Alabama Insect Blog

Thursday, September 4, 2025

Alabama Cotton Jassid Situation – Thursday, September 4, 2025

Alabama Cotton Jassid Situation – Thursday, September 4, 2025

The invasive two spot cotton leaf hopper (aka cotton jassid) has been confirmed in cotton fields in 18 counties across Alabama. Thus far, insecticide applications have been made in a timely manner, and fields have been protected. This is and will continue to be an evolving situation, but we have learned some things from our observations. The recent cold (or cool) front that moved through the state has seemed to slow down population growth. Cotton jassid numbers seem to be slower to build, which is a good thing.

Field Risks:

1. Fertility: In our observations, “weaker” fields seem to be at a greater risk of showing symptoms. There particularly appears to be a link between potassium levels and the crops ability to fight off jassids.

2. Planting Date: For now, cotton jassid infestations have been greatest in older cotton. That will likely change soon as defoliation begins, and these fields are no longer suitable hosts. This will likely put later planted fields at HIGH RISK of infestations.

Management Strategies:

1.Threshold: As we continue to learn about this insect, we are changing thresholds to avoid losses. Currently, our recommended threshold is 1-2 nymphs per leaf. Because there are several leafhopper species found in cotton, it is important to confirm adults in the field, or to see symptoms somewhere in the field before making an application.

2. Insecticide Strategy: We have done several insecticide efficacy studies as a group across the southeast. While several insecticides have been identified, Bidrin (6 oz/A) has been the most consistent and is generally widely available. Bidrin also has the added benefit of plant bug and stink bug control. Other materials that have provided good control include (alphabetical order): Centric (2 oz), Courier (12 oz), Sefina (10.5 oz), Sivanto (7 oz), Transform (1.5 oz). Note: Bifenthrin has NOT provided acceptable control.

3. Insecticide Termination: One of the most common questions we get is when to terminate applications for cotton jassids. The honest answer is, we don’t know. Based on our observations for how quickly cotton jassids can crash a field (as little as 2 weeks), we recommend protecting cotton up to 2 weeks prior to defoliation. This means that cotton should be protected through 20-25% open boll.

For the most update information on cotton jassid in your area, please reach out to your local Extension Agent.

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.

Counties where cotton jassid has been detected in Alabama as of 9.4.25

Tuesday, August 19, 2025

Tales of Insects: Tuesday August 19

Cotton. The cotton insect situation has been all over the board this year. Calls and reports have been that insects are sporadic. Heavy in some areas while others will likely go with no foliar insecticides for insects for the first time in years. We have reached (or rapidly approaching) insect cutout on early planted cotton. Below are a few guidelines for when to terminate applications:

1. Plant Bugs: Node above white flower 2 (NAWF2). That is, when there is an average of 2 node above the highly first position white flower, cotton is generally safe from plant bugs.

2. Stink Bugs: Bolls that are expected to make it in the basket should be protected until they are ~25 days old. Keep in mind that as we get later into bloom, the amount of internal boll damage (IBD) needed to justify an application increases. Weeks 3-6=10% IBD; Week 7=30% IBD; week 8=50% IBD.

3. Spider Mites: This can be a tricky call (as can be when to treat in general). A threshold for spider mites of 30-50% infested plants showing injury is the best we have. Some considerations for terminating treatments include age of the cotton and how bad the infestation is. Bolls that are expected to be harvested should be protected from mites until they are about 20 days old. How bad is too bad? This is hard to say, but you cannot walk away from a disaster. If mites are turning leaves red and defoliation can happen, action is needed.

Cotton Jassid: The cotton jassid (or two-spot cotton leafhopper) is an invasive insect originally from India. This insect was found in Puerto Rico in 2023 and in Florida in 2024. This insect has been widely detected in many counties in Georgia and has also been found at damaging levels in Florida and South Carolina. To date, while we have reports of cotton jassid in Alabama, we have not received reports or observed damaging levels in Alabama.

Cotton jassids are small (1/10 inch in length) leafhoppers that damage plants with sucking mouthparts and feed on the underside of leaves. Our initial observations indicate that they usually infest field edges (like SLWF). While infestions are low in a lot of cases, they have the potential to blow up quickly. This insect can turn over a generation in as little as 10 days.

