Issue 12, July 16, 2010
White Grubs
Preventative treatment for white grubs is recommended to watered turf in those areas of the state where rainfall has been slight and non-irrigated turf is dry and dormant. In these dry areas, Japanese beetle and masked chafers will concentrate their egg-laying in irrigated areas, where the turf is green and actively growing and the soil is moist and easy for them to burrow into to lay eggs. This egg-laying is likely to result in population numbers that will be high enough to cause severe turf damage later this summer and fall.
Rainfall has been spotty in Illinois over the last two weeks. Some areas have continued to benefit from periodic rains, but even nearby areas have been dry. A good example is that Champaign, IL has received 1.25 inches of rain over the past week, but I have received 5.0 inches during the past week at my house, which is 15 miles away.
If high grub populations are expected, apply chlorantroniliprole (Acelepryn), clothianidin (Arena), imidacloprid (Merit), or thiamethoxam (Meridian). Irrigate with at least one-half inch of water to move the insecticide down into the root zone where the grubs are located.--Phil Nixon
Author:
Phil Nixon