Origin:
At least 2 dozen of these native beetles occur in North America.
Biology:
The life cycles and habits of this group are similar to those of the June and May beetles in the genus Phyllophaga. The adults feed on many different plants, including the needles of pines and foliage of other plants, and the larvae feed on the roots of grasses, nursery plants, some agricultural crops, and ornamentals. Peak emergence of these beetles is often in May through June, as their common names suggest. Life cycles require from 1 to 4 years to complete, with 3-year cycles the most common for our pest species. The larvae may move up and down in the soil periodically during the year to coincide with winter temperatures or hot and dry summer temperatures. Winters are spent deeper in the soil as either second or third instar grubs. Adults often will be attracted to lights at night.
Identification:
The adult beetles are unmistakable due to their large size (an inch or longer) and alternating white and dark brown to black stripes running lengthwise down the elytra. There usually will also be a white stripe in the middle of the brown thorax and a white stripe on either side of the thorax. However, at least one species does not have these stripes and is a solid brown color. The legs are long and often stick out to the sides on dead specimens. The larvae have the characteristic C-shape of white grubs but may tend to stay coiled when disturbed compared with the Phyllophaga grubs.
Characteristicts Important to Control:
Residual contact insecticides can be applied to plants the adults gather on to kill them before they have the opportunity to mate and deposit eggs. Adult beetles normally feed at night. Contact insecticides can be applied to turf to kill the larvae, timed to when the larvae are feeding in the root zone of the turf grasses. Granular insecticides can be very effective once watered in to move the active ingredient into the soil.
