Issue 13, August 8, 2016
Green June Beetle
Green June beetle adults are stocky, green, and about three-fourths inch long. They make a loud buzzing sound when they fly and apparently prefer to fly into upright objects, including people. They are most active on warm, sunny days and are present throughout Illinois. They used to not be present north of Peoria, but they were found this week in Oregon, IL in Ogle County. Green June beetle adults feed on flower pollen and are commonly found on flowers. They also feed on soft fruits, causing severe damage to ripening peaches.
Green June beetle adult.
Their larvae live on dead grass, being common in piles of grass clippings, piles of horse manure, and in turf. The larvae grow to about two inches long and appear similar to white grubs except that they are less likely to be C-shaped when found. They have an interesting habit of foraging above ground at night where they are sometimes spotted on sidewalks. They have shorter legs than other white grubs, so they flip over and crawl on their backs. They use long setae on their backs to grip the surface as they crawl.
Green June beetle larvae.
When feeding in turf, they tend to be present in higher numbers under trees. They leave one-half inch diameter holes in the soil when they come out of the soil to forage at night. Because they feed on dead grass blades, they do not do direct damage to turf but can loosen the roots as they feed. If treatment is needed, watering in an application of carbaryl (Sevin) or applying a white grub insecticide application will provide control.
Areas with green June beetle grubs commonly have large numbers of scoliid wasps whose larvae feed on them. Scoliid wasps are black and red with yellow spots on the abdomen. They are about one inch long and have bluish transparent wings. They are quite active during the day flying low over the turf. Although fearsome looking, they are reluctant stingers. (Phil Nixon)