Farm Scene for the Salisbury Post
Darrell Blackwelder
October 9, 2003

    Recent rains over the past few days have forced white grubs from the soil. Now is an opportune time to control these immature insects before they burrow deeply into the soil. Grubs burrow deeply into the soil as temperatures drop making them more difficult control with pesticides.
    These grubs are immature larvae of Japanese beetles and June beetles. These are the most common grubs found in lawns and plant beds, although there are many other immature insect species lying just beneath the soil.
Adults lay eggs in late June and July which quickly hatch to small grubs. Japanese beetle grubs feed on grass roots causing large dead spots in lawns. However, June beetle larvae feed on decaying plant matter in the upper surface of the soil. These can be easily identified by their curious habit of crawling on their backs across the soil.
June beetle larvae are large, off white grubs about the size of a person's thumb. Japanese beetle and other beetle larvae are much smaller and curl into a C shape.
    As these grub mature and grow larger, they burrow deeper into the soil, up to 8 inches, making adequate control difficult. The soil is still warm, providing an effective time to control these pests before they burrow deeply in escaping cold weather. Beetle grubs can also be controlled in early spring in March and April but use higher insecticide rates must be used increasing maintenance costs and also less effective.
    Also, controlling grubs now is important because it eliminates the food source for moles. Moles feed almost exclusively on white grubs and other insects in the soil. Even though moles do not really do that much damage to the turf itself, most prefer not to have them in their lawn and shrub beds.
    There are quite a few insecticides that are labeled for grub control in lawns and landscapes. The most popular insecticide for grub control is diazinon. This insecticide is very effective and still available from local retail garden centers. Merit is solid alternative if diazinon is unavailable and sold at some retail outlets in Rowan County. Use fertilizer spreader to apply the pesticide just as you would any granular fertilizer on lawns and shrub beds. It's best to apply this pesticide just before a rain or irrigate after application. However there is one exception; controlling June beetle larvae with Sevin. June beetle larvae can be controlled with Sevin wettable powder; however, you do not irrigate the insecticide in after application.
    As with all pesticides, always read and follow the label before application. Please contact Cooperative Extension if you have any questions concerning pesticide applications.