Insect Management Update
Dr. Ames Herbert recently posted an article on the Virginia AG Pest Advisory about “worms” in peanuts. I thought it was very good and comprehensive and I agree with it 100%.
We believe that too many peanut fields are treated for worms in some years. We both feel that the varieties we grow today as compared to 25 years ago are a whole lot more tolerant to the stresses encountered in the field. However, we do seem to be observing more of a mixed bag of problems including budworm and beet armyworms and based on their early arrival this year, maybe even some fall armyworms. We also have concerns about resistance to pyrethroid insecticides, but some of our issues with lack of control from pyrethroids are probably due to the presence of some budworms in the fields which are not going to be controlled by these products. Budworms are most likely only going to be a problem if they get into the peanuts early, such as what happened in SC a few weeks ago. Once the peanuts get bigger, budworms usually aren’t as damaging.
The worm complex in peanuts can be hard to identify. This is especially true for separating out corn earworm and tobacco budworm. You have to look carefully at mandible (jaw or teeth) on the underside of the head and even then, it is often a bit of a challenge to separate the two. Since there is a lot of variation in how the various caterpillars look, I have attached some links that have multiple photos to help you figure out what is present. Hope this helps.
Fall armyworm (photo from Department of Entomology, University of Kentucky)
Beet armyworm (photo from Department of Entomology & Nematology, University of Florida)
Corn earworm (photo from Department of Entomology & Nematology, University of Florida)
Tobacco budworm (photo from Department of Entomology & Nematology, University of Florida)