Thursday, August 18, 2022

Alabama Cotton Insect Situation: August 18, 2022

We are beginning to see some open bolls across south and central Alabama, the end is in sight. Not much has changed over the past week with our cotton insect situation. We are still fighting the bug complex in many fields across Alabama. In addition to tarnished plant bugs and stink bugs, we are also starting to observe some clouded plant bugs and leaf-footed bugs as well.

Cotton

SLWF

We are still in the early stages of the silverleaf whitefly (SLWF) situation in our areas with historic outbreaks (some parts of the Wiregrass). It is still not time to panic, but there are some fields infested that need to be watched.

Fields to be alert of include any of or a combination of the following:

  • Late planted
  • Drought stressed (hot, dry weather and/or dryland)
  • Low beneficial insect populations (fields with recent insecticide applications)
  • Hairy leaf varieties

Below is a copy of the SLWF handout from our colleagues who have a lot of experience fighting these critters at UGA.

SLWF Handout - Click to Enlarge

Bug Complex

Adult leaf-footed bug
While the presence of clouded plant bugs doesn’t necessarily change our insecticide recommendations, the presence of leaf-footed bugs would. In general, pyrethroids do not provide as good of control of leaf-footed bugs as the organophosphates do. That leaves us with 6 oz of Bidrin or 0.75 lbs of acephate. Due to the silverleaf whitefly (SLWF) situation in the historic SLWF areas (some parts of the Wiregrass), I would avoid Bidrin at this point and go with acephate. While we still don’t fully understand the reason, Bidrin really seems to exacerbate a SLWF infestation. In areas outside of this localized situation, Bidrin and acephate are both in play, depending on the availability of each.

Many of the people we have talked to have said they are getting ready to put out their “clean up shot” and walk away. Another season is beginning to wind down, but we need to keep scouting our later planted cotton and be prepared to protect bolls as needed.

Soybeans

Defoliating caterpillars (soybean loopers and velvetbean caterpillars) continue to build and require treatments in fields across central and south Alabama. We are watching traps closely in north Alabama to monitor when populations should be expected there as well. In addition to caterpillars, we are still fighting stink bugs, both the traditional species and the redbanded in many fields. Proper ID is critical or all of these species as concoctions to kill different species complexes may vary greatly.

Take Home Messages

While a fair amount of our cotton is out of the woods, we need to keep scouting in later fields and be prepared to take action when necessary. Be on the lookout for SLWF in areas with past experiences. Scout and properly ID which insects are in soybeans to make the most economic control options possible.

If you would like to provide reports or observations on the insect situation from your region, please let us know. You can reach Scott Graham at 662-809-3368 or scottg@auburn.edu or Ron Smith at 334-332-9501 or smithrh@auburn.edu.

As always, if we can ever be of any help, please let us know.