No. 12/July 25, 2011
White Grubs
The recent hot, dry weather and more of the same predicted has set us up for white grub damage to turfgrass this year. How severe will not be very predictable until early August when most of the grubs have hatched.
Green June Beetle
Green June beetle adults have been reported in large numbers. These beetles are stocky, green, and about three-fourths inch long. They make a loud buzzing sound when they fly and apparently prefer to fly into upright objects, including people.
Cicada Killer
Cicada killers have recently emerged in central Illinois. These one and one-half inch long wasps are black and cream with transparent reddish wings. A female cicada killer captures an annual cicada that it paralyzes by stinging, drags it down into her underground burrow, and lays an egg on it.
Twospotted Spidermite
Twospotted spidermites become numerous and thrive in hot, dry weather. They are attacked and killed by fungal diseases that do better in moist conditions. The spidermites take longer to grow up in cooler conditions, giving the fungi more time to kill the mites.
Got Wilt?
Hot, dry weather causes stress to plants as well as people. Wilting is a normal plant response to a lack of water, but severe wilting, partial-plant wilting, and flagging are all symptoms of Verticillium wilt. This disease is common and recurring in Illinois. The causal fungi are found throughout the state.
Rose Rosette: It is Still Lurking in Roses
Rose Rosette disease is caused by what is thought to be a "virus-like" disease or a double-stranded RNA and is known to affect plants in the Rose family. Multiflora rose, often considered to be an invasive plant species, is very susceptible to this disease.