A worrisome detail there: The beetles eat flowers of milkweed (Asclepias), biting into their nectaries and draining them. The plants then fail to set seed — yet another potential threat to the shrinking milkweed populations, which, in turn, threatens the monarch butterfly.
And onward the beetles march. The Sacramento area is now trying to eradicate them before they become established, as are locations in the Pacific Northwest, including Portland, Ore., and British Columbia.
Europe is also under pressure. This most recent fight will be especially challenging, Dr. Potter said, in the same way that it is in the United States for organic grape or blackberry growers. Europe does not have a chemical lawn-care industry like we do, and chemical pesticides are often the go-to for tackling grub infestations here. Overall, European restrictions on synthetic insecticides are far more stringent.
“It is a major concern — imagine what it would do in French vineyards,” Dr. Potter said. “They can’t spray their way out of this problem.”
They Also Like Orgies
Ninety percent of insect species are specialists, focusing their diets on no more than two or three plant families, Dr. Potter said. Not this one.
The Japanese beetle is not just a generalist, but “an extreme one,” he said. “Even gypsy moths don’t feed on as many plants as the Japanese beetle. It’s probably the champion insect in North America — remarkable for a nonnative.”
Originally Appeared Here