‘Disgusting' larvae infestation in home led to beetle discovery near Boise

Yahoo

10-05-2025

Armando Falcon-Brindis was busy with work at the University of Idaho's Parma Research and Extension Center last summer when a request came in from an Eagle homeowner to identify the dozens of larvae infesting her home.
From photos the homeowner sent, the pests looked to be wireworms, larvae of a family of beetles common in Idaho. Falcon-Brindis, an entomologist, was ready to reply to the woman and leave the conversation at that. But the sheer volume of larvae in her photos made him reconsider.
He asked the homeowner to send samples of the larvae, which he looked at under a microscope. It was difficult to tell exactly what the insects were, as they resembled other beetle larvae — but they were not wireworms. So Falcon-Brindis visited the woman's home in Eagle to track down the adult beetles. Their morphology would be more distinct and allow the insect expert to hone in on which species was infesting the home.
He found the small, black beetles, and that's when he realized something exciting — for scientists, at least.
Falcon-Brindis identified an invasive insect species that's showing up in Boise-area homes and could become a 'disgusting' nuisance for more residents this summer dealing with large numbers of larvae and resulting adult beetles. It's the first time the beetle has ever been documented in Idaho.
'It was all kind of accidental,' Falcon-Brindis, an assistant professor, told the Idaho Statesman in a phone interview. 'That's the way science occurs sometimes.'
The species he identified — Opatroides punctulatus Brullé — is part of a family of darkling beetles that contains about 20,000 ground-dwelling beetle species, according to a University of Idaho news release about Falcon-Brindis' discovery. That family includes the beetle species whose larvae, called mealworms, are commonly sold as feed for pet reptiles and birds.
'It's exciting from a scientific perspective because that means you're doing something for society and finding something that could be a potential issue,' Falcon-Brindis said. 'You're documenting the insects and hopefully somebody else could use this information.'
The beetle Falcon-Brindis identified is considered invasive in the United States. It's native to the Mediterranean, which has similar temperatures and weather patterns to the Treasure Valley.
According to the U of I news release, the beetles were first confirmed in the United States in California in 2009, and later in Nevada in 2015.
In January, Falcon-Brindis and two of his colleagues, master's student Henry Trujillo and Minidoka County U of I Extension educator Jason Thomas, published an academic article on the Idaho discovery. Their research included investigating an infestation at another home in Emmett.
The news release said the researchers found the larvae were far more prevalent in places where soil was extremely dry and a lot of organic matter was present. Large amounts of larvae were in dark crevices inside the homes, including under appliances or furniture.
Falcon-Brindis said in a way, wireworms could have been a worse infestation for the homeowners. That family of beetles is particularly damaging to crops like potatoes and cereal grains.
The entomologist said the invasive beetle species he documented likely won't mean trouble for Idaho's agricultural industry, but it could cost homeowners time, money and frustration.
'They're not eating the carpets or wires or anything,' Falcon-Brindis said. 'It's just annoying and, of course, disgusting for people to be dealing with that.'
He said it can also be expensive. The U of I news release noted the Eagle homeowner would 'sweep for larvae four or more times per day, yet they'd return as fast as she could clean.' The infestation didn't seem to respond to pest control, either.
'She said she had already spent over $200 in pest control and cleaning to try to figure out what this was,' Falcon-Brindis said.
'The very first step for pest control is to identify the organism properly,' he added. 'If you don't know what you're looking at, there's no management applicable there. You don't know where you're going.'
Falcon-Brindis said he hopes to do more research on the species, particularly on how climate change and its impacts on temperature and precipitation will impact the life cycle of the beetle. He said anyone who believes they may have an Opatroides punctulatus Brullé can reach out to the U of I Parma Extension's entomology department.
The researcher said Boise-area residents can expect to see the invasive beetle and its larvae in mid- to late summer and early fall.
'They're trying to enter homes for pupating and resting and overwintering,' he said.
Because research showed larvae seemed drawn to dry soil, he suggested homeowners create a barrier of well-watered soil around their homes to keep the larvae at bay.
Conor Follette, president of Habitat Pest and Lawn in Boise, told the Statesman his company frequently deals with different types of darkling beetles. He said Habitat addressed an infestation at a commercial office complex last fall that may have been Opatroides punctulatus Brullé.
'My first initial reaction was that they were mealworm larvae but they seemed to be occupying mostly outside planters and decaying organic material,' Follette said. 'So eventually I determined that it's another type of darkling beetle, which one specially I was unsure of.'
Follette said the invasive beetle's diet includes decaying organic material and recommended keeping yards free of dead grass and debris to reduce the possibility of infestation.