The death of hundreds of innocent butterflies is nothing to feel good about. But there are just so many of them.
Molly Keck, an entomologist with the Bexar County office of Texas AgriLife Extension Service, blames the butterfly invasion on record September rainfall, which leads to the healthy growth of hackberry bushes.
"Their favorite food source — and their main food source — is hackberry,” she said. “And so when we have these pretty intense rains that hackberry starts to bud out … there is enough food for the babies and they live and they all become adults.”
Lots of adults.
Keck also said it just so happens to be nice weather to do a little flying.
"The cool weather on Saturday and Sunday and then hot weather Monday and Tuesday made us see this big bloom," she said.
Keck added even though we are killing them left and right with our vehicles, they intend us no harm.
"They're not going to hurt your plants or anything like that,” she said. “As adults, they are pollinators so just kind of enjoy them. After these guys go, we will probably see some monarchs come through.”
The extension service also reports the show is short because adult snout-nosed butterflies live just a couple of weeks.
So where are they going? Nowhere.
“They're kind of just flying around,” she said. “We call it a migration, but it's not a true migration. There's no direction or endpoint. They are just flying around, looking for a place to mate or a place to lay their eggs again."
She said this is one of the biggest blooms of the snout-nosed butterflies in recent years, but will likely end with any heavy rain that moves into the area this weekend.
She said big blooms usually are seen in September, and in the past has nicknamed them the “Labor Day butterfly.”
The National Weather Service reports there is a strong chance of showers Saturday and Sunday for the San Antonio area.
She said the butterflies are in heavy numbers in other areas of Texas right now where hackberry bushes are thriving.
Brian Kirkpatrick can be reached at firstname.lastname@example.org