How Big Can an Insect Swarm Get?

Earth’s recent weather patterns have produced some very unusual events, from record-breaking floods and devastating tornadoes to extreme fluctuations of temperature. You can also add insect swarms to the list. For example, in 2011, the Midwest experienced massive swirling vortexes of insects sweeping across flooded cornfields, a phenomenon someone called a “bugnado.” But these aren’t destructive swarms, only harmless midges engaged in a mating frenzy. The midges form large, conical swarms when they’re in the mood to mate, which is typical of many insects. Flooding turns an area into the perfect spot for midges to reproduce.

Attack of the midges:

• Male midges fertilize a female, and then die. The female seeks a body of water where she can deposit the eggs. A flooded cornfield, in this case, supplies abundant food for aquatic insect larvae.
• The only real threat that midges present is to motorists, as large numbers of dead midges can cause road surfaces to become slippery.
• Midges are an important source of food for fish, birds, and amphibians, says entomologist Joe Keiper of the Virginia Museum of Natural History.