Invasion of the Popillia Japonica


Just a quick rant about our friend popillia japonica otherwise known as the japanese beetle! It was introduced into the United States around 1916, on plants from Asia. It spread over 2,500 square miles in its first eight years in the U.S. Eggs are laid in the soil. The larvae that hatch, sometimes up to 1,500 grubs in one square yard of lawn, feed on the roots of grasses and plants. Using chewing mouth parts, adults typically feed on the leaves and flowers of a variety of plants, especially roses, but also grapes, berries, apples, hops, clover, soybeans, hollyhocks, elm and birch trees. They eat leaf tissues, between the veins, so a leaf that has been eaten by a Japanese beetle looks like lace.

We have tried just about everything at this point to rid our hops of these pests. Nothing seems to keep them away. The heavy rains of the last week kept them at bay for a while. This morning it's sunny and sure enough, they have returned. A quick shake of the vines and it started raining beetles. All were disposed of harshly. But I have no doubt that when I return this afternoon the reinforcements will have arrived. If anyone has a sure fire way to help get rid of these guys I would greatly appreciate it.

You can see the lace like leaves of our Willamette below. They do not bother the Cascades, Chinook, or N. Brewer nearly as much as the Willamette. We may end up sacrificing them in order to protect the other varieties.