A couple of aggressively feeding insects have been very prevalent across the district over the last couple of weeks. Often mistaken for one another, Green June Beetles and Japanese Beetles have made their presence known in a big way this summer.
Green June Beetle adults really like ripening fruit, often focusing their feeding efforts on apricots, peaches, apples, pears and blackberries. Similar to what we often call the June Bug, they have a dull, velvety green and tan-colored back with an iridescent green underside. Their navigational skills aren’t great, so as they are looking for a mate, they seem to buzz about haphazardly until they hit something. Unfortunately, that something is often a person who thinks they are being attacked. Fortunately, they’re harmless to humans.
Japanese Beetles feed on more than 300 species of plants including many deciduous species, fruit trees and even garden plants. Adults are approximately seven sixteenths of an inch long (about two thirds the length of the Green June Beetle) and metallic green with coppery wing covers. One identifying characteristic is the series of white dots made up of tufts of hair that project from under the edges of the wing covers on their backs. They tend to form in groups at the top of plants, dropping to the ground when disturbed.
Both will definitely catch your attention, particularly when they start to do damage to landscape or garden/fruit species. The group feeding nature of Japanese beetles allows them to be controlled with many common pyrethroid, carbaryl or Neem containing insecticides. Adult beetles can also be killed by shaking the beetles from the plant into a jar or bucket containing soapy water. This is best done in the morning when the insects are sluggish.
Because Green June Beetles are doing quite a bit more flying than the Japanese beetles, control of them is a little more difficult. Several insecticides are labeled for application to fruit crops that can be ingested as the insect is feeding. Neem products may be used as a repellent.
Good coverage is essential for insecticide applications. Always read and follow label directions when applying any pesticide products. Most all products have some level of pre-harvest interval or PHI. That PHI is what you need to be aware of so that you are allowing an appropriate number of days between application of the product and harvest of the desired produce. PHI’s may differ between products, and even by the species they are being used to control.
David Hallauer45 Posts
David Hallauer is the Meadowlark Extension District agent in the areas of horticulture and crops and soils.