Friday, August 13, 2021

Alabama Cotton Insect Situation August 13, 2021

As the calendar turns to August the Alabama Cotton Insect Situation has really started to heat up. Plant bugs are still heavy in spots statewide, but stink bugs are becoming more and more of an issue as the crop continues to bloom. Some heavy bollworm egg lays have also been reported in parts of the Tennessee Valley. The overarching theme with many of these pests appears to be the drawn-out planting of corn due to wet weather this spring. Insect pests continue to trickle out of corn as the migrate into cotton fields. Spider mites are also in fields and have reached treatment levels over the past few days as well.

Plant Bugs

Plant bugs (tarnished and clouded) are still requiring treatments in some fields in Central and South Alabama. Cotton in the Tennessee Valley is under pretty substantial plant bug pressure. As we are now blooming, the black drop cloth is the preferred method to scout for plant bugs. Threshold is 3 tarnished plant bugs per 5 row feet. If clouded plant bugs are found, they should be counted as 1.5 tarnished plant bugs. Keep in mind that clouded plant bugs tend to do a little more damage to small bolls than tarnished plant bugs, thus the change in threshold.

Immature Clouded Plant Bug
Immature Tarnished Plant Bug















Stink Bugs

Adult Green Stink Bug
Thus far, stink bug pressure seems to be higher than normal. This is especially true in the Tennessee Valley. In fields where no controls with activity on stink bugs have been sprayed, stink bug pressure (and damage) has been quite high. Stink bugs are a consistent threat to cotton in central and south Alabama, so more controls with activity are used to stink bugs are used when spraying plant bugs. The most reliable method to scout for stink bugs is to sample bolls about 1 inch in diameter for internal sings of injury (pin-prick marks, warts or stained lint). Threshold is 10% internal injury from weeks 3-6 of bloom. Regardless of location in the state, if a “hard” chemistry has not been used by the 3rd week of bloom, I would highly recommend finding a reason to use one.

Bollworms

We received reports of heavy egg lays in the TN Valley this week. No reports of escaped worms have been made (yet), but with 20%+ egg infested plants, there is a possibility. Outside of 2017, escaped worms have not been a big issue in Alabama but there can always be some fields that don’t go as planned. Aside from the terminals, bollworm moths seem to prefer to lay eggs on bloom tags (drying bloom petals). Thus, egg scouting efforts should be focused on in the terminals and the blooming zone (particularly on bloom tags). Currently, our recommended thresholds are based on the number of escaped worms found per 100 plants. Escaped worms may be found on bolls (often underneath the bloom tag), squares or white blooms. In Bollgard II and TwinLink technologies, escaped worms tend to be found in the blooming zone. Threshold is 5 worms (0.25 inches or bigger) per 100 plants. To date, we have seen no issues with 3 gene technologies (Bollgard 3, Widstrike 3, TwinLink Plus). We do not recommend treatment on these varieties.

Bollworm eggs on terminal.
Escaped worm feeding under
bloom tag.

Spider Mites

We have received reports of spider mites from the Wiregrass over the past week. Mites are in nearly every field statewide  at some level all year long waiting for a hot, dry stretch to “blow up.” As we write this, we don’t know what the incoming tropical storm system is going to do, but it looks likely rain events are coming. We do not know what that will do to spider mites approaching treatment levels currently, so making applications in front of the storm may be advisable. Treatment decisions require a bit of professional judgment. Threshold is when mites and their injury is widely distributed across the field. Coverage is critical for control of spider mites. Using the higher end of labeled rates is advisable as cotton is into bloom.

Parting Shots

We still have another 4-6 weeks left to make cotton in Alabama. Hopefully Tropical Storm Fred will bring some needed rain (but not too much). Keep scouting and spraying fields as needed. Up-to-date thresholds and insecticide recommendations visit the Alabama Cotton IPM Guide (IPM-0415). We will continue to put out information through twitter, this newsletter and the Alabama Crops Report Newsletter, Podcast and on the Pest Patrol Hotline. As always, if we can ever be of any help please don’t hesitate to let reach out.


