Issue 9, June 18, 2010
Warm Spring Causes Early Insect Emergence
Central and northern Illinois has had a warm spring this year. This is probably causing several insects including bagworm, Japanese beetle, and the masked chafers to emerge early this year in those areas of the state. Southern Illinois has had more typical spring temperatures, resulting in more average insect development in that area of the state.
Overwintering white grubs, both Japanese beetle and masked chafer, rise to feed in the turf root zone when it warms to 50 degrees F. In Champaign, there were 14 days with a soil temperature of at least 50 degrees F in March and April of 2009, whereas there were 37 days in 2010. In DeKalb, there were 13 days with a soil temperature of at least 50 degrees F in March and April of 2009, whereas there were 31 days in 2010. In Carbondale, there were 53 days with a soil temperature of at least 50 degrees F in March and April of 2009, but only 43 days in 2010. The soil temperatures were similar in 2008 and 2009.--Phil Nixon
Author:
Phil Nixon