Name: Phylophaga Spp.

Alias: White grub, May beetle, June beetle or scarab beetle. The adults are an oval-shaped beetle and approximately ¾ inch long. They are usually dark brown. The larvae are a large, white grub with a dark head and pincers on the front, usually seen in the shape of the letter C. They remain in the larval stage for 3 years before emerging in the adult form, usually in late May or June.

Crimes: The grubs feed on grass in turf and pastures at about the soil level. Grass that is wilting, yellow or brown is usually a sign of grubs, but often the symptoms do not show up until after the damage is done. It is most obvious in the late summer. In the spring, the most obvious sign is loosely attached grass with little root system that can be pulled up easily.

Redeeming Qualities: None known.

Sentence: While they are often mistaken for other relatives (such as the Japanese beetle or the masked chafer,) June beetles rarely cause enough damage to merit control. However it doesn’t hurt to dissuade them and keep their populations low. Planting grass species that are resistant to grub feeding (such as endophyte-infected fescues) is a simple solution. Do not over fertilize or irrigate, both of which encourage grub habitat. Monitor for damage regularly. If you ever have more than 1 per square foot then you may need to use additional control. There is a wide variety of insecticides available at your local garden store that are labeled for grubs. With heavy infestations, trichlorfon (Dylox) has proven to be an effective method of control.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-745-6685 or email jsagers@uidaho.edu.