What are we currently finding in Alabama cotton fields? Plant bugs, both the tarnished and clouded species, have finally reached threshold or treatment levels in April planted fields that have not been sprayed. Some level of brown stink bugs can also be found in these same fields. A bug clean up spray would be advised for most cotton that is in the fourth or fifth week of bloom. Peak numbers of squares and bolls are currently at risk. Cotton planted after about May 10 missed most of the plant bugs this season. In central and south Alabama, there are very few plant bugs currently present in wild host or other crops. In other words, there are no more plant bugs in the landscape to migrate to cotton in 2017 in that region.
Between July 24 and 28, numerous field people from all areas of the state were contacted about escape bollworms on cotton with caterpillar technology. As of July 31, no none has reported any problems. We have conventional cotton on research stations in several areas of the state. Some level of bollworms and damage can be found on this cotton. The corn earworm flight from corn began about July 15 and has likely already peaked. Tobacco budworms will enter the mix during the month of August, but they will not be part of the "escape" situation in August. However, fieldmen should continue to monitor closely for escape bollworms. In Alabama, I would suggest we try the pyrethroid chemistry first if escapes are found.
Spider mites came into the picture about the third week of July in the Tenn. Valley area. Mites will likely show up in other fields statewide if we ever experience a 7-10 day period between rain events. Abamectin will provide the most economical control of mites. Whiteflies may occur in late season on our late maturing fields. If whiteflies are observed, I would recommend we use pyrethroid chemistry for stink bugs since Bidrin seems to aggravate the whitefly situation.
We will likely see stink bug numbers increase as we move into August and even September in our late maturing cotton. The southern green stink bug will make up a greater part of the population in coming weeks. This gives us the flexibility to choose either pyrethroid or phosphate chemistry. For weeks 3 through 6~7 of bloom, we recommend a 10% internal damage boll threshold for stink bugs.
Thus far in 2017, insects have not been a major limiting factor in Ala cotton production. Let's hope we can keep this trend going for several more weeks.
Showing posts with label tobacco budworm. Show all posts
Showing posts with label tobacco budworm. Show all posts
Monday, July 31, 2017
Friday, February 7, 2014
AL/GA Consultant's Meeting Presentation: The Past and Future of Cotton Insect Management and Control
Below is my power point presentation from the Alabama/Georgia Consultants 2014 Meeting.
Wednesday, September 4, 2013
Final Insect Update of the Season
The Alabama row crop insect control season is rapidly winding
down. The few areas that still need attention for a few more weeks are as
follows. We need to protect bolls on June planted cotton from stink bug injury
until the bolls are approximately 25 days old. We still have plenty of time
left in the season to mature small bolls that are present from blooms the last
week of August. On soybeans, stink bugs continue to reproduce and feed on pods.
Late planted, June to early July, soybeans will be susceptible to stink bug
feeding for several more weeks. Stink bug adults will leave other crops when
they mature and seek out late planted soybeans as their last host before heading
for overwintering sites. I expect to see high numbers of stink bugs in many of
these late maturing soybean fields. The good thing is that one application to
economic levels of stink bugs in both cotton and soybeans made now should hold
populations below damaging levels for the remainder of the season. Stink bug
populations currently contain both the brown and southern green species. A high
rate of most pyrethroids on soybeans should give adequate suppression. Kudzu
bug adults are still present in many soybean fields but they are not as
numerous in most fields as they were back a month or so ago. Their numbers
seemed to have peaked in April and May planted beans back in the late June to
early August window.
Overall 2013 has been a light insect year in Alabama for
most species. A summary of what I have observed is the following. For cotton,
thrips were moderate to heavy. However, their movement from wild hosts to
cotton occurred in May instead of April. Therefore, their damage period
coincided with our mid-planting period cotton instead of the earliest planted
as happens most seasons. Plant bugs, aphids and spider mites were very light
overall. Bollworms and tobacco budworms were low to nonexistent, even in fields
of conventional cotton. I have conventional cotton on three research stations
spread across the central and southern areas of Alabama. One had to search very
hard all season to find a single larva or damaged fruit. Stink bugs were the
only cotton insect that occurred at damaging levels in most fields in-season.