Monday, July 12, 2021

Alabama Cotton Insect Situation July 12, 2021

 Tarnished Plant Bugs

Immature Tarnished Plant Bug
While the peak migration of tarnished plant bugs in central and south Alabama seems to be over, it appears to just be starting in the Tennessee Valley. We received reports and saw fields with 1-3x threshold populations (2 per 25 sweeps) of adult tarnished plant bugs last week (July 7). In almost every case, square retention was still high, which tells us that the plant bugs had just started moving in. As this newsletter is coming out, we suspect square retention will have significantly fallen if those fields were not treated. With the delays in finishing planting and differences in cotton maturity across the state, we will likely be managing plant bugs differently in individual fields this year.

In our most mature fields (those in bloom) we need to be sampling for immature plant bugs. This is done by placing a black drop cloth between two rows of cotton and shaking the vigorously the plants on either side of the cloth to dislodge any insects on the plants onto the cloth. Count the number of immature plant bugs on each sample. Threshold is when you find an average of 3 bugs per 5 row feet (one drop cloth sample).

Adult Tarnished Plant Bug
In our later planted cotton (prior to bloom), we are still looking for adult plant bugs migrating in. To scout for adults, the most efficient methods are to use a sweep-net and/or monitor square retention. To monitor square retention, look for the presence (or absence) of first position squares on the upper 2 or 3 nodes of the canopy. Threshold is when you find an average of 2 adults per 25 sweeps OR if square retention falls below 80%.  One thing to keep in mind when dealing with adult plant bugs is that NO product will provide much, if any, residual control. Adults may continue to infest fields after sprays, so if checking a field 7 days after an application, it may be possible to find the same number – or more – adult plant bugs than the previous week. This does not necessarily mean a control failure, just that more adults have moved into the field. As long as we are setting squares and square retention is above 80% then we know our application did its job.

Depending on the targeted populations, we have several options for control of plant bugs. When going after adults in pre-bloom cotton, the neonicotinoids provide adequate control of both plant bugs and aphids (e.g. imidacloprid, Centric). When primarily dealing with immature plant bugs in blooming cotton, we tend to shift away from the neonics to other chemistries. The insect growth regulator, Diamond, is a good option that provides 2-3 weeks residual control when used at a rate of 6-9 oz, respectively. Diamond should be combined with a knockdown insecticide such as Transform, acephate, Bidrin or pyrethroids (depending on resistance levels in your area) to provide more immediate control.

Stink Bugs

Smaller boll damaged
by stink bugs
As some of our most mature fields are at the first couple of weeks of bloom, it is time to start thinking about stink bugs as well. We know that stink bugs are seed feeders and prefer bolls that are around 10 days old (about the diameter of a quarter), however in a situation with few of these bolls present, stink bugs will feed on even smaller bolls. Don’t slack up on sampling bolls for damage in these earliest fields. Remember that sweep-nets and drop cloths are not an effective way to scout for stink bugs. In order to scout for stink bugs we have to sample for internal boll damage by cracking bolls open and looking for signs of stink bug feeding (warts, pin-prick marks, stained lint). The threshold during the first two weeks of bloom is 30-50% internal damage and 10% for weeks 3-6. In a “normal” year, we don’t worry as much about damage during the first 2 weeks of bloom, because there are fewer bolls at risk during this time. However, this year with fewer acres in the area blooming and setting bolls at this point, we have the same number of stink bugs with less acres of cotton to dilute the population. Thus, stink bugs may be in more concentrated numbers in fields in our most mature cotton than “normal” this year. Be sure to look at small bolls during this time while still scouting for plant bugs. Stink bugs tend to infest field borders (50 feet) and smaller fields (20 acres) more heavily so keep that in mind when scouting.

