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Lesser Cornstalk Borer and Spider Mite Update

As I drive across the state I see areas that have obviously received decent rainfall over the past month. On the other hand, there has been no measurable rain at my house in four weeks, and I am not the only one. It is DRY, and it is no secret that lesser cornstalk borers (LCB) thrive in hot, dry weather. If you haven’t scouted your peanuts in a while, now is the time to do so. If LCB is present, now is the time to treat for them. Peanuts pegs and pods are developing, and we need to protect the crop from LCB feeding. It might make sense early in the season to take a wait and see approach when LCB populations are low, but now is not the time for wait and see. If LCB populations get out of control in a field, it will be very difficult to reign them back in. If you do not have LCB in your fields, there is no reason to apply a “preventative” insecticide. Scout, and spray when the pest is present.

I have posted several articles about LCB on this blog over the years. If you are interested in reading more about this pest, you can select “LCB” under the “Categories” tab at the right of your screen to see all the previous articles.

There have been reports of two spotted spider mites in Georgia peanut fields in 2019, and infestations will almost certainly become more common if dry conditions continue. PLEASE do not apply a pyrethroid insecticide to drought stressed, non-irrigated peanuts without discussing the application with your county agent or consultant first. Pyrethroids will flare mites.  We need to be watching peanut fields closely for signs of mite infestations. They will usually show up at field margins and move inward as numbers increase. It is possible to spread mites across a field or from field to field with tractors and spray equipment, so be observant and use caution. Though spot spraying field edges sounds like a good idea for controlling spider mites, I have rarely seen good results from this approach. If plants are already turning yellow or brown, you can be nearly certain that mites have already moved into the interior of the field.

If you have questions about LCB or spider mite management, you can contact your local UGA County Extension agent.