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Green June Beetle Grub Activity This Spring

May 5, 2008
by Rick Brandenburg

Green June Beetle
Green June Beetle White Grub
White Grubs

This spring I have received a lot of calls concerning green June beetle grub activity in all types of turfgrass and pastures. Green June beetle grubs are a problem that has increased throughout the Southeast and mid-Atlantic states and we don’t have a good explanation why this is happening. Despite the dry summer last year green June beetle grubs seemed to do just fine and they overwintered and the grubs are now causing soil push ups and tunneling in many lawns, golf courses, ball fields, etc.

Green June beetle grubs are a little different from the other grub species in that they tunnel near or on the soil surface at night and you often see a lot of disturbed soil, mounds and holes in the ground. Typically we don’t see too much activity in the spring, but this year it seems like they are everywhere. The green June beetle’s life cycle is similar to that of a Japanese beetle, but pupation, emergence of the beetles, and egg laying is about a month later for the green June beetle. Preventive insecticide applications are usually made in July rather than June. More information on this pest and other grubs can be found by clicking on http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note67/note67.html.

The BIG question I am receiving right now is whether it is worth treating at this time of year. The answer is MAYBE! It depends upon your turf situation and the amount of damage you have and can tolerate. In some situations treating with an insecticide such as Dylox® (trichlorfon) or Sevin® (carbaryl) will provide good control if the soil is moist and the night time temperatures are at least in the mid 50s. Keep in mind that these grubs should stop feeding around late May in most areas and that the damage they cause is about to come to an end for this spring. Will controlling some grubs now reduce the next generation this fall? Probably, but don’t depend on it as a means of preventing the next generation as you won’t get 100% control and beetles will fly in from many areas.