Aphids and Spider Mites

We have received reports of the aphid fungus killing aphids in parts of South Alabama over the past week. Hopefully the fungus will spread statewide quickly and knockout any lingering populations we are dealing with from now on. We have also gotten reports of spider mites in fields in the east central and southeast areas of the state. For now, we are advising folks to watch the populations and wait until the forecast shows a several of hot, dry days in a row before spraying. We want to maximize the effectiveness of the application and reduce the chances of a rain event reducing efficacy.

Take Home Message for the Current Cotton Insect Situation

With the varying stages of cotton (from 1st true leaf to 3rd week of bloom) across the state (and within an individual farm in some cases) we are going to have to do a lot of insect management on a field-to-field basis in 2021. Proper scouting and keying in on the correct pest for the stage of crop and time of year will be critical. We will continue to put out information through twitter, this newsletter and the Alabama Crops Report Newsletter, Podcast and on the Pest Patrol Hotline. As always, if we can ever be of any help please don’t hesitate to let reach out.

Wednesday, June 16, 2021

Tarnished Plant Bugs on the Move in Alabama

Over the past few days, we have been hearing reports and have seen infestations of tarnished plant bugs 
infesting cotton fields across Alabama, from the Florida line, through central Alabama up to the Tennessee Valley. In some cases, cotton is older (up to 12 nodes) but in many fields the cotton is just starting to put on pinhead squares (7-8 nodes). The one thing all of the fields have in common is that is the most mature cotton in the area. These are the fields we need to be keying in on when scouting. It will be important to scout with a sweep-net (TH= 2 adults per 25 sweeps) and monitor pinhead square retention in the upper 2-3 nodes (maintain 80% of first position squares). Depending on timing, we may see high plant bug numbers and good square retention. However, this could likely be because plant bugs had just moved in and squares that have been fed on have not yet had time to show symptoms. Thus, if either threshold hits, action should be taken. Keep in mind that thresholds aren’t always a “cut and dried” number. If the sprayer won’t be back in an area for 7-10 days and square retention is approaching (but above) 80% with plant bugs present, treatment may be warranted. Sometimes making the call requires some professional judgement based on previous experiences. We filmed a video with more info on plant bugs with Eddie McGriff last year (link).


Based on our sampling of wild hosts (daisy fleabane),
it is likely that we see an extended migration of adult plant bugs over the next few weeks. This gives us the potential to need multiple applications to control adult plant bugs pre-bloom. If this is the case, it will be even more important to monitor square retention. Sometimes following up on an insecticide application can be tricky. We may scout a field 7 days after treatment only to find the same number of (or more) adult plant bugs in the field. This may not mean treatment failure, but that more bugs have migrated into the field. By monitoring square retention, we can check to see that the pinhead squares present at application were protected by the treatment.

Another thing to consider is that the adult plant bugs are also lay eggs and immature plant bugs will start showing up just prior to or at first bloom. Action taken on this migrating population of adult plant bugs can help to reduce future populations of immature plant bugs later in the year.

With good cotton prices and an already late crop, we need to be sure we are staying ahead of insect issues and avoiding any more delays in maturity or losses yield.

If anyone has any observations of plant bugs or any other pests infesting fields, please let myself (662-809-3368) or Ron (334-332-9501) know. We are always here to help.

Thursday, March 4, 2021

Thrips Management in Cotton for 2021

As the 2021 cotton production season approaches, it is time to start preparing for thrips management.

Thrips are the dominate insect pest of seedling cotton in Alabama. Each year, thrips infest 100% of the acres planted statewide. Due to this, thrips must be managed with an at-plant insecticide. We have several options for at-plant management including insecticide seed treatments (ISTs), and in-furrow liquid or granular materials. There are pro’s and cons of each approach, so deciding which strategy to use may make sense for one situation and not for another.

