The beetles are back and unfortunately I am not talking about Paul, Ringo, George and John. Based on the customers we have had in the Garden Center so far it seems we have a bumper batch of the pesky bugs this year. Japanese beetles can be very destructive and are not very selective in what they eat. The beetles start as a white grub and the adult beetles typically come out in late June and hang around through August. During that time they eat, mate, and lay eggs for next summer’s beetles in your lawn.
What do they do? When in feeding stage the grubs eat the roots of lawn grass and can reduce the root system enough that grass can die in the summer heat and dry winds. The adult beetles chew on plant leaves leaving them with a lacy or skeletonized look. Their favorite plants include grape vines, crabapples, hollyhock, roses, plum, apples, lindens, and birch to name a few.
What can you do? There is no easy guaranteed solution for dealing with these pests. There are a variety of sprays, lawn treatments and traps. Japanese beetles can fly for miles making treatment a challenge. Treating the lawn to kill the grubs hardly puts a dent in the number of beetles able to visit your yard so it isn’t recommended unless you are experiencing lawn damage. Grubs can be treated with a granular treatment, Bonide Grub Beater, which can eliminate grubs and the lawn damage they cause. As for the adult beetles you can physically remove them from plants and toss them in soapy water.
If you are looking for a chemical approach, a spray like Bonide’s Captain Jacks Dead Bug, Japanese Beetle Killer, or Eight can be used. These sprays can also damage beneficial insects like bees so be sure to read and follow all directions on the label and don’t spray where bees are feeding. Traps can also be used to attract beetles. Many go into the traps, but some may still find their way onto desirable plants so be sure to hang traps away from the plants you are trying to protect. And boy do they bring in the beetles!