They’re big. They’re pesky. And this year, they’re everywhere.
At least in some Texas backyards, this spring seems to be a big year for crane flies, or mosquito hawks, or skeeter eaters, or gollywhoppers, or whatever it is you call them.
It seems like every time I open the door to my home in Arlington these days, four or five fly inside. They’ve given my house cat plenty of entertainment, but they sure can be annoying when all the other lights in the house are off and they flock to my bedside reading lamp at night. And don’t get me started on an unfortunate recent incident of an open water bottle turned fly trap that I grabbed to drink without properly inspecting.
You know it’s springtime in Texas when the huge, harmless, mosquitoesque flies are drawn toward porch lights and start to sneak their way inside. Seeing crane flies means warmer days are most certainly ahead.
“They’re Texas groundhogs,” says Molly Keck, an entomologist with Texas A&M AgriLife Extension Service in Bexar County. “It’s the turn of the season.”
Keck says it may not be a record year for the bugs everywhere. The key to a lot of crane flies’ fortunes in the spring is last fall’s weather. A wet fall, combined with a mild winter and a slow warming up to spring, means more crane fly eggs and larvae are likely to survive to maturity. If it’s a particularly dry year, those eggs may not survive or may remain dormant to wait for a more favorable season.
Conditions were perfect over the last few months, at least in North and Central Texas. “Some places got rain at the right time that allowed the spring emergence,” Keck says.
Crane flies aren’t a species but a family, Tipulidae, which consists of more than 15,000 species worldwide. Like butterflies, crane flies have a multistage life cycle. It starts when adults—the big flies that swarm porch lights—lay eggs in the soil. If the soil stays moist and in the right temperature range, the eggs will hatch as grublike larvae. Those larvae spend months munching on grass roots (a habit that can sometimes cause problems for lawn health) and growing. They then enter pupal cases, similar to butterfly chrysalises, where they transform into the adult crane flies that are most often seen.
Crane flies are nocturnal and are attracted to lights at nighttime. That’s why so many end up on your porch—and eventually end up inside. The flies also spend time resting in tall, dewy grass, where they lay eggs.
The spindly-legged insects look a lot like their bloodsucking mosquito cousins, but they’re harmless. They resemble giant mosquitoes, which has given them the “skeeter eater” moniker, but they don’t share many traits with the pests. They don’t bite or sting humans, and they aren’t pests in the way other insects can be.
And despite their colloquial nicknames, adult crane flies don’t eat mosquitos, either. In fact, they don’t eat much at all.
“They don’t even have functioning mouth parts as an adult,” Keck says. “They do most of their eating in the larval form.”
Instead, the adults are mainly focused on one task: mating. Keck says they don’t have a very long lifespan after emerging as adults, mating, and laying eggs in the soil. “Minus cats or kids who want to smash them,” Keck says, they’ll live only about two weeks.
Because they’re harmless to humans, Keck says there’s not much people can—or need to—do to get rid of them. Keeping doors closed and outdoor lights off at night helps, but she said it’s easy enough to swat them away.
“You’re in Texas,” Keck says, “and this is what we have.”