What is in this article?:
- Cotton at critical stage for stink bug damage
- Choosing an insecticide
• North Carolina State University Entomologist Jack Bacheler says, “Weeks 3 through 5 of the bloom period is the time interval when the levels of stink bug-susceptible bolls are at their highest.
• This is also the time when a 10 percent damage threshold should be used.”
Cotton in most areas of the Upper Southeast is ahead of the five-year schedule of growth for mid-July and is at or nearing its most vulnerable stage for stink bug damage.
North Carolina State University Entomologist Jack Bacheler says, “Weeks 3 through 5 of the bloom period is the time interval when the levels of stink bug-susceptible bolls are at their highest. This is also the time when a 10 percent damage threshold should be used.”
He adds, “Remember that our goal is to reduce or eliminate an economically-damaging population of stink bugs, not to ineffectively try to reverse boll damage that’s already taken place.
Clemson University Entomologist Jeremy Greene says there are a couple of good ways to check for stink bug infestations. The key to both is to start scouting for stink bugs when small bolls appear.
The first method is to randomly select at least 25 bolls that are at least one inch in diameter per field and add one additional boll for each acre exceeding 25 acres, he says.
Each boll should be broken open and the carpal walls, lint and seed should be examined for injury symptoms, including warty growths on the carpal wall and discolored lint and seed, Greene says.
Growers can also rate an infestation based on numbers of stink bugs by using a beat cloth or beat pan. Carefully approach and shake the plants on at least 30 total feet of row from 10 three-foot samples. When going by numbers of stink bugs, one or more stink bugs per 6 feet of row indicates the need for an insecticide.