The leaves on your trees not looking as lush as they should?
Japanese beetles have been spotted in the Twin Cities, including Woodbury.
"They will feed on the leaves... they feed between the veins, a kind of feeding called 'skeletonizing.' They also feed on flower blossoms," University of Minnesota Entomologist Jeffrey Hahn told KARE 11. "They start coming out, basically, the first week of July. So, think of the Fourth of July when Japanese beetles will come out and then they are active for the rest of the summer. I mean, we will see them into September."
Last summer, Woodbury resident Lisa Thor, who lives in the city’s Highland Heights neighborhood, said she .
“I think I was finally able to get my annuals out about mid-June, and the beetles flocked to them immediately,” Thor said then. “I just noticed the beetles on my birch tree about three weeks ago.”
Hahn that the beetles since 2001 have been concentrated in Hennepin and Washington counties.
“The Japanese beetles like to feed on over 300 types of vegetation, so it’s really hard to say why these beetles favor these counties,” said Hahn. “Beetles do attract other beetles, so once they find food sources, you can bet on others showing up.”
The beetles are pests “because the adults feed on the leaves and flowers of many plants while the grubs feed on the roots of turf grass,” he wrote “If you have seen JB grub damage in the past, July is a good time to treat your yard. Use a preventative insecticide, like imidacloprid, after you see adults flying, about late June or early July this year. By the time eggs are laid and grubs hatch, about two to three weeks, the insecticide will be taken up by the grass and the young grubs will be exposed to it.”
If you’re looking to get rid of them, one thing seems clear—do not use traps.
“Research does not support these types of traps and it actually attracts more beetles to an area, so you are doing more harm than good,” Hahn said. “As far as trees go, assess where the trees are in your landscaping and if the trees are an important focal point of your yard, I’d get them sprayed."
For more information check out a University of Minnesota Extension page about Japanese beetles.