Issue 15, August 28, 2009

White Grubs

White grubs appear to be low in number and spotty this year in central and northern Illinois. In my surveys, it has been difficult to find any grubs at all, and I have not heard of any treatable infestations. With the number of adult Japanese beetles in southern Illinois, damaging infestations are probably widespread in that area of the state.

Although adult beetle numbers were low this year in central and northern Illinois, some locations reported locally high numbers which may result in damaging white grub infestations. However, the periodic, timely rainfall experienced through Illinois this growing season have caused more eggs to be laid in unwatered as well as irrigated turf. Also, the extra rainfall results in more vigorous root growth, allowing the grass to grow roots faster than the grubs can eat them.

Fewer eggs with a lower area density coupled with moist soils allowing vigorous turf root growth should translate into only minor damage in scattered locations in central and northern Illinois. Trichlorfon, sold as Dylox, is the insecticide of choice to provide quick, high level control of damaging infestations.--Phil Nixon

Phil Nixon

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