Insecticides for Fall Armyworms After Digging Peanuts?

The quick answers to your questions are as follows.

• Can fall armyworms feed on pods of inverted peanuts after digging? Yes, it is possible.
  
  
• Does this commonly happen? No, not really in an economically-impactful way.
  
  
• Should you apply an insecticide? Not usually, but there are rare exceptions.

Here’s a more detailed look into the topic and some factors to consider.

The Threat of Fall Armyworms After Digging Peanuts

Fall armyworm is classified as a foliage-feeding worm and can be present in peanut fields.

The NC State Extension is quick to explain, “we have seen them [fall armyworms] crawl to the top of inverted plants at digging and feed a little on the pods” but this is a “seldom seen scenario.”

Entomologist Rick Brandenburg notes that fall armyworms “have the potential to damage peanuts but are not as aggressive of feeders as corn earworms or budworms. … In the past, there have been instances that when peanuts are dug, the fall armyworms move up and feed on pods. I really don’t know how much damage these do, but it can be a scary sight.”

Thresholds for Spraying Insecticides to Control Fall Armyworms

The Clemson Extension points out, “Fall armyworms are not usually an economic problem on peanut, but they can occur in very high numbers during outbreak years.”

So, how many fall armyworms are too many?

The UGA Cooperative Extension says, “The treatment threshold level of foliar feeding worms in peanut is 4 to 8 per foot of row no matter which one it is (armyworm, cloverworm, looper, velvetbean). However, properly identifying the caterpillar is important in order to decide which chemical to use.”

The Extension further cautions, “Pyrethroids will not control Fall Armyworms … Don’t apply an insecticide if it’s not needed and … make sure the worm is properly identified before making a choice on which product to use.”

If peanuts are healthy and not stressed, the threshold to warrant treatment may be even higher. The NC State Extension says, “Currently, the threshold for worms is eight to 10 per row foot.”

If populations of fall armyworms are less than this in your fields, then insecticide treatments are not warranted.

Pre-Harvest Intervals to Keep In Mind When Choosing Insecticides

When applying insecticides on dug-up peanuts, growers need to be particularly mindful of harvest restrictions since the last step of combining is right around the corner.

“If you see a lot of them [fall armyworms] and fear the seldom seen scenario of them feeding on pods after digging, there are only two options I am aware of,” according to the NC State Extension. “Blackhawk has a 3-day harvest restriction and Prevathon has a 1-day harvest restriction. Everything else is 14 days or longer.”