Issue 11, July 11, 2011
Scouting Report
Bagworms have settled down to feed and are treatable throughout the state. Noticeable damage is being seen in southern and central Illinois. Bacillus thuringiensis kurstaki, spinosad (Conserve), and pyrethroids provide very effective control, even on larger larvae. Carbaryl (Sevin) and chlorpyrifos (Lorsban) provide adequate control only on small larvae whose bags are one-half inch or shorter.
White grub control decisions rely on rainfall over the next couple of weeks. Most turf areas continue to be green and lush throughout the state. Many of the Japanese beetle and masked chafer eggs have been laid. However, if there is little rainfall and high temperatures over the next couple of weeks, unwatered turf is likely to go dormant. This is likely to result in significant amounts of egg-laying in irrigated turf and damaging grub numbers in these areas without treatment. If this occurs, preventative application within the next month of a long-lasting white grub insecticide is recommended. This includes chlorantroniliprole (Acelepryn), clothianidin (Arena), imidacloprid (Merit), or thiamethoxam (Meridian). (Phil Nixon)
Author:
Phil Nixon