In soybeans, Kudzu bugs were extremely heavy in many early
planted soybean fields. This was the first year that many soybean growers have
had to deal with the Kudzu bug. Others will likely have their first experience
in 2014. When all is said and done, I believe we will be able to handle this
insect with one, or at most two, well timed sprays. Late maturing beans will likely
still see a big buildup of stink bugs in coming weeks as other crops mature and
dry down. The foliage feeding complex of green cloverworms, velvetbean
caterpillars and soybean loopers have been very light in 2013. This follows the
most widespread infestations of the past 40 years last season. Podworms have
been very light in soybeans for the past two seasons.
This has been a very unusual year rainfall wise. This may be
the only season during my 41 years here as our Extension Entomologist where we
had too much rain.
Monday, June 24, 2013
Insect and Crop Update for the Week of June 23
After going weeks with light to moderate thrips pressure,
damage was heavy on 4-7 leaf cotton in early June, especially in SW Alabama.
Cotton was growing rapidly but thrips damage on true leaves was showing heavy damage from about the 4th to 7th true leaf. (Peanuts also were taking heavy damage during this same period.)
The thrips window is over now and we need to shift our focus to spider mites, aphids and the plant bug complex which includes tarnished plant bugs, fleahoppers and an occasional clouded plant bug.
Mites are primarily found in the TN Valley region of North Alabama and some treatments were being applied last week.
I noticed the first aphids on April planted cotton in central Alabama last Friday (June 21).
Plant bug numbers (adults) were down last week but nymphs are beginning to appear in our earliest planted cotton (mid-April). I would suggest using a sweep net to sample adults for the next 2-3 weeks, depending on the age of the cotton. As we approach first bloom I would switch to a drop cloth and concentrate on the presence of immature plant bugs.
Also, field men should now be looking at pinhead square set. Fields surveyed on June 21 were setting about 90% of the fruit. However, some plants had up to 30% square loss at that point. I believe you will find that migrating adult tarnished plant bugs will seek out the earliest planted and most lush cotton fields. My thought is that this cotton provides the best shade from the 95 degree temperatures, and is the best host for plant bugs.
While looking for pinhead square set I noticed a number of white eggs, likely tobacco budworms. They would not be a concern now, but in the old days it would have created a real predicament. Spraying for plant bugs during a budworm moth flight would have been expensive and also put the grower on a treatment treadmill for the remainder of the season. Sometimes we forget how well we have it compared to the pre-Bollgard years.
On another insect – a few stink bugs are already present in cotton. Normally we do not worry about stink bugs until about the third week of bloom, when we have bolls that are 10-12 days old. However, when stink bugs are present at bloom they will attack thumb sized bolls as soon as the bloom tag sheds. Any feeding to bolls this size will cause the boll to abort. Therefore, fieldmen need to be alert for adult stink bugs in early bloom cotton as they monitor for plant bugs with a sweepnet. Stink bugs will not damage squares or blooms but will seek out these first small bolls.
Since some of our corn was planted later than desired, stink bugs will likely remain with that host until the post roasting ear stage when the kernels become hard. At that time we may have a large movement into other crops such as cotton, soybeans and peanuts.
One word about Kudzu bugs on soybeans. Numbers of adults are out of site on many of our April planted beans. In fact, adult numbers are beginning to decrease in some fields now but numerous immatures are present, which is the trigger we use to treat the field. Fieldmen who have not experienced this insect may overlook these immatures when they are small. They will be a clear to greenish color and very small after hatching.
Cotton was growing rapidly but thrips damage on true leaves was showing heavy damage from about the 4th to 7th true leaf. (Peanuts also were taking heavy damage during this same period.)
The thrips window is over now and we need to shift our focus to spider mites, aphids and the plant bug complex which includes tarnished plant bugs, fleahoppers and an occasional clouded plant bug.
Mites are primarily found in the TN Valley region of North Alabama and some treatments were being applied last week.
I noticed the first aphids on April planted cotton in central Alabama last Friday (June 21).
Plant bug numbers (adults) were down last week but nymphs are beginning to appear in our earliest planted cotton (mid-April). I would suggest using a sweep net to sample adults for the next 2-3 weeks, depending on the age of the cotton. As we approach first bloom I would switch to a drop cloth and concentrate on the presence of immature plant bugs.
Also, field men should now be looking at pinhead square set. Fields surveyed on June 21 were setting about 90% of the fruit. However, some plants had up to 30% square loss at that point. I believe you will find that migrating adult tarnished plant bugs will seek out the earliest planted and most lush cotton fields. My thought is that this cotton provides the best shade from the 95 degree temperatures, and is the best host for plant bugs.
