The word has been out since it was obvious things were drying out that spider mites like to move into soybeans in a dry year. Normally they move in from the edges of the field. They may only be in one side of a field. However, Purdue University experts say the tricky part is treating them before they move into the field itself.
Watch for stunted, bronze-colored plants. They've become easy to find around field borders and along roadsides. If it's your field, get out and see how far the infestation has spread into the field. Then check again in a couple days. If weather conditions don 't reverse and thwart it, the mite could spread.
Some farmers have taken preventive measures. If they have found spider mites along the edge of a field, they're spraying now and asking questions alter. One reason for doing so is that there are only two chemicals labeled for control, and if an outbreak begins to spread like wildfire, there may not be enough of those chemicals to go around.
The spider mite is not actually an insect. It is in the spider family. The actual name entomologists refer to it by is the two-spotted spider mite. It's the same culprit that caused a lot of yield damage before farmers stepped in and took action in 1988 during that drought.
Some farmers are only spraying the edges of fields where they see the mites at this point. If you choose that route, keep a close eye on developments in the field to make sure that some mites didn't escape because they were already farther into the field than you thought and that they set up shop again deeper into the field.
Miticides are expensive and not a good option for control, experts say. That's why grabbing on to insecticide that will work if you have the problem is critical.