Are you receiving our Grub Control Application? If not you could be the victim of what’s lurking below the soil line……Grubs! Timing is very important for this application so call now it you haven’t already scheduled your Grub Control Application.
White Grubs: A Common Turfgrass Insect
White grubs are the primary insect problem many homeowners face annually. Damage is usually noticed in late July to early August and can persist into September. The earliest symptoms of white grub feeding on turfgrass roots is a gradual thinning and weakening of the turfgrass stand. Damage may progress from sudden wilting of the grass, even with adequate moisture, to patches of dead grass. Small or large patches of dead or dying grass will have roots pruned so that sod can be pulled up or rolled back like a loose carpet. Numerous C-shaped whitish larvae with a brown head will lay in the upper soil directly below the dead sod. Mammals, such as skunks and armadillos, or birds digging for grubs can also cause additional turfgrass damage.
Adults are scarab beetles, May/June beetle, masked chafer, Japanese beetle, and green June beetle. These are the primary white grub species many homeowners face with the May/June beetle and masked chafers being the most common. Identification of white grub species can be made by: time of the year the grub is present, size of the grub and raster patterns on the abdomen of the grub (see diagrams).
Damage is typical wilting and small dead patches of sod. These beetles have a 3-year life cycle. Adult beetles can be damaging to trees and ornamentals. White grubs should be treated during late July to early August to control any newly hatched larvae. However, during the second year of the grub’s life cycle, treatments can be made from April through September.
Turfgrass infested with this species exhibits the typical white grub damage. Wilting, irregular dead patches of turf are the symptoms. These beetles have a 1-year life cycle. Treat grubs about four weeks after the adult beetles start to emerge when egg deposits begin to hatch in late July to early August.
These beetles are now considered to be state-wide in Missouri. Grubs feed on roots of turfgrasses and cause a wilting appearance and gradual thinning, however we generally do not see large amounts of turf damage specific to Japanese beetle grubs. Adult beetles can be damaging to about 400 host plants of both turf and ornamentals. Adult females will lay about 200 eggs per season, throughout the summer months. Therefore, we do not have a single egg laying time frame. Using a long-term residual product will work best to cover multiple egg laying episodes. Adult beetles can be treated at any time. If large numbers of adult beetles are noticed defoliating trees and shrubs, a preventative long-term residual product may be warranted.
Green June Beetles
Feeding activity of these grubs rarely causes severe turf damage. Rather, the damage to a lawn generally is mechanical in nature. The grubs burrow in and out of the turf, which produces mounds. These beetles are attracted to soils with high organic materials. The decaying organic matter in the soil is the primary food for this grub. This white grub is large, 1 ½ inches in length.