Common Name: Grubworm
Scientific Name: Varies
Description: White grubs are “C”-shaped larvae, up to 1 inch long, with cream-colored bodies and brown head capsules. They have three pairs of legs, one on each of the first three segments behind the head. Adult beetles, commonly referred to as May beetles or Junebugs are ½ to 5/8 inches long, and reddish brown.
Pest Status: Larval stages eat roots of grasses, vegetable and ornamental plants; Adults can be a nuisance around lights at night in early summer; medically harmless.
“Grub” is a catch-all term for the larval, or worm, stage of many kinds of beetles. May beetles (also called Junebugs), Japanese beetles, Masked Chafers, Billbugs, Asiatic Garden Beetles and others all are grubs in the soil prior to emerging as beetles during the growing season. Grubs hibernate during the winter months and then they must come up in late spring to nosh grass roots for a few weeks so they then can pupate from grub to adult Japanese beetle or June beetle. In the Northeast, Japanese beetle grubs are the most common pests of residential lawns. Grubs are plump whitish colored worms that grow 3/4 to 1-1/2 inches long. They have 3 pairs of legs and tan heads with large, brown-black mouth parts. They rest in a characteristic C-shaped curl just under the soil surface in planted areas or turf, where they feed on roots of ornamental plants and lawn grasses. They typically are found in irrigated lawns, though non watered lawns are not at risk. other factors that can lead to poor rooting and are mistaken for grubs. For example, lawns in shade areas often have weak roots and are pulled-up easily. Grubs do not typically appear in shade lawns. It takes only 5 white grubs per square foot in a lawn with only two inches of roots to virtually destroy that lawn if nothing is done. Since the grass roots have been destroyed, the lawn will appear yellow in patches, just like the lawn is dying out. Therefore, the damage looks quite similar to symptoms of dryness. Another sign of grubs is damage from skunks and raccoons digging up lawns in search of grubs to eat. This usually happens at night.If significant grub damage occurs, the lawn will need some renovation work in early fall.It’s wise to monitor the lawn as we advance into late summer and be ready to act if grubs start to appear. Watch for grass areas going off-color and just starting to brown, in particular those areas that have been irrigated. Check the root zone for small white grubs. Insecticides such as Diazinon or Trichlorfon (Dylox) can be applied when grubs are first noticed to prevent large-scale damage. Other insecticides such as Imidacloprid (Merit) or Halofenozide (GrubEx) can be applied prior to noting damage, such as in late July to lawns likely to show damage (adult beetles present, irrigating lawn). All of these insecticides should be watered into the soil for best results, it’s also beneficial if your lawn is watered prior to application. That’s where we come in- our licensed, trained professionals will be happy to discuss what treatment plan is right for you.