Field Guide     Pest Management     June Bug

June Bug

CROPS IMPACTED: Turf, sweet potatoes, carrots, and ripe fruit.

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Family: Scarabaeidae

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About June Bugs

Reproduction and Life Cycle

Annually, June bugs complete one generation. After mating, females dig into moist turf to lay a compact cluster the size of a walnut of 10 to 30 eggs. Once the eggs are laid it takes about 10 to 15 days for them to hatch. The grub/larvae that come from these eggs are nocturnal feeders, eating only organic matter. During this period, June bug larvae go through 3 molting stages. At this point cold fall temperatures have arrived; the third stage larva digs deep into the soil to overwinter. They feed and finish maturing in the spring, emerging in late May to mid-June and mate. The female beetles lay their eggs in late summer and the process continues.

June Bugs Identification and Habitat

Identification

Fully mature June bugs are about ¾ to 1 inch long. The upper surface of the adult body is silky green to dull brown with green stripes running lengthwise and yellow to orange margins on the hard, front wings. The underside of a June bugs body is shiny metallic gold or green and has a small, flat horn on their head. The eggs produced by females are round, about 1.5mm in diameter and absorbs the moisture in the soil. The grub or larva of the June bug is initially about 3/8 inches and over the molting process grows to about 1 ½ inches long. They have stubby white bodies with the upper surface covered with short, stiff hairs that help them move and very short legs. June bug larvae crawl on their backs rather than having to use their small legs.

Habitat

June bugs burrow below the soil line at night to be able to feed on the turf. Grubs that are in early instar stage often can be found making tunnels in the top 4 inches of soil, doing so to loosen the soil making it easier for them to eat the thatch. Grubs rarely eat enough turf roots to cause significant damage. However, if the grass is stressed due to drought and is maintained at a very short height, grubs can easily inflict damage to your grass. Not only do grubs feed on grass, they also eat underground plants like carrots and sweet potatoes. June bug beetles have been shown to injure many varieties of fruit that is ripening.

June Bugs Control Methods

Make sure that June bugs are present before you take measures to eradicate them. It is important to remember that not only grubs make mounds in grass, earthworms do to.

Cultural Control

Using nonchemical approach to control June bugs is a viable option. If you maintain a healthy lawn and over seed thinned-out areas in the fall, it will reduce the weeds for the following spring. There are parasitic nematodes that are available to suppress June bug grubs. Two main species that are available to suppress grubs are Heterorhabditis spp and Steinernema spp. A few important notes about doing this method: be sure to check the expiration date due to the fact that they do not have a long shelf life. Read and follow the directions on the label. Finally, remember that nematodes are living organisms and need to be handled with care.

Chemical Control

Using a late-summer to early fall curative application is the most common method in controlling June bugs. Sadly, this treatment is completed after the grubs have already made a noticeable amount of damage to turf. Be sure to carefully read the label for cautions and proper application. It is extremely important to never spray on days that are windy. Contact insecticide should be applied later in the day due to the fact that grubs are more active at this time, moving closer to the surface. Foliar sprays of contact insecticides provide immediate knockdown control for mature June bugs, such as acephate, carbaryl, pyrethrins and pyrethroids.

Latin / Alternative June Bugs Names

  • -Cotinus nitida
  • -Green June beetle

Sources

http://ento.psu.edu/extension/factsheets/green-june-beetle

http://ipm.ncsu.edu/AG268/html/green_june_beetle.htm