Spider mite population could increase in field crops
Recent dry conditions could increase spider mite populations in corn and soybean.
As I type this Wednesday morning, July 6, 2016, the radar shows rain moving across Lake Michigan, but I don’t believe the radar anymore! Instead, I am increasingly worried about the possibility of spider mites, which I have already found on some ornamentals around my house. Last week, the U.S. Drought Monitor reported that in central and southern Michigan, 60-day rainfall was 50-70 percent of normal, while topsoil moisture was 60 percent short to very short. This deficit will only get larger because dry weather continued over the Fourth of July weekend across much of the state. While dry conditions are unfavorable for many insects, this is not the case for spider mites (the last spider mite outbreak was in 2012).
In case mites become an issue in the next month, I revised the spider mite bulletin for soybeans and created a new one for corn: Rating Infestations of Spider Mite in Soybean and Rating Infestations of Spider Mite on Corn. Both bulletins are also available at the Michigan State University Field Crops Entomology website. Managing spider mites is very frustrating, so let’s hope it doesn’t come to that.
Dr. DiFonzo’s work is funded in part by MSU’s AgBioResearch.