To scout, turn an individual expanded leaf from one of the top 5 nodes and count cotton jassids on the underside of the leaf. We cannot identify species of nymphs but adults are easily recognized by two black spots on the wings. Plant injury includes yellowing of leaves on the outer edges or hopper burn or leaf puckering (see pics below). If you detect jassids in the field please contact your local Extension Agent for the most current information on thresholds and insecticide selection. This is an evolving situation and management strategies are subject to change. (Note: to date, cotton jassid has only been observed in commercial fields of the SE corner of Alabama, Henry and Houston counties.)

Adult and immature Cotton Jassids.

Cotton Jassid symptomology.

Soybean. The soybean insect situation has started to build in the the past week. We are receiving more reports of defoliating caterpillars and stink bugs across Alabama. In most cases, soybean loopers have not been a large portion of the defoliator mix, but there are enough to take notice.

Our threshold for defoliating caterpillars (loopers, cloverworms, velvetbean caterpillars) is to avoid 20% defoliation during reproductive stages. For soybean loopers (SBL), treatment is recommended if 18 loopers (> 0.5 inch) is found per 25 sweeps. Velvetbean caterpillar (VBC) and green cloverworm (GCW) threshold is 36 per 25 sweeps. Most labeled insecticides do a good job controlling VBC and GCW, while newer materials (Vantacor, Besiege, Intrepid Edge, etc.) are needed to control SBL.

In addition to our traditional stink bugs species, we have also heard of some redbanded stink bugs in fields in central Alabama. In most cases, they are just part of the complex and not the dominate species. However, some fields have had one or more applications for RBSB. Threshold for stink bugs is 6 per 25 sweeps* until R6. At R6 threshold is doubled to 8 per 25 sweeps for the next 7-10 days. While Pyrethroids provide good control at the high labeled rate, tank-mixtures of Pyrethroids and Acephate (or neonics) are needed to control RBSB. (*note: threshold for RBSB is 4 per 25 sweeps).

Monday, July 21, 2025

Tales of Cotton Insects: Monday July 21, 2025

Overall, although the crop is LATE is looks pretty good in most places. Cotton that was planted on time looks like it has very good potential. Widespread rains have slowed down, but we are starting to deal more with random. Pop-up showers. While this is good for the crop, it complicates insect control. We have started getting questions about the rainfastness of insecticides. Unfortunately, there is no one-size-fits-all for this question.

Things to consider:

1. How much time occurred between the rain and the spray? For most products, more time is better. Most products are probably “good” at 4 hours, but 6 is better. Note: acephate is the least rainfast material and needs a minimum of 8 hours with 12 hours being better.

2. How hard did it rain and how much fell? More rain will have a greater impact than less rain. A hard, driving rain will probably be worse than a slower, steady rain. In other words, a half inch in 30 minutes will probably be worse than a half inch in 3 hours.

3. What type of insecticide was used? Systemic insecticides will probably not be impacted as bad as contact insecticides. Most systemics need between 2-4 hours to move into the plant. However, most of our “bug materials” tend to be contact. Although most contact insecticides are not very rainfast, insects can come into contact with them quickly and have enough exposure to die within a few hours of the application. Formulation type is another consideration. Generally speaking, dry materials (e.g. Acephate, Transform) are more susceptible to wash-off than liquid materials (e.g. bifenthrin, Bidrin).

4. What is the target insect? Mobile insects, like adult stink bugs, are more likely to quickly come into contact with insecticides. Insects that tend to stay in more protected areas, like plant bug nymphs hidden behind square bracts, are less likely. Thus, residual is more important if the insects move less.

5. Was an adjuvant used? Adjuvants may help in some cases, but they are unlikely to “fix” the issue with a material like acephate that already has poor rainfastness.

With all this being said, whether to wait on a treatment or to try to beat a rain can be complicated and probably made on field-to-field basis. How much rain is predicted, how long after the rain can the sprayer get across the field and how high the insect pressure is should all be considered. For example, stink bugs are not difficult to control, so maybe waiting the rain out is an option. However, if high populations of immature plant bugs are present, I would consider treating before the rain and risk a wash off with partial control than risk not being able to treat for a week if I don’t have access to a plane and the field is too wet.

