Hot, Dry, and Spider Mites, Oh My!

July 7, 2016 8:53 AM
Blog Post

Spider mites the end of June or first part of July? Our hot and dry weather here in southeastern Iowa have provided favorable conditions for spider mites. Typically we do not see spider mites reaching economically damaging levels until late July or early August when conations (hot and ry) are favorable for their growth.

The last time we may remember really having an issue with spider mites was four years ago back in 2012. Somewhat cooler temperatures and rain can help take care of the problem.  

Erin Hodgson recently wrote the ICM article, "Spider Mite Injury Confirmed in Soybean," which has some helpful tips on scouting and managing spider mites. 

Below are some images from a soybean field in Washington County that I found spider mites in. 


Stippling on a soybean leaf caused by two spotted spider mites. Photo taken July 4, 2016. 


Twospotted spider mites can be difficult to see with the naked eye. Shaking leaves onto a white piece of paper and looking for moving spider mites can be helpful in scouting for spider mites. A hand magnifying lens is also recommended when scouting for spider mites. Spider mites are typically green or cream in color when feeding on corn or soybeans. They may also appear to be orange to red if conditions are unfavorable for their growth. Photo taken July 4, 2016. 

Additional resources on twospotted spider mites:

Early Confirmation of Twospotted Spider Mite (ICM Article, 2012) 

Scout for Twospotted Spider Mites This Summer (ICM Article, 2012) 

Author: 

Rebecca Vittetoe Field Agronomist in SC Iowa

Rebecca Vittetoe is an extension field agronomist in southeast/south central Iowa. Educational programs are available for farmers, agribusiness, pesticide applicators, and certified crop advisors.

Areas of expertise include agronomy, field crop production and management of corn, so...