Flaring Spider Mite Populations in NE and KS Soybeans
Spider mites on soybean stems
Rainfall throughout NE and KS has been variable this year, and areas that have gone without are experiencing flares in spider mite populations, particularly in south-central NE and north-central KS. Be sure to scout fields early and often, as spider mite damage can sometimes look similar to damage caused by drought conditions.
In order to identify and manage spider mites, Syngenta recommends these tips:
- Utilize a paper test. Go to the suspected area and place a plain white sheet of paper along the plant on the ground. Shake the plant and leaves over the paper and wait a few seconds. When what looks like “dust particles” begin to move, it is most likely spider mites. Confirm this by using a hand lens and looking for 2 spots on the abdomen of the insect.
- Be alert during hot and dry periods. Two-spotted spider mites become more of an issue in prolonged hot and dry periods. The damage of piercing leaves and feeding on plant juices adds stress to the plant. This also is why the plant symptoms may resemble leaf burning.
- Continue to scout. Once mites are identified, it’s important to continue to scout in that field area every 5 to 10 days. Most spray treatments that are labeled for control of two-spotted spider mites have very short lived residual control and populations can spike very quickly, even after an initial treatment.
- Use proper rescue treatment timing. Prior to pod set, treat when 20-50% of the leaves are discolored. After pod set, treat when 10-15% of leaves are discolored. Take into consideration plant size, stress impact and short-term weather forecast.
According to Cropwatch at the University of Nebraska-Lincoln, low-volume applications of insecticides and miticides may not reach spider mites on the undersides of leaves. Aerial applications are generally more effective very early in the morning or in the evening. Second applications may also be needed if the first application kills off the natural insect predators of spider mites.
When local thresholds are reached, apply a miticide like Agri-Mek® SC miticide/insecticide. With its extended residual control and tank-mix convenience, Agri-Mek SC protects yield that may be vulnerable to damaging spider mites. It also targets spider mites on both the upper and lower leaf surfaces, giving you peace of mind that your fields are protected against spider mites and other pests.
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