The Alabama cotton insect situation has started to pick up
over the past week. Plant bugs are becoming more consistent in some fields and applications
are going out. Aphids are beginning to somewhat settle down, and we expect to
start picking up fungus soon too.
Most of the calls we have gotten revolve around plant bug
management and when or if to use Diamond. In most cases, we still recommend Diamond
in fields that have already had one application for adult plant bugs in pre-bloom
cotton. Somewhere around 10-14 days after that initial application is an ideal
time to get it out, if treatable levels of plant bugs are present. This allows time
for eggs that were deposited to hatch so nymphs will be exposed to the Diamond.
If not, we have been recommending holding off on the Diamond, particularly in south
Alabama. Our reason is to save some budget for if/when jassids show up. We do
not know yet how many applications (or if any, but we suspect we will) we will
need to manage jassids. Budgets are tight and saving until applications are economically
justified (thresholds) will be critical this year.
We have also seen a fair amount of clouded plant bugs in south Alabama this year. Clouded plant bugs are slightly more aggressive feeders, and they prefer to feed on thumb-sized bolls, where tarnished plant bugs prefer to feed on larger squares. A common characteristic of clouded plant bug feeding is cat-facing (dark spotting) on the outside of the boll, similar to stink bug injury. Experience over the last couple years suggests that pyrethroids provide sporadic control of clouded plant bugs and should not be relied on for control.
 Adult clouded plant bug | ||
We are also approaching the time of the season when the new material, Vertento, has a good fit. In my experience, Vertento provides very good residual (≈3 week) control of plant bugs, stink bugs and spider mites (and probably cotton jassid too). To maximize the return of investment with this product, it should go out once cotton has slowed its vegetative growth (after bloom). Vertento is not systemic, so new growth is not protected. For this reason, we have found that spraying around the 2nd or 3rd week of bloom is a good timing to knockout plant bugs and get close to finish line on stink bugs too. We know, based on limited experience, it provides good control of jassids, but we need to do more work to see how long the residual control lasts.
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| Adult cotton jassid found in Headland on July 7, 2026 |
We are also seeing a ton of what we are calling “jassid
mimics” or “look-alikes” that are other leafhopper species that look similar to
but are not cotton jassids. These species do not cause hopperburn. If you are
currently finding immature leafhoppers easily, I think there is a very high
degree of certainty that it is one of the mimic species. The only way in the
field to know you are dealing with cotton jassid is to see adults with the two
black spots on the wings (image). We are starting to get heat, sunshine and popup
rain showers which will help the crop catch up, but also favors cotton jassid
growth and development. A few factors that favor cotton jassid growth and
development: hot temperatures (81-95F), high humidity (55-87%), sunshine hours
and moderate rainfall (increases humidity and plant growth).
To see an up-to-date map on cotton jassid detections across
the Cotton Belt, you can check out the Stop two-Spot Cotton Leafhopper
(Stop2SCL) website here (https://stop2scl.org/cotton/)
As always, if we can ever be of any help, or if you would like to provide input on the situation in your area, please don’t hesitate to reach out to your local Extension Agent or myself (Scott Graham: 662-809-3368) and Ron Smith (334-332-9501). For more information on thresholds and insecticide recommendations, visit the Alabama Cotton IPM Guide (IPM-0415). To stay up-to-date on the Alabama cotton insect situation, subscribe to the Alabama Cotton Shorts Newsletter, Alabama Crops Report Newsletter and Podcast, and the Syngenta Pest Patrol Hotline.
