“I encourage everybody to scout for whiteflies, regardless of where your cotton field lies. With these conditions, whiteflies are going to spread. It is essential to be on time with a treatment when you hit threshold.
“Although insect growth regulators (IGRs) are the backbone of an effective whitefly program, a contact, systemic-type product that has activity on all life stages must be used when treatment goes out late. IGRs offer long residual activity but work slower because they are only effective on eggs and immatures.
“Stinkbug numbers range from low to moderate-plus. We should only treat fields based on scouting and thresholds. With our current situation with whiteflies, take the time to scout these fields and make sure we need to treat. Any treatment we use for controlling stinkbugs will affect beneficial populations, and we need to preserve beneficials to help us manage whiteflies.
“Corn earworm is surviving in two-gene Bt cotton. To date, numbers are below threshold, but some escapes are out there. Closely monitor populations and look for larvae in bloom tags, bloom-tag bolls, and small bolls. That’s where we are most likely to find them.
“We are treating fields for spider mites. With 10 days of hot and dry weather, spider mite populations really took off in places and required treatment. Spider mites are infesting a small percentage of the acres, but we do have hot fields.
“This past week’s weather really set back our crop, and a big part of our acres need rain in the next week. Otherwise, we’ll be in trouble. Number one, a widespread rain will help the crop. Number two, a big rain will go a long way towards minimizing spider mites and whiteflies.
Ron Smith, Extension Entomologist, Auburn University
“In cotton, we’re transitioning from plant bugs to stinkbugs. Plant bugs primarily are at sub-threshold levels, and many of them are clouded plant bugs. The damage and threshold for clouded plant bugs is the same as that for tarnished plant bugs.
“As we transition, keep in mind the significant difference between plant bugs and stinkbugs. Plant bugs feed on squares, which gives the plant time to compensate to some degree. Stinkbugs feed on bolls, which makes it more difficult for the plant to compensate. A plant is less likely to replace a boll than a square. With bolls in danger now, focus on stinkbugs, escaped worms, spider mites and whiteflies.
“Stinkbug populations are increasing. We have an explosion of Southern green stinkbugs in some cotton in southwest Alabama. We are in the period – third to sixth week of bloom – when we want to keep the internal damage to bolls below 10%. Boll damage in a field in Prattville was running 8% to 10% on Monday (7/20).
“It is hot, and where it hasn’t rained in a few days we are dry and crops are wilting. Moisture is critical in this stage. Bolls will fill over the next three to four weeks, creating a high demand for moisture.
“Hot, dry weather also speeds up spider mite production, so we likely will have calls on those later this week.
“Whiteflies will probably show up where we saw them in 2017, so watch closely. We don’t want to jump the gun, but we don’t want to be late with whiteflies, either.
“In soybeans, beet armyworms showed up this week for the first time since 1995. We found them in Monroe County at sub-threshold levels. The threshold is how much foliage is gone. Right now, we don’t see any foliage loss.
“We haven’t seen beet armyworms in a long time, but if they are in one field they might be in others. To identify beet armyworms, look for a green worm with a black dot on the fourth segment behind the head.
“Don’t treat until they reach threshold. It’s too early to start pouring money into soybeans, especially when we are likely to see velvetbean caterpillars and loopers before it’s over.”
Sally Taylor, Virginia Tech Extension Entomologist, Tidewater REC
“Every cotton field that I’ve been in this week has spider mites to some degree, although none of those populations were anywhere near economic levels. We need to play this safe – and that means avoiding broad-spectrum treatments. The last time we had a heavy spider mite year was in 2011. If we aren’t careful, we could find ourselves in that situation again.
“Most of our cotton is in the first week of bloom. We are still seeing some plant bugs, but we aren’t finding a lot of plant injury. Fields that have been hit hardest are those closest to corn, which is drying down or dead. Overall, though, pressure is still low.
“I’m not worrying about stinkbugs yet. We had high numbers of stinkbugs in wheat, but we had probably the lowest level of stinkbugs in corn since I started here.”
Dominic Reisig, NCSU Extension Specialist, Entomology, Plymouth, North Carolina
“We are seeing bollworm eggs at low levels in cotton. One consultant this week said he recommended treatment because bollworm eggs were at threshold level.
“The typical areas in our state are reaching threshold for plant bugs and may need treatment. Since the earlier scouting reports, other areas are now quiet. When we need to treat for plant bugs, especially this early, look to softer chemicals. I don’t want to put out harsh chemicals until we need to control bollworms or stinkbugs.
“We don’t normally spray for aphids, but they are worse than usual. Although aphids aren’t widespread, the early-planted cotton struggled and was under stress. Where aphids are adding to that stress now, treatment is justified because we don’t want to hold back that cotton any further.
“In soybeans, some beans are podding, and we are starting to hear questions about stinkbugs. So far, no one has reported stinkbugs in soybeans at treatment levels. I did hear from one consultant who chose to treat for green cloverworm. Generally, green cloverworm populations aren’t high enough to impact foliage, but that consultant saw foliage loss.”
Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina
“It’s hot and dry. Even when we get rain, it’s not long before we need another one in this sand.
“Insects are still pretty quiet. In cotton, we have more reports of fungus taking out aphids. Some cotton is moving into the stinkbug window. Certain fields have internal boll damage higher than 10%, which is the trigger for treatment in the third to fifth week of bloom.
“Although stinkbugs are showing up a little earlier in places, we won’t battle stinkbugs on a majority of the acres until the traditional window opens in August.