Insecticide Seed Treatments 

In recent years, the neonicotinoid insecticide seed treatments have begun to show reduced efficacy, particularly thiamethoxam. For this reason, we no longer recommend the use of thiamethoxam alone (e.g. Cruiser, Avicta) to manage thrips in cotton. If an IST is used, we recommend it be imidacloprid based. Examples of imidacloprid based ISTs include Gaucho and Aeris (imid. + thiodicarb). Although not bullet proof in all cases, these products typically provide adequate protection from thrips under light to moderate pressure. Another option would be to treat seed with acephate (e.g. Orthene) or to supplement an imidacloprid IST with an additional treatment of acephate. The only problem with this approach is that one a bag of cotton seed is opened and over-treated, it cannot be returned if not planted in most cases.


In-Furrow Insecticides

Another option is to use in-furrow insecticides to supplement or replace ISTs. In-furrow liquid applications of imidacloprid generally provide very good control of thrips. Acephate may also be used and provides good control under the right conditions. Acephate should not be used in place of an IST as it does not provide long residual control and may be leached out of the rootzone prior to plant uptake under cool, wet conditions. Another option is AgLogic (aldicarb). This granular product provides excellent control of thrips and can also be used to manage nematodes as well.

Foliar Insecticides

Foliar insecticide applications should be made to supplement at-plant thrips management, not be used as the “first line of defense.” Cotton is susceptible to thrips injury until around the 5th true leaf stage. Generally foliar applications are most effective when made at the 1-2 true leaf stage. The Thrips Infestation Predictor for Cotton can be used to show the relative risk of thrips injury for cotton planted at a given location and date. This can be used to help plan out fields or planting dates for cotton that will likely need a foliar application. Several options are available to use to supplement at-plant insecticides.

·         Acephate (4-6 oz/A) is an effective and relatively inexpensive option, however it has the potential to flare secondary pests such as spider mites and is the least rainfast of the available recommended options.

·         Bidrin (3.2 oz/A) is another option that is effective and less likely to flare spider mites and is more rainfast than acephate, however it is more likely to cause crop injury when tank-mixed with herbicides.

·         Dimethoate (6.4 oz/A) is another cost effective and efficacious product with good rainfastness, however it is the most likely to cause crop injury when tank-mixed with herbicides.

·         Intrepid Edge (3 oz/A) is another effective option. Intrepid Edge is less likely to flare secondary pests but may need the addition of a surfactant to help with efficacy.

·         Pyrethroids are not effective and should not be used to manage thrips.

In order to get the 2021 cotton crop off to the best start possible, at-plant thrips management is a must. Supplemental foliar sprays may be necessary in certain situations, particularly with earlier planted cotton when nighttime temperatures are cool. More information about thrips can be found in Pests of Alabama Cotton: Thrips (ANR-2718). For more information on thresholds and insecticide recommendations, visit the Alabama Cotton IPM Guide (IPM-0415). Results from 2020 cotton insect research trials can be found in 2020 IPM Projects Advancing Alabama Cotton Production (ANR-2735).

Thursday, February 4, 2021

Looking Back as a Career Winds Down: 50 Years of Cotton IPM in Alabama (1971-2021)

 

I began my career as an Extension entomologist at Auburn University on April 24, 1972. To put that into perspective – Richard Nixon was president and the Vietnam War was still ongoing. I have worked under the direction of eight Alabama Cooperative Extension Directors and numerous Deans of the Ag School/Experiment Station.

It has been quite a journey to have been a part of the most evolutionary period ever in cotton insects. I began my career when boll weevils were the key and dominant cotton insect in Alabama and as part of the new USDA-Extension cotton IPM educational initiative. Each cotton producing state received new federal funding to add one additional cotton entomologist. Two states, North Carolina and Arizona, added an additional entomologist a year earlier, in 1971. In 1976, this increased educational program had proven so successful that additional funding was provided that enabled the Alabama Cooperative Extension Service to add two additional area entomologists (Decatur and Selma) and four multi-county IPM agents (three in the Tennessee Valley, where a high percentage of the cotton acreage was at that time, and one in central Alabama). The special funding for this program effort continued for more than 30 years. The goal of this new program was to increase the awareness of a management approach to controlling cotton pests. 

