Ask the entomologist: What are those swarms of flying insects following a rainstorm?

Chances are the flying insects are desert termites, also known as agricultural termites

Desert termites swarm after a recent rainstorm in the San Antonio area. (KSAT)

SAN ANTONIO – After Sunday’s rainstorms, some residents in Northeast Bexar County and Guadalupe County reported seeing swarms of flying insects.

Okay, I was one of them. I noticed swarms of insects all across my neighborhood and then noticed others asking about them on social media as well.

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So I asked an expert for the answer.

Molly Keck is an entomologist with the Texas A&M AgriLife Extension Service in Bexar County.

She says the insects are desert termites.

Don’t worry, desert termites, also known as agricultural termites, aren’t the kind that eat up your home.

“They do not cause damage to plants or structures. They feed on dead and stressed forbes, grasses, and roots,” Keck said. “Sometimes cause some damage to turf, but usually because the grass isn’t well watered and the roots are too short as a result of shallow watering.”

Desert termites swarm after a recent rainstorm in the San Antonio area. (KSAT)

Desert termites are native to our area.

The fact that there were so many of them this past weekend was a combination of the right weather conditions and the insects’ biology.

“They sometimes just decide to swarm in large numbers,” Keck said.

The reproductive forms of desert termites fly out of their colonies to mate in the spring and summer months when it’s hot and very humid.

The winged versions are called swarmers or alates. They leave the colony to find locations for new colonies.

They may not cause any damage, but large swarms can leave behind a mess of discarded wings.

Desert termites swarm after a recent rainstorm in the San Antonio area. (KSAT)

If you have desert termites, there’s no need to call out pest control. If you keep your grass well-watered, they won’t cause any harm, and they’re actually good for the ecosystem.

“Desert termites help regulate the flow of carbon and nitrogen in an ecosystem. They process as much as half the dead roots and litter in annual and perennial grasslands,” according to the AgriLife Extension website.

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About the Author

Julie Moreno has worked in local television news for more than 25 years. She came to KSAT as a news producer in 2000. After producing thousands of newscasts, she transitioned to the digital team in 2015. She writes on a wide variety of topics from breaking news to trending stories and manages KSAT’s daily digital content strategy.

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