Issue 9, June 18, 2012
Japanese beetle has emerged in central and northern Illinois. Thanks to Wayne Ladage, Alma Gaul, and Alice Cassens for their reports. Refer to issue number 7 of this newsletter for additional information. It is still too early to determine whether adult numbers are large enough to result in high white grub numbers in turfgrass. However, we have had enough hot, dry weather in most areas of Illinois to set us up for concentration of egg-laying and resulting high grub numbers in irrigated turf areas.
False spider mites have been found attacking hemlock. They also attack yews and other conifers. Damage appears as light areas on the leaves. The mites are reddish and found on the stems and leaf undersides.
False spider mites on hemlock twig.
False spider mite damage to hemlock.
Honeylocust mite and oak mite become damaging during hot, dry weather. Honeylocust mite causes the leaflets to turn yellowish. Leaves heavily damaged by oak mite will appear grayish on the upper surface. Both are close relatives of twospotted spidermite and control is the same. (Phil Nixon)