Dragonfly Swarms in California: Why They're Everywhere and Why You Should Be Happy About It

If you’ve spent any time outdoors in California this summer, you’ve likely noticed swarms of dragonflies darting around parks, farms, and even city streets. It’s not your imagination. These aerial acrobats have appeared in extraordinary numbers this year, and experts say the warm monsoon rains we experienced in late spring and early summer created ideal breeding conditions for them. The result has been one of the most visible dragonfly seasons in recent memory.

Most of the dragonflies causing the buzz are called wandering gliders, a migratory species known for riding air pressure systems across long distances. Unlike other dragonflies that stay close to their home ponds, wandering gliders are travelers. They show up in large groups and move through an area over the course of a few days before moving on. For residents, the swarms can be an impressive sight. For farmers like Joe Del Bosque in Fresno County, they’re a welcome ally.“They are like little fighter jets,”he says.“They zoom in for other insects and capture them in the air.”

Dragonflies are among nature’s most effective predators. According to Chris Grinter, senior collection manager of entomology at the California Academy of Sciences,“They can eat hundreds of mosquitoes a single day.”That’s great news for gardeners, outdoor enthusiasts, and anyone tired of swatting bugs. Dragonflies spend most of their lives underwater as nymphs before emerging as flying adults, making their sudden appearance even more remarkable. Have you spotted any swarms near you? Let us know in the comments where you’ve seen the most dragonflies this summer.