The Extension cotton scouting program and use of economic thresholds, which forms the basis of a management approach, was initiated by Drs. Walter Grimes and Roy Ledbetter with the aid of Mr. Frank McQueen (survey entomologist) in the late 1950’s and early 1960’s. During the early to mid 1970’s our primary cotton insecticide tool was the organophosphate class of chemistry. The organophosphates, such as methyl parathion and Guthion, were characterized by fast acting activity but short residual. In addition, most chemicals in this class had acute human and mammalian toxicity. The phosphate chemistry had excellent activity on the boll weevil but brought on resistance in the tobacco budworm and secondary pests such as spider mites and whiteflies. The heavy use of phosphate insecticides also caused major problems with delayed maturity of the crop. This problem with delayed maturity was so pronounced that a special session was added to the Beltwide Cotton Research and Control Conference in January of 1976. Another type of insect control tool, that many of today’s growers do not remember, was available during the 1972-1989 window. This tool was the ovicide (worm egg only) chemical chlordimeform, sold as Galecron and Fundal. This chemical impacted cotton IPM scouting programs by creating a need to change to twice per week field monitoring (scouting). The life stage of a bollworm or tobacco budworm egg was only three days, so the increased egg counts had to be detected and targeted with an ovicide within a three day window when egg numbers peaked.

In 1976, the pyrethroid class of chemistry became available, first under an EPA issued emergency use permit (EUP). In 1978, pyrethroid insecticides received full but conditional registration and became the major player in cotton insect control for the next decade. For a few years, pyrethroids were highly effective on most all cotton insects. Insect losses were very low, yields reached a new higher plateau, and maturity issues disappeared. Due to extended residual from the pyrethroid insecticides (Ambush, Pounce, and Pydrin) application intervals for the boll weevil could be extended from 5 to 7 days. However, during the decade of the 1980’s, depending on the area of the Cotton Belt, tobacco budworms became resistant to the pyrethroid class of chemistry.

It was during this time period that the final plan to eradicate the boll weevil was being developed. This program had been under development for more than a decade. One of the big driving forces to eradicate the weevil was the possibility that boll weevils might develop resistance to the organophosphate class of chemistry. This possibility would have wrecked the cotton industry in the U.S. Pyrethroids had activity on the weevil but were not as effective as the phosphates and were initially significantly more expensive. The boll weevil never developed resistance to the phosphates, in fact, the phosphate insecticide malathion was the primary insecticide used for eradication.

In the Fall of 1986, the organized boll weevil eradication initiative reached Alabama. This program was first started in northeastern N.C. (Chowan Co.) a few years earlier. Twenty-one counties in southern Alabama were included in the first eradication zone. During the following 7 years the program was expanded throughout the remainder of the state (central AL – 1992, NE AL – 1993, and TN Valley – 1994). By the summer of 1995 no economic losses to the boll weevil could be found anywhere in the state.

During the active eradication program period (1986-1995), insecticide resistant tobacco budworms and impossible to control beet armyworms caused yield losses beyond anything ever observed or previously recorded. During one season, yield losses to beet armyworms alone were estimated to be about $40 million across the state. Pirate, a new highly effective chemistry that was under development by American Cyanamid, was requested for emergency use from the EPA multiple years. However, this request was denied until August of 1995, which proved to be too late to help with the beet armyworm outbreak that had been ongoing since 1987. At the end of the 1995 season the outlook for the future of cotton production in Alabama was bleak.

