Cotton squaring and flowering is a few weeks away, and now is a good time for North Carolina farmers to think about treatment options for plant bugs, according to North Carolina State University Extension entomologist Dr.  Dominic Reisig.

In a recent blog post, Reisig points out that some North Carolina cotton farmers have already confirmed square loss from plant bugs and densities of plant bugs are above threshold for the Tar Heel State.

“Some fields have already been sprayed, as a result, and it is a good idea to be prepared. Although I think plant bugs are going to be an issue this year, I also think that we can easily manage them if we scout our fields correctly,” Reisig writes.  “What I hope we can avoid is spraying when we don’t need to, which can lead to resistance or flare other pests later in the season.  For example, no insecticide will control adults that remigrate into a field after a spray or stop squares that are being shed from droughty conditions with no plant bugs present."

According to Reisig, generally neonicotinoid-class insecticides perform well early in the season before flowering and often at lower rates.

“In general, a product that is killing a plant bug will likely kill related beneficial insects such as minute pirate bug and insidious flower bugs, damsel bugs, assassin bugs and big-eyed bugs," he writes. "However, these products are still much less harsh on the system than pyrethroid and organophosphate-class insecticides."

Later on in the season, neonicotinoid insecticides generally do not work as well, Reisig notes.

In another post, Reisig advises farmers to have a scouting plan and to  stick to their plan.

“I cannot urge how important it is to both monitor square retention and to check for plant bugs,” Reisig points out.  “Plant bugs aren’t the only cause of square loss- other stresses in the environment can cause this.  So you don’t want to spray a field where bugs aren’t the problem.  Also, plant bugs are extremely mobile, and can rapidly move in and out of fields.  Sometimes they may be present (especially adults), but not causing square loss.”

Reisig explains that weekly checks of upper square retention is the most efficient way to assess if plant bugs can either be ruled out as an economic concern at that time or if sweeping for the adults and nymphs is needed.