It's the time of year that Green June beetles are spotted in large clusters around Central Texas. These beetles are velvety green, about one inch long and 1/2 an inch wide. The top is a dull green with yellow-brown markings on the wings and the underside is bright, metallic green with yellow-orange markings. Larvae are creamy white, c-shaped larvae with well developed head capsules and legs. Larvae (also called grubs) can grow over an inch in length.
|Green June beetle. Photo by Drees.|
To check for grubs, which are the damaging stage, cut several 4" x 4" soil sections in different areas of the turf and look in the root zone and soil for presence of grubs. It is possible to have grubs in the turf and not see any damage. If a turf is kept healthy, then it can withstand some damage from insects.
If you feel the need to treat for grubs, you can try nematodes or pesticides. When choosing nematodes, be aware that they require moist soil to move and parasitize prey. If you are under watering restrictions, this may not be a feasible option. Pesticides come in granular or liquid formulations with systemic (i.e. the active ingredient imidacloprid) or contact (i.e. the active ingredient cyfluthrin) modes of action. Contact products need to come in contact with the grub for it to kill the insect, so it will require watering in to carry any pesticide to the soil where the grubs are located. Systemic products also require watering in, but the turf will take up the active ingredient into the roots and the grub will get a dose when it feeds on the turf. Granular products should be applied with a properly calibrated spreader and then watered in. Always read and follow all label instructions.