Fortunately, genetically altered Bt (Bollgard) cotton varieties, which had been under development and evaluated in select fields for the previous four seasons, became available to growers. This new technology was readily adopted by Alabama growers and 77% of the 1996 acreage was planted to Monsanto Bollgard varieties. This rapid adoption was primarily in self-defense following the heavy losses to worms the previous years. However, planting this new technology brought with it rules and regulations never experienced before by growers. Word was spoken that growers would never have to treat for worms again. This proved to be incorrect when in late July 1996 news of bollworm escapes in the Brazos River area of central Texas spread across the Cotton Belt. It was only about one week later when this escape bollworm and fall armyworm problem was observed in Baldwin Co., Alabama. Some growers wanted to give up on this new technology immediately. However, over the following years entomologists and growers learned more about what to expect form Bollgard cotton varieties and how to manage these escape bollworms, which could be controlled with a minimum of well-timed pyrethroid sprays. The following 10 years proved to be good for growers with overall improved yields and minimal insect losses and control costs.

It was during this low spray environment that the bug complex became more damaging to yields. In north Alabama it was the tarnished plant bug that had to be monitored and managed more closely. In central and south Alabama, as well as the remainder of the Coastal Plains of the southeastern U.S., it was the stink bug that became the dominant economic insect of cotton. Entomologists in the Carolinas, where the weevil was first eradicated, had reported that stink bug damage increased. However, populations of the southern green stink bug in the southeastern U.S. caused even greater damage than did the green stink bug species in the Carolinas. It took several years for growers and fieldmen to realize how devastating the stink bug could really be.

By the time better stink bug management was adopted, the Bollgard technology, with one Bt gene, began to lose its effectiveness and escape bollworms were more widespread . Experts had warned that this phenomenon would happen since the single Bt gene was never 100% effective on the bollworm species, as it was on the tobacco budworm. Anticipating this, Monsanto had begun work on stacking a second gene. This second Bt gene entered the market in 2009 and reduced this escape bollworm problem by about 90%, followed by Bollgard III in 2018. WideStrike genes from DOW AgroSciences (Phytogen varieties) first became available in 2005 and were followed by the third gene (WideStrike3) in 2014.

Cotton insect control overall from 1996 to 2020 has been good with no boll weevils or tobacco budworms and minimal escape bollworms in the system. However, sucking pests such as thrips, aphids, whiteflies (silverleaf) and spider mites have required monitoring and management. In addition, due to reduced tillage trends, certain sporadic or new pests have had to be contended with. Some of these are grasshoppers, cutworms, snails, slugs, and early season spider mites. However overall, the past two decades have required careful monitoring and selective management and control skills, but insect losses and control costs have been historically low and have served to keep the cotton industry profitable in Alabama.

The evolution of cotton insect management is so great that fire ants are now considered as the number one beneficial insect against escape bollworms in our reduced tillage system. It is felt by several entomologists that fire ants are playing a big role in allowing Alabama growers to continue to plant two-gene varieties, primarily DP 1646, without the need for costly diamide chemistry (Prevathon and Beseige) oversprays. The diamide chemistry, developed by Dupont, is highly effective when applied timely on most worm species. What would have been a significant development, had it not been for the introduction of genetically modified genes back in 1996, was the introduction (1996-98) of spinosad (Tracer) chemistry by DOW AgroSciences. For the first time since the development of synthetic pesticides in the 1940’s, caterpillar pests could be controlled with this selective chemistry while lady beetles and other beneficial insects were not affected and remained in fields.

More recent years of cotton insect control have been dominated or characterized by the emergence of sucking pests, such as aphids, spider mites, thrips, and whiteflies (silverleaf), and the bug complex (plant bugs, stink bugs, and leaf-footed bugs). As we moved into this reduced foliar spray era following the elimination of the boll weevil and tobacco budworm, our chemical tools became more selective. Our new caterpillar insecticides do not control sucking pests or the bug complex and the sucking pest insecticides do not control the bug complex or escape bollworms. Insecticides targeted for the bug complex give limited control of sucking pests or escape caterpillars. Tank mixes of two or more insecticides are again often necessary. In the 1950’s and 60’s most insecticides were formulated as mixtures at the distribution level. Now, these mixtures are prepared on the farm as the sprayer is being loaded.