While looking for pinhead square set I noticed a number of white eggs, likely tobacco budworms. They would not be a concern now, but in the old days it would have created a real predicament. Spraying for plant bugs during a budworm moth flight would have been expensive and also put the grower on a treatment treadmill for the remainder of the season. Sometimes we forget how well we have it compared to the pre-Bollgard years.
On another insect – a few stink bugs are already present in cotton. Normally we do not worry about stink bugs until about the third week of bloom, when we have bolls that are 10-12 days old. However, when stink bugs are present at bloom they will attack thumb sized bolls as soon as the bloom tag sheds. Any feeding to bolls this size will cause the boll to abort. Therefore, fieldmen need to be alert for adult stink bugs in early bloom cotton as they monitor for plant bugs with a sweepnet. Stink bugs will not damage squares or blooms but will seek out these first small bolls.
Since some of our corn was planted later than desired, stink bugs will likely remain with that host until the post roasting ear stage when the kernels become hard. At that time we may have a large movement into other crops such as cotton, soybeans and peanuts.
One word about Kudzu bugs on soybeans. Numbers of adults are out of site on many of our April planted beans. In fact, adult numbers are beginning to decrease in some fields now but numerous immatures are present, which is the trigger we use to treat the field. Fieldmen who have not experienced this insect may overlook these immatures when they are small. They will be a clear to greenish color and very small after hatching.
Monday, August 6, 2012
Update for the Week of August 5
We are now in the home stretch, as far as insect control, in
most fields of April planted cotton. Overall, there are a few things that I
would be on the outlook for this week.
Stink bugs pose the greatest threat to most fields for the remainder of the season. Numbers vary greatly from field to field and in many cases from area to area within fields. For this reason, surveys must be thorough enough to detect the overall situation in each field. A dozen or so bolls will not accurately reflect the true infestation in most instances. Remember to select or sample 10-12 day old (quarter diameter) bolls. First separate out those with external damage from those with no external feeding signs. Second, crush those bolls with external damage and observe for internal injury. Our recommended “dynamic threshold” ranges from 30-50% internal damage early in the blooming period down to 10% during weeks 3-6 of bloom. This low threshold corresponds to the period when a high percentage of the total bolls are being set. Later into the blooming season, which is where many of our fields are now, we can relax our treatment threshold back up to the 30-50% range.
Now onto some other pests:
The mid-to-late July bollworm flight was maybe the lowest in modern times. Bollworms have been almost non-detectable in fields in central, SW and SE Alabama, even in cotton with no genetic technology.
As to tobacco budworms – while at the Wiregrass Research Center (SE Alabama) last week, numerous TBW moths were observed. This matches up with reports from SW Georgia that indicates an extremely high budworm flight going on in that nearby location. This will not be anything of concern for Bt cotton but this could be a very significant event for peanut growers and even soybeans.
No questions were received concerning spider mite control last week. However, I personally observed mites in numerous fields that have not historically had mite infestations. They are present in many fields and their explosion will be greatly influenced by temperature and moisture for the remainder of the season. Growers treating for stink bugs would be wise to select an insecticide that is least likely to help flare mites.
With these thoughts we will end today and get back with another update as conditions change.
Stink bugs pose the greatest threat to most fields for the remainder of the season. Numbers vary greatly from field to field and in many cases from area to area within fields. For this reason, surveys must be thorough enough to detect the overall situation in each field. A dozen or so bolls will not accurately reflect the true infestation in most instances. Remember to select or sample 10-12 day old (quarter diameter) bolls. First separate out those with external damage from those with no external feeding signs. Second, crush those bolls with external damage and observe for internal injury. Our recommended “dynamic threshold” ranges from 30-50% internal damage early in the blooming period down to 10% during weeks 3-6 of bloom. This low threshold corresponds to the period when a high percentage of the total bolls are being set. Later into the blooming season, which is where many of our fields are now, we can relax our treatment threshold back up to the 30-50% range.
Now onto some other pests:
The mid-to-late July bollworm flight was maybe the lowest in modern times. Bollworms have been almost non-detectable in fields in central, SW and SE Alabama, even in cotton with no genetic technology.