Tarnished plant bug nymph (left) vs clouded plant bug nymph (right).

Cotton Insects: Plant bugs are becoming more consistent in fields across the state with clouded plant bugs (CPB) making up a higher percentage of the population than usual. For cotton in bloom, scouting for plant bugs is best with black drop cloths. While this is time consuming and laborious, it is the best way to find immature plant bugs. Other ways are to look for dirty squares and dirty blooms as incidences of plant bug feeding. Threshold is an average of 3 tarnished bugs per 5 row feet. Clouded plant bugs should be counted at 1.5 tarnished plant bugs. In other words, a threshold of CPB only would be 2 per 5 row feet. This is because CPB cause a little more damage than tarnished plant bugs. Also, CPB prefer to feed on small (thumb-sized) bolls. Observations from scouts and consultants last year suggest that organophosphates (Bidrin, Orthene) provided better control than pyrethroids for CPB. We covered insecticide selection for tarnished plant bugs in our last post (link).

Thumb-sized bolls are the preferred feeding site of CPB.

A lot of our early planted cotton is squarely in the stink bug window. We have received reports and made observations of internal boll damage (IBD) rising in fields across Alabama. Threshold during peak bloom (weeks 3-6) is 10% internal damage of 10-12 day old bolls (1 inch diameter, about the size of a quarter). Sample 20-25 bolls across a field and look for signs of feeding. Timely applications of pyrethroids or organophosphates can greatly reduce IBD counts.

Soybean Insects: Overall, soybeans have been quiet this year, but we have started getting reports of defoliators in fields. We have received scattered reports of soybean loopers but none reaching threshold yet. For now, our focus should be on stink bugs in soybeans beginning to fill pods (R4-R5). Threshold is 4 stink bugs per 25 sweeps.

Tuesday, July 1, 2025

Tales of Cotton Insects: Tuesday, July 1, 2025

Early candle stage square with signs of plant bug feeding.

Over the past week, we have received reports of plant bugs in older cotton fields across the whole state of Alabama. The traditional movement of insects seems to be off this year. Wet, relatively cool and cloudy conditions for a lot of June have caused to not grow off as quick as usual and has seemed to keep insects in weedy hosts for the most part. Plant bugs have been trickling into fields and have or are now requiring action. Our plan of attack hasn’t changed since our last blog of adult plant bugs (link). However, we are approaching the time that immatures will begin showing up.

As we get to bloom and target immatures, we must change the plan. Transform (1.75 oz) is an excellent material for control of nymphs. Additionally, acephate (0.75 lb) provides consistent control. Bidrin (6 oz) comes back into play when cotton reaches the first week of bloom. Pyrethroids provide adequate control on some areas but we are increasingly seeing slippage of control and outright failures in some areas. Regardless of the knockdown insecticide used, Diamond (6-9 oz) plays an important role in control. We generally expect 2-3 weeks of residual suppression from Diamond at the 6-9 oz rate, respectively. Note that this is suppression and not knockdown. Diamond is best utilized when applied at the first appearance of nymphs (which will likely happen some where between 10-14 days after an adult application was made). Diamond is an important piece of the plant but management puzzle, particularly with all the rain and pop up showers we have experienced recently.

We also have some fields at peak bloom that are highly susceptible to stink bugs. Populations seemed light in corn this year but that does not mean we can forget about them. As cotton reaches the 3rd-6th weeks or bloom, threshold is just 10% internal boll injury on quarter-sized (~1 in diameter bolls). Pyrethroids and organophosphates provide good control.

Finally in cotton, we have seen some heavy infestations of aphids in many fields. The fungus may be starting to build so applications solely for aphids may not be warranted. However, most plant bug materials provide good control of aphids.

