Issue No. 18, Article 2/August 3, 2012
Twospotted Spider Mites: Scattered Infestations Remain
As the drought and high temperatures linger, scattered infestations of twospotted spider mites remain in some soybean fields across Illinois. I remember 1988 very well, along with the significant impact that this pest had on soybean production in the state. I took a quick look back and discovered that the first mention of twospotted spider mites in the Bulletin was that year, on June 3 (issue 9). Afterward, they were a continuing topic of coverage on a regular basis. For several days that year, extension entomologists Don Kuhlman, Kevin Steffey, and I did nothing but answer telephone calls all day long--our ears were actually sore at the end of each day.
Yes, I am dating myself--we didn't yet have email at the time of that outbreak. However, even if I factor in email questions about twospotted spider mites this year, it does not measure up (at least not yet) to the severe outbreak in 1988. Thank goodness, as we could use some good news this season.
By August 5 in 1988, we estimated that over 2 million acres of soybeans had been treated in Illinois for twospotted spider mites. Listed below are links to land-grant university information on managing that pest. Many changes have taken place since the late 1980s--one positive change is the ease with which information can be shared with producers and the broader agricultural community.
- corn.agronomy.wisc.edu/Management/pdfs/A3890.pdf (Adobe PDF)
It's not too late to make informed management decisions about spider mites in soybeans. I hope the information at these websites will help you make the appropriate decision for your farm.--Mike Gray