The future will likely continue to be dominated by our current conditions. New advances may be limited. Few new chemistries will be developed. Development cost of chemistry cannot be recouped from cotton usage alone, as was done in the earlier years. New chemistry developed today must find market share with all row crops along with vegetables, fruits, nuts, and other grain and food crops. New advances will likely come in the form of genetics. These advances take years of research and development and as many or more regulations as do chemicals. A thrips-lygus gene is nearing the marketplace in 2021. Based on research, this gene may prove most effective on thrips with moderate activity on plant bugs. It will not help on stink bugs, which are likely to continue to be the dominant economic insect in Alabama and the Coastal Plains of the southeastern U.S. Rather than advancing the discipline of row crop and cotton entomology, our future may be described as a “stay ahead of resistance” in the decades ahead. Resistance issues are present today in the following species: thrips, plant bugs, bollworms, spider mites, aphids, and possibly other species. The greatest challenge in entomology today is staying ahead of resistance and managing sporadic pests such as slugs, snails, cutworms, grasshoppers, three-cornered alfalfa hoppers, leaf-footed bugs, and others. Reduced tillage has been a great advancement; however, this practice has created numerous cracks that are being filled by sporadic pests that require the attention of entomologist and fieldmen advisors.

In summary, the past 48 years of cotton production and insect management have evolved in many, and in some instances unexpected, ways. Examples include:

·       The change from intense cultivation to reduced tillage and heavy dependence on herbicides.

·       The development of major resistance issues with weeds and numerous insect species.

·       The development of increased problems with nematodes and, potentially in the future, plant viruses.

·       A shift from boll weevils to the stink bug complex as the most economic insect.

·       The change from phosphate chemistry to the pyrethroids and now the diamide chemistry.

·       The change from 5 day insecticide application schedules for boll weevils to 2 to 4 seasonal foliar sprays.

·       The escalation from nominal seed cost to very expensive seed and trait costs.

·       For most of the past 50 years, growers were using granular insecticides (Disyston, Temik or Thimet) at planting for early season insect control. In more recent years seed treatments, with neonicotinoid class chemistry, followed by foliar sprays were the standard practice for early season pests.

·       The change from moderate expenses per acre spread across the season to high, front-end budget inputs.

·       A shift from a few secondary pests to numerous new sporadic pests.

·       The change from Extension ag agents in every county to a regional agent with responsibilities spread over as many as 15 counties.

·       Early in my career, most Extension specialists had 100% Extension appointments and were not in academic departments at Auburn University. Most all of their research during those years was in the form of on-farm demonstrations. Now most all Extension specialists have split appointments (ex. 75% Extension, 25% research) and have professorial rank in our academic departments. These Extension specialists are conducting a high percentage of applied research on University research farms.

·       The shift from primary information sources of Extension agents/specialists and insecticide distributor salesmen to private consultants and well-trained commercial agrifieldmen.

·       The change from print media to electronic tools.

Entomologists who have been a part of the Alabama cotton pest management team over the past 48 years are: Roy Ledbetter, Frank McQueen, Ron Smith, Richard Davis, Glenn Worley, Barry Freeman, Tim Reed and Aaron Cato (post-doc). On April 1, 2020 Dr. Scott Graham assumed lead responsibility for this program. Dr. Graham is a native of Mississippi and has degrees working under prominent cotton entomologists (M.S. Mississippi State, Ph.D. University of Tennessee). Therefore, the program has great leadership for the future.

What an evolution and what a ride for an Extension entomologist over the past five decades. Always a challenge, always an additional idea on how to educate or have a more positive impact on cotton pest management. Job never complete nor finished, but most rewarding job in the world. Spent a career in trying to help my friends manage their insects. Knees are worn out but the mind is still going. Desire to be involved for a few more years in some capacity. I will end with a thought and a quote from one of my all-time favorite books, “Cotton is the greatest crop heaven ever gave to a country,” Red Hills and Cotton – An Upcountry Memory by Ben Robertson, 1940.

