Ladies and gentlemen, the beetles!
No, that's not a back-in-the-day introduction from “The Ed Sullivan Show,” but a warning from an expert that Japanese beetles are eating up plants in parts of Iowa and Nebraska, including the Omaha area.
The insects are not native to the United States, said Kathleen Cue, an extension associate for horticulture at the University of Nebraska-Lincoln Extension in Douglas and Sarpy Counties. They started working their way west from the East Coast, probably about 20 years ago.
“They were accidentally brought in by nursery stock,'' she said.
Japanese beetles will munch about anything.
“The adults are voracious eaters,” Cue said. “They'll eat a huge array of plants.”
The beetles may be proliferating because of the mild winter and early spring in the Omaha area.
“Obviously, they liked our winter,” Cue said.
The females can produce multiple broods throughout the growing season, she said, and their juvenile stage, as a grub, is harmful to turf grasses.
Cue said her office has received numerous reports from homeowners about the beetles, which measure one-quarter of an inch wide and three-eighths of an inch long. They are an iridescent brown-green with tufts of white hair on their sides.
Nine counties in Nebraska have confirmed infestations: Douglas, Sarpy, Lancaster, Washington, Saline, Saunders, Dodge, Hamilton and Dakota.
Laura Jesse, an extension entomologist with Iowa State University Extension, said Iowa has had its fair share of the bugs.
“So far this summer, they've been bad in certain areas,” she said, listing Cedar Rapids, Iowa City, Ames, Des Moines, Sioux City and several western counties, including Pottawattamie, Fremont, Harrison and Mills.
She said the beetles were first spotted in Iowa in 1994.
Homeowners can apply an insecticide or use a pheromone trap, which is a sex attractant, Cue said. She urged placing the traps in an empty lot, not in a yard, because the traps can draw large numbers of the bugs.
Donald Lewis, a professor and entomologist at Iowa State, said 57 counties in Iowa have been infested. He said for the best results, a systemic insecticide should be applied next spring, three or four weeks before the bugs appear.
The insects were two weeks or so early in their initial emergence this spring, Lewis said, and their populations exploded during the high temperatures earlier in the month.
Generally, the beetles don't kill well-established plants, but they can damage them. Jesse said homeowners should keep an eye on newly planted trees.
“We try to remind people that the damage is mostly cosmetic,” she said. “It looks a lot worse than it is.”
Another insect, the Basswood Leaf Miner, is also leaving a trail of damage in the area. The adults and larvae are hitting linden trees hard, Cue said.
“We don't know why,” she said. “There's not a lot of research on them.”
The eggs are laid in the linden's leaves, Cue said, and the adults then feed on the leaves.
“They leave the leaves looking like window panes,” she said.
A linden's leaves can be sprayed, Cue said, or a root feeder can be used, although it takes about a month for a root application to reach the tree's top.
Another fallout from the early spring: It may allow the leaf miner to produce two generations during the growing season, she said.
Cue also warned homeowners that the Emerald Ash Borer continues to work its way toward western Iowa and Nebraska.
The insect is transported mainly in firewood. It, too, is migrating from the East Coast. It eventually could decimate ash trees that are popular among homeowners.
Cue said the borer has been reported in northeast Iowa, Minnesota, St. Louis and south of Chicago.
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