Grasshopper swarms are gone, but likely to return in few years

The Las Vegas Valley viral grasshopper swarm came and went like a passing internet fad.

Appearing in the valley in mid-July, the influx of grasshoppers briefly captured the attention of the city and the nation, spawning viral videos, coverage from major news organizations and short-lived grasshopper pizzas and drink specials. But summer continued and the bugs quietly disappeared.

“That’s kind of what we figured would happen is after a week, week and a half, they’d move on or die off,” Jeff Knight, the state entomologist for the Nevada Department of Agriculture, said Wednesday.

The influx was caused by an unseasonably wet winter and spring, which caused the insects to travel from northern Arizona and Laughlin, flying as far north as central Nevada, the department said during a July 25 news conference.

The swarm wasn’t a new phenomenon, as the grasshoppers have migrated into the valley a handful of times in the past 50 years, Knight said in July.

The migration had to end eventually.

“There might be a few stragglers around,” Knight said Wednesday. “They might have moved further on out into the desert; there’s no way to tell exactly where they went.”

It will be hard to predict when the next grasshopper swarm may arrive in Las Vegas, he said. It will depend on weather conditions in the months leading up to the migration.

“The populations can build up, and have done in the past and probably will in the future again,” Knight said. “It’s a naturally occurring thing. It’s nothing that we’re going to be able to do (anything) about, or predict.”

National Weather Service meteorologist Caleb Steele said it’s not unusual for the valley to get a rainy season once in a while.

“Anecdotally, it seems every three to four years we have a wet year —a wetter year,” Steele said, adding that’s the approximate amount of time between seasons with about 3 inches of rainfall.

As of Wednesday, the valley has seen 4.64 inches of rain, which is measured in the central valley at McCarran International Airport.

Before the arrival of grasshoppers, the valley saw the wettest May in more than three decades, the weather service had said. The valley passed the normal annual rainfall for the entire year —4.19 inches — during that month.

It may be another half-decade before Las Vegas sees another grasshopper infestation, as rainfall totals of more than 4 inches seem to happen about every five years, Steele said.

Grasshoppers don’t carry diseases or bite. Knight said Wednesday that he hadn’t heard of any major plant damage or any safety issues caused by the infestation. The most trouble they seemed to cause was a brief annoyance.

“All I’ve heard is exactly that —that they were a nuisance,” Knight said.

He said one of the more exciting aspects of the grasshopper migration was the attention it drew to Southern Nevada.

“It went pretty worldwide,” Knight said. “I got reports from friends in Italy, and we got calls from reporters in India. That made it interesting.”

Contact Katelyn Newberg at knewberg@reviewjournal.com or 702-383-0240. Follow @k_newberg on Twitter.