Japanese beetle season is once again upon us. Green June beetle season is once again upon us. These have become annual events and I’ll just tell you up front, they’re not going to go away and the numbers of the little marauders will likely increase in the years to come!
Japanese beetles are small greenish beetles (scarab beetles to be precise) much like our typical June “bugs”. They are a rather attractive metallic green with coppery colored wing covers and a series of white dots along the back half of their abdomen that show up just under the wing covers. They are almost one half inch long so they aren’t big. Don’t confuse these with the much larger green June beetles that just started showing up in the past ten days. The green June beetle is nearly an inch long and has a dull velvety green and tan coloration. Green June beetles are a native species, Japanese beetles are not!
There are other differences between the two species. Japanese beetles are foliage feeders and are especially fond of roses, grape, crabapple, Virginia creeper and linden trees. They are also very gregarious often feeding by the dozens on the same plant. When disturbed they just fold in their legs and drop to the ground. You simply don’t seem them flying all that often.
Green June beetles are frequently seen flying simply because they don’t fly well and often run into anything in their way. Many people also mistake them for some kind of bee or wasp because they fly low and very noisily. Green June beetles feed on ripening fruits and they aren’t picky. Anything from blackberries to peaches or pears and apples. In southern states they used to call them fig eaters! Once they get into ripening fruit all their friends join them and can really mess up fruit in a hurry. The front of the peach looks fine but you grab it and a dozen big green June beetles come tumbling out the back.
There are several insecticides that are effective against both of these insect pests. It’s often best to spray first thing in the morning when they are most active. Japanese beetles tend to have a fairly short period when they are active but they can do a lot of damage in just a few weeks. Since we are most often treating ornamental plants for Japanese beetles we have more insecticide options. Any of the pyrethroid products are effective and will last two to three weeks. Feeding damage is often observed for just four to six weeks
Green June beetles, since they are usually feeding on fruit, have a much more limited selection of insecticides that we can use. Carbaryl, malathion, and acetamiprid are all effective against June beetles. Check the label to make sure that your insecticide product is labeled for the fruit species you are spraying it on. Green June beetles will likely be around for a month or more but tend to have peak activity about right now.
Japanese beetles, due to their propensity of falling when disturbed and for being rather sluggish first thing in the morning can be readily dealt with in a very natural control method. Get a bucket of soapy water and a small paint brush and go around every morning and flick the beetles into the bucket where they will drown in the soapy water. While there are also Japanese beetle traps available I discourage homeowners using them. The scent lures that come with these are VERY effective at attracting beetles to the area of the trap. Unfortunately, more beetles are attracted than wind up in the trap and you can wind up with more beetles in your yard than you would have had otherwise! Yes, both beetles are a nuisance and sadly they are here to stay!