Soybean update. We have received reports and observed fields with redbanded stink bugs in central Alabama. Adults can be killed with high labeled rates of pyrethroids but immatures are a different story. In order to get adequate control, 2 way tank-mixtures of pyrethroids (highest rate), acephate (0.5 lbs) or imidacloprid (highest rate) are needed. Threshold for RBSB is 4 per 25 sweeps (lower than the traditional stink bug threshold =6 per 25 sweeps). If a complex is found, RBSB should be counted as 1.5 of other sink bug species.

Monday, June 16, 2025

Tales of Cotton Insects: Monday June 16, 2025

Overall, the cotton insect situation has been quiet this year., which is not unexpected considering how planting season went. Acres will be down significantly this year, how much? We will have to wait to see. Hopefully we will quickly turn into a “normal” summer pattern with scattered (and hopefully timely) storms for the rest of the year.

For the first time in my career, I am getting calls about thrips and plant bugs at the same time (and on top of that, plant bug calls are later than usual too). Plant bugs have been sporadic with most reports being that few are detected in fields. However, we have also received reports of populations well above threshold and square retention in the 65% range. This highlights the importance of scouting and not guessing where plant bugs are (or are not).

This year, as much as any, we cannot afford to allow square retention to fall below threshold, but we also need to manage plant bugs as economically (cheap) as possible. However, achieving adequate control is still our primary goal. Remember, the best way to maximize the return on an insecticide application is to apply it ON TIME. The only way to do this is to scout fields and follow economic thresholds. In pre-bloom cotton, threshold is 8 adult plant bugs per 100 sweeps AND to maintain 80% square retention (note: in late planted cotton, we may want to be more aggressive on square retention to promote earliness).

With that in mind, we have a few options for control of adults in pre-bloom cotton:

1. Imidacloprid: Many trade names. Imidacloprid is the most economical option we have for plant bug control. While imidacloprid does not provide 100% control (closer to 60-65%) at the highest labeled rates, it generally provides enough to get populations under threshold and preserves square retention

2. Thiamethoxam: Centric, Hub WDG. Thiamethoxam is another neonicotinoid that provides good control of adult plant bugs. Our general recommendation is 2 oz/A. While a little more costly than imidacloprid, this material provides better control. Another option is Endigo ZCX, which is a premix of Centric (thiamethoxam) and lambda-cy. Endigo ZCX at 3.5 oz/A provides the equivalent rate of Centric (2 oz/A) and lambda-cy (1.5 oz/A). While the added lambda-cy may be more likely to flare mites, this pre-mix may be a little more economical than Centric alone.

3. Sulfoxaflor: Transform (1.5 oz/A) provides the best control of plant bugs of all currently registered materials. For that reason, we like to wait to use it when immature plant bugs are present. Waiting for Transform can help to delay resistance and manage adults more economically.

4. Other options: Acephate (0.5 lb) or pyrethroids (highest labeled rate) are options for adults but are not generally recommended. The reason for this is multi-fold. 1. Resistance management. We prefer to use neonics (imidacloprid or thiamethoxam) on adults and then switch to the “harder” chemicals (Ops/pyrethroids) after bloom when targeting immature plant bugs and/or stink bugs. 2. These classes of chemicals tend to be harsher on beneficials, which could lead to outbreaks of spider mite (however, we can and have flared spider mites with neonics sprayed on 7-day intervals). 3. Aphids, while neonics are generally good on aphids, OPs and pyrethroids are not as reliable.

**Note: Pyrethroid resistance has been documented in NW and SW Alabama in recent years. Pyrethroids should be monitored closely for efficacy if used in all cotton growing regions of Alabama.

Complications with adult plant bug management: Adults can continue to move into fields over several weeks as weedy hosts slow play out in wet springs. We suspect this could be the case this year. This may mean we need to spray in consecutive weeks to keep populations below threshold. In these situations, monitoring 1^st position square retention on the upper 2-3 nodes is critical. This is really the only way to determine the efficacy of a spray for adults. Since a cotton plant puts on a new node every ≈3 days, we are evaluating new growth the week following an application. As long as square retention is high (>80%), our spray did its job regardless of adult plant bug numbers.

