SALT LAKE CITY — They are about one-quarter the size of a penny, spend 90% of their life in the dirt and are described as the most single important turf grass pest in the United States.
And they’re here in Utah, prompting the declaration of an “insect emergency infestation” this spring by the Utah Department of Agriculture and Food.
The invasive Japanese beetle is now the subject of a targeted trapping effort underway until mid-July by the agency, with trained insect trappers hitting neighborhoods along the Wasatch Front to determine the extent of their infestation.
“The whole idea is early detection and rapid response,” said Kristopher Watson, the state entomologist who oversees the agency’s insect and nursery program. “We want to find this when there is one beetle, not 1,000.”
The beetle feeds on more than 300 species of plants, including farmers’ crops, golf courses and park lawns, ornamental flowers in neighborhoods and landscape nursery inventory. They can cause millions of dollars in damage to the agricultural industry if they get established.
Oregon, which is battling an infestation of some 25,000 beetles, estimates it will cost its agricultural industry $43 million a year if bugs aren’t wiped out.
Utah has been there and done that, and in fact battled the beetle in a yearslong trapping program in Orem that began in 2006.
An estimated 2,600 beetles were caught in an effort that Watson said that, to date, is the most successful eradication in the country.
“I hope no one has to beat that,” he said, while acknowledging Oregon’s fight and its key role as a supplier of nursery stock in the region.
The agency, using nine trappers, will set up a little more than 3,000 traps in a targeted grid system, mostly concentrated along the Wasatch Front in a variety of settings.
“Eighty percent of the traps will be put along the Wasatch Front because that is where 80% of the population lives and where there is 80% of the problem. These pests don’t move around on their own. They move where people do.”
The pest was first discovered in the United States in 1916 and is suspected to have arrived in the country via a potted plant from Japan, their native country.
The Japanese beetle is an opportunistic traveler and can invade states via a number of means, including airplane cargo. In Oregon, Portland International Airport is a hot spot for the pests.
Utah is only one of 12 states that are considered noninfested by the beetle and takes an aggressive posture when it comes to quarantining nursery and other products from outside its borders.
“In most states, they just give up on it,” Watson said. “In Utah, we don’t want it to come, but it doesn’t do you any good if your neighbors are not taking care of it.”
In fact, Watson said there are 30 other states that do not have an active monitoring program in place.
This year’s trapping effort, which will include all 29 counties, was ramped up in response to the 2019 capture of 43 beetles in six different locations: four in Salt Lake County and two in Davis County.
“In Davis County, there were just a few beetles so we want to see if there is something established. We want to know the extent of the population,” Watson said. “We need to know something about it before just going in and spraying.”
The capture of beetles will trigger application of a pesticide to wipe them out.
Traps are being set in both trees and a few feet above turf in areas where there is good sunlight.
Insect trapper Sharon Gilbert set out traps Thursday on property in Rose Canyon in Salt Lake County owned by Kathy Fuller and her husband, Gary.
“They were out here two years ago and did something similar,” Kathy Fuller said. “I am supportive of this, of keeping track of what is native and if there are problems with stuff being imported accidentally. It can affect people with crops and our native species of plants.”
Fuller said she does battles of own with another invasive species, the thistle plant.
“That is imported and takes over everything. If you let it go, it takes over the whole hillside.”
All the traps will be set by mid-July and then collected in the fall to see if any Japanese beetles have been captured.
“An ounce of prevention is worth of ton of cure,” Watson emphasized.