorologist Bob Smerbeck said.
"I've been in a boat with fog on a lake at dawn when the sun comes out and starts to burn off the fog. The heating causes little vortexes all over the lake," Smerbeck said.
In addition to bugnadoes, dust devils and leaf devils have also been created by these vortexes, he said.
Proper conditions for a bugnado include an area to support gigantic populations such as a flooded farm field that has dead vegetation. The vegetation rots and generates nutrients for food sources that serve as food for the aquatic insect larvae, Keiper said.
In July 2011, storm chaser and photographer Mike Hollingshead was near Council Bluffs, Iowa, where he spotted a bugnado after flooding on the Missouri River.
Some insects are famous for huge swarms, Keiper said. The Great Lakes are known for midges and mayflies and the Chincoteague Wildlife Refuge for mosquitoes.
"These are just two specific examples where you have synchronized emergence of the adults and subsequent swarming for mate finding," Keiper said. "Other swarms, such as honey bees, occur for a different reason: to find a suitable nest site for the queen bee which has already been fertilized."
Bugnadoes may be dangerous to motorcycle riders who forget to keep their mouths shut, Keiper said.
"Seriously, clouds of insects like this can reduce visibility when they smash on a windshield, and have been reported that their dead carcasses can create slick conditions on roads. Slow down."
Insects can also show up on radar, as the National Weather Service in Albuquerque discovered last week. Unusual readings were noted three days in a row on the office's dual polarization radar.
Swarming grasshoppers were the culprit, the office determined.
The verdict is in: higher reflecivity values near the KABX radar the past 3 evenings are grasshoppers! #nmwx #abq pic.twitter.com/2KNY7KPmEj— NWS Albuquerque (@NWSAlbuquerque) May 30, 2014