We have also received scattered reports of aphids across the state. In most cases, populations were just high enough to be noticed, but in a few there were enough to piggyback a shot with a trip for PGRs. Generally, we do not see yield benefits to spraying aphids but it can happen. I suspect this year they may have the potential to slow the crop down, particularly if we get dry. Hopefully all the excess moisture we currently have will play in our favor and help the aphid fungus develop a little quicker than normal.

Thursday, June 5, 2025

Tales of Cotton Insects: June 5, 2025

There has been little action as far as insect across the state in the last couple weeks. The biggest issue has been excessive rainfall – either drowning out stands or preventing planting. With another round of storms moving through this weekend, we are hoping it will be the last and that storms will be spotty instead of widespread.

The Extension cotton team has been putting out information on how to manage late planted cotton. The plan of attack will change as you move from south to north. At the end of the day, the decision will have to come down to a farm-to-farm decision. Consider the economics of reduced yield for cotton compared to planting soybeans or leaving the ground fallow and make the best decision possible.

Below are a few tips on managing late cotton:

1. Plant the shortest season variety available. Earlier maturing varieties (early or early-mid) typically set and mature bolls in a shorter time than full to mid-season varieties.

2. If planting about June 7 or 8 through the 15, plan for a yield goal of 850 pounds (North Alabama). Manage the crop with this goal in mind. If that yield goal does not at least break even, consider the economics of other crops, like soybeans.

3. Reduce nitrogen rates. A crop with a goal of 850 pounds does not need the same inputs as a crop with 1,250-pound potential.

4. Consider reducing seeding rates. Planting late in the window generally means better conditions and a better stand, thus lower seeding rates (approximately 2.5 seed per foot) should provide the needed yield potential.

5. Manage plant bugs aggressively pre-bloom. While the normal threshold is to maintain 80% of the first position squares during the squaring season, farmers cannot afford to lose any squares in late planted cotton. High square set promotes earliness and is critical to achieve this goal. Be prepared to need more plant bug applications than normal in a late crop.

6. Make timely applications of plant growth regulators (PGR) as needed throughout the season. PGR strategies in particular may need to be adjusted but reaction should be made quickly when needed.

7. Make timely insecticide applications as needed. Since there is a short window to set the crop, growers cannot allow insects to delay maturity or cause boll loss. During the blooming window, thresholds may not need to be changed if growers are able to make timely applications. In situations where timeliness is not achievable, thresholds may be reduced to lower the chances of loss.

For more details and in-depth discussion, listen to the most recent episode of the Alabama Crops Report Podcast (link) where members of the cotton team across the state provide insights and information on the current situation.

Thursday, May 8, 2025

Tales of Cotton Insects: May 8, 2025

We have gotten a lot of calls over the past couple of days on grasshoppers across central and south Alabama. It can be tricky to tell how many are adults or immatures, and most folks don’t carry sweep net in seedling cotton to catch them, but at this point it is safe to assume that a decent percentage of the population is adults. Unfortunately, we do not have good thresholds for grasshoppers. It basically comes down to the level of risk a farmer is willing to take. One thing we have noticed is that fields that grasshoppers have reduced stands in in years past are likely to have it happen again. In some conversations, the grower is willing to accept some risk, but in most cases, they are not.

We are pretty limited with options for control of adult grasshoppers. Acephate (0.67 lbs ai) has been the standard and most consistent option. While some people have asked about pyrethroids, they are just too inconsistent on adults. We have also been asked about Bidrin. While we have not tested it, it would likely provide similar control as acephate as both are organophosphates. The labeled rate for Bidrin on grasshoppers is 3.2 oz.

Thankfully, immature grasshoppers are not as difficult to control. The acephate provides good knockdown control, but short residual. This is why we recommend Dimilin (2 oz) be added to the tank. Dimilin provides good residual control of immatures continuing to hatch in the field.

A few other points: Grasshoppers are not a “border pest.” Eggs are deposited in tubes in soil in the fall and are distributed across the field. Thus, the entire field should be treated, not just the borders. Cotton is most susceptible in the crook stage as the emerging stem is just cracking the soil surface. However, stand loss can be threatened after full emergence as grasshoppers feed on the mainstems.

Cotton seedlings damaged by grasshoppers

Development of immature grasshoppers as they age

Adult grasshoppers (note wings)