Green beetles and their grubs are responsible for significant damage to pastures and orchards in the southeastern portion of the United States, from Texas and Nebraska to the mid-Atlantic states. The beetles are capable of causing severe damage to orchards as they feast on fruit, especially stone fruits. The grubs on the other hand are ground dwellers and feed primarily on grasses, sometimes doing extensive damage not only to pastures but to lawns as well. In some areas, an orchard located next to a pasture is almost guaranteed to have problems with green beetles.
Up to a point, green beetles can be considered to be beneficial, since when they burrow in the soil to lay their eggs, they enrich and aerate the soil. Unfortunately, this good is often undone by the damage the grubs do in fields of grain, or the adult green beetles do to apples, pears, peaches, and even grapes.
Although green beetles have a preference for fruit that is somewhat decayed, they will attack fresh fruit as well, and it is their droppings that foul the fruit that actually causes the bulk of the damage. Green beetle droppings resemble mouse droppings and are therefore somewhat larger than one would usually expect in insect droppings.
See Related: House Beetles
Come On Over
Feeding on fresh fruit rewards the green beetle by increasing its longevity and also increasing its egg laying capacity. One a beetle has located a source of sweet food, the fruit, it emits a special odor that alerts other beetles and tells them to “come on over”. A few beetles, congregating on a peach or apple, can devour large chucks of the fruit in a relatively short time. If the fruit tree or orchard is near a pasture where grubs have hatched, there will be a steady succession of green beetles coming to feed on the fruit. Most of the damage is done in late spring or early summer, particularly the months of June and July, giving the beetle the name Green June Beetle in some areas.
Green Beetle Control
The application of insecticides is the best defense against green beetles, but the application has to be somewhat intricately timed to the hatching periods. One strategy that some orchard owners use is to place trays of fermented fruit, laced with insecticide, around the perimeter of an orchard. As the beetles have a natural preference for fermented fruit, this strategy is most often effective. Again, timing is important. A steady application of insecticides or continual use of insecticide-laced fermented fruit, while effective against green beetles, could in some instances prove devastating to non-target and more beneficial insects.
Beetle And Grub Description
The beetles are not unattractive, being a velvety green color with orange stripes along the edges of their wings. Approaching an inch in size, green beetles are fairly large insects. After hatching, they fly around pasture land in zigzag maneuvers seeking mates, a process which lasts for days with newly hatched beetles emerging from the ground in waves. Walking though a pasture, one could find himself or herself amidst a swarm of these beetles flying waist-high in all directions. The female will burrow into the soil to lay her eggs, up to 100 of them. The green beetle grubs have six legs, which they don’t always use, as they have the strange habit of crawling on their backs. The grubs are white and are typically about 2 inches long. Grubs feed mostly during the night, burrowing into the soil during the day. Because of their burrowing habits and the fact they can be present over large areas, they can be difficult to control, more so than is the case with the adult beetles.