They're creepy, crawly and hungry. They are the Japanese beetles, and they are invading yards all over the metro. The bad news is, if Japanese beetles are invading your trees and plants there's not much you can do it about it right now.
NU extension entomologist Jonathan Larson says insecticides can only be applied to adult trees in the spring. "You wanna treat things like trees in April or May with a systemic insecticide. They'll get up into the leaves and protect them at this point in the summer."
There are insecticides to help, and Larson says some are organic. "Neem and pyola, and they help to control the Japanese beetle on the leaf by paralyzing the beetle."
The metallic pests love to feast on things like Birch, Linden and various tree fruit as well as roses, grape vines, soybeans and raspberries. The Japanese beetles can strip a free of it's foliage, but they cannot kill the tree.
Although there is no guaranteed way of getting rid of the Japanese beetle, if you do find yourself battling the pests, you can try a few of these tips.
Hand Pick: The most effective way of getting rid of Japanese beetles. Pick them off, put them in a solution of 1 tablespoon of liquid dish washing detergent and water, causing them to drown.
Neem Oil: The adults ingest a chemical in the neem oil and pass it on in their eggs, and the resulting larvae die before becoming adults. Should be reapplied after rainstorms.
Insecticides: Apply sprays in the morning, never in full sun or at temperatures above 90º F. If plants start to wilt, rinse the leaves with clean water.
Traps: Japanese beetle traps are available for purchase, but know that the traps do not effectively suppress adults and might even result in a higher localized population. For best results only use them in a very large yard and place traps far away from plants so that the beetles do not land on your plants on their way to the traps.