Leafhoppers, Grasshoppers, and Beetles, Oh My!

Adult red-headed flea beetle (P. Beauzay, NDSU)

By Kelley Tilmon, Andy Michel

As the summer progresses we are receiving reports of insect problems often encouraged by hot, dry weather.  Last week we reported on spider mites and especially if you are in an area of continued dry weather we recommend scouting your soybeans and corn  https://agcrops.osu.edu/newsletter/corn-newsletter/2020-22/watch-spider-mites-dry-areas .

Some areas are also reporting increases in young grasshoppers in soybeans, another insect favored by dry weather.  Grasshoppers of often start on field edges so early scouting may allow for edge treatment.  Japanese beetles are another common defoliator of soybean that are starting to appear.  Both of these pests fall into a general defoliation measurement, and we recommend treatment if defoliation is approaching 20% on the majority of plants in post-flowering beans.  Download our guide to estimating defoliation in soybean at https://aginsects.osu.edu/sites/aginsects/files/imce/Leaf%20Defoliators%20PDF_0.pdf Continue reading

Lookout for Spider Mites

Soybean leaves showing speckling.

With continued dry weather, spider mites are one of the main pests to remain vigilant about in field crops.  They will often show up in field borders first as they move in from other habitats, for example, if nearby ditches have been mowed.  Spider mites are difficult to see.  Look for injury signs — yellow spotting or stippling on the upper side of leaves.  In soybeans, this damage usually begins in the lower canopy and progresses upward as the mite population increases.  Heavily infested leaves may also have light webbing similar to spider webs. Continue reading