 

Wednesday, August 5, 2020

Cotton Insect Control for Remainder of 2020 Season

In most seasons, we would be entering the home stretch for cotton insect control by early August. While this may be true for fields planted on time in 2020, it is not the case for a lot of late planted, late emerging, late maturing fields this season. I hope we can narrow our focus to just a few species of insects for the remainder of this season. The primary group would be the bug complex (plant bugs, stink bugs, and leaf footed bugs). However, there are several other insects that could arise if weather conditions or other circumstances permit. These are spider mites, late season aphids and especially silverleaf whiteflies.


The insects of focus for the remainder of the 2020 season may not be as concerning as how long our management and control programs should extend into September and even October on our later maturing cotton. Let’s look at some general guidelines. If past seasons give us any trends, our escape bollworm issues should end by Labor Day. However, we should continue our monitoring as long as our late maturing fields have squares in the top of plants that would serve as a food source for a one-day old bollworm. Once all the squares are gone, escape bollworms will have a difficult time becoming established. The bug complex should eventually be dominated by stink bugs here in Alabama. This may consist of several species; the brown, southern green, leaf footed bug, and the brown marmorated (BMSB), which can now be found in many cotton growing counties. How long should we continue stink bug controls on late maturing cotton? Our general rule with our traditional stink bug species is to continue controls until the top bolls we hope to harvest are about 25 days old. When the BMSB is in the mix, we may need to protect even longer since this species will attack bolls from thumb nail size, up until they begin cracking. With our late maturing fields this season, we will need stink bug controls through at least the month of October. An application for stink bugs usually gives us 10-14 days of boll protection. However, as some fields mature out, just like with corn, stink bugs will move to younger cotton, or swag areas of fields that are still producing bolls or to late maturing soybeans. In other words, as our crops mature in September and October we will get field to field and crop to crop movement of stink bugs. As far as insecticide choices—Bidrin, bifenthrin or any other pyrethroid at a high-labelled rate should give adequate control. The best way to scout for stink bugs will be to examine bolls for internal injury. Just observing or using a sweep net or drop cloth for stink bugs is not very effective and often leads to underestimating the number present. 



Monday, July 13, 2020

Thoughts and Tips for Bollworm Scouting on 2 Gene Cotton for 2020


·       If monitoring 2 gene cotton in 2020, take note of the corn planting window in your area. This plays a large role in the emergence and movement of corn earworm (bollworm) moths to cotton in July and August. The more corn planting is spread out, the wider the emergence window of bollworms.

·       Bollworm moth activity is not constant throughout the season. Instead, it occurs in cycles especially through July. By August, generations of bollworms and tobacco budworms overlap. Fieldmen should detect the start of these peaks by focusing on eggs and newly hatched larvae in terminals/white blooms.

·       Scouting intervals for bollworms may be reduced to 3-4 days during critical windows on 2 gene cotton in 2020. Fieldmen could spot check select sentinel fields of similar variety and planting date on alternate visits to detect increased activity.

·       When monitoring for bollworm larvae or eggs on 2 gene cotton in 2020, be more concerned about detecting population increases early, and reacting if necessary, than quantifying exact numbers—for example: 18 vs. 28 per whatever.

·       Fieldmen should consider damaged fruit on 2 gene cotton in 2020, but treatment decisions will be more timely if primary focus is on eggs and/or newly hatched larvae.

·       Based on my observations during the Bt cotton era of the past 20 plus years, escape bollworm larvae do not feed on or damage as many fruiting sites per worm as they did in the pre Bt era.

·       In order to stay on schedule in 2020, fieldmen should consider only staying in a field long enough to make confident treat or not treat decision.

·       Pest Patrol Updates on cotton/soybean insects in Alabama are available again in 2020. To sign up for the Syngenta Pest Patrol Updates for Alabama, register online at https://www.syngenta-us.com/pest-patrol or register via text message by texting pestpat11 to 97063.