As to tobacco budworms – while at the Wiregrass Research Center (SE Alabama) last week, numerous TBW moths were observed. This matches up with reports from SW Georgia that indicates an extremely high budworm flight going on in that nearby location. This will not be anything of concern for Bt cotton but this could be a very significant event for peanut growers and even soybeans.
No questions were received concerning spider mite control last week. However, I personally observed mites in numerous fields that have not historically had mite infestations. They are present in many fields and their explosion will be greatly influenced by temperature and moisture for the remainder of the season. Growers treating for stink bugs would be wise to select an insecticide that is least likely to help flare mites.
With these thoughts we will end today and get back with another update as conditions change.
Friday, January 20, 2012
Impact of Alabama Cotton Commission Research Support for Cotton Insect Management-30 Year Overview 1986-2011
Thirty years of cotton insect research in Alabama— from boll weevils to boll weevil eradication– to beet armyworms and pyrethroid resistant tobacco budworms– to genetically altered varieties– to boll feeding bugs (stink bugs). On the chemical arsenal side– from Azodrin, EPN + methyl parathion, Lannate, Bolstar, Curacron, Galecron, and Fundal and the original pyrethroids (Ambush, Pounce, and Pydrin) to generics of the third generation pyrethroids.
What an evolution and what a ride. Thanks to support by the Alabama Cotton Commission, we have survived and are better for it.
One could argue that the past 30 years have been the “worst of times and the best of times” in cotton insect control. I consider it to be the most exciting and revolutionary period in cotton insect control history. The worst of times was the period of 1987 to 1995 with uncontrollable beet armyworm outbreaks and the development of pyrethroid resistance to the tobacco budworm. The best of times was made possible by the eradication of the boll weevil and the introduction of genetically altered cotton varieties. The “best of the best” times were experienced by many growers in 2011, with one of the statewide highest yielding years in history, the best market prices in my career and the lowest insect loss year in history. Both Alabama and the U.S. reported total losses to insects in 2011 as 2-3%, the lowest ever recorded.
Two of the most important events in cotton insect control in the past 100 years happened during the past 30 years: boll weevil eradication and the introduction of genetically altered varieties. In 1996, the first year of Bollgard cotton, Alabama lead the cotton belt by planting 77% of our acreage to the new technology. I feel certain that this set a record in the adoption of new technology. This was the result of two factors, one much more significant than the other. The overriding factor was the pressure and damage by the tobacco budworm in 1994 and 1995. A secondary factor was impacted by funding by the ACC which allowed us to work with the Bt technology for four years before it was introduced. We felt very comfortable in recommended Bollgard varieties to growers based on four years of research experience.
Looking back at this 30 year period, we can see where research support by the ACC was involved at every turn and event during this historical period.
Let us look back now at some of the major insect events and advancements that happened during the past 30 years and discuss briefly how ACC projects gave answers to the most significant concerns and questions during this era. I will attempt to present these in chronological order.
A. Beet Armyworm Outbreaks
L. Emergence of Sporatic Pests
The ACC did not fund all of every project completed over the past 20-30 years. However, your support often made it possible to be in a learning situation on insect outbreaks; new emerging pests/problems and on projects/trials that were not directly funded. Some of you may remember that my grants in earlier years were entitled “To look at New Chemistry and Technology and Determine Where They Best Fit in Alabama Cotton Production”. This allowed us to know more about the strengths and weaknesses of new chemistry/technology than even the companies bringing them to the market. Cotton insect research is unlike most of the other disciplines in that it requires much more hands on involvement. Often times, support from multiple sources had to be pooled to provide the labor and travel to conduct cotton insect trials. Fifteen to 20 trips to a research site are often required between planting and harvest. This is especially true with the genetic technology under development.
A final point I would like to make is that we in Extension have conducted basically all the cotton insect research since the early 1990’s without an Ag Research station counterpart. We feel that we have kept Alabama growers up-to-date and often ahead of the curve in cotton insect management, when compared to other states. Much of the credit goes to the support we have received from the Alabama Cotton Commission.
What an evolution and what a ride. Thanks to support by the Alabama Cotton Commission, we have survived and are better for it.
One could argue that the past 30 years have been the “worst of times and the best of times” in cotton insect control. I consider it to be the most exciting and revolutionary period in cotton insect control history. The worst of times was the period of 1987 to 1995 with uncontrollable beet armyworm outbreaks and the development of pyrethroid resistance to the tobacco budworm. The best of times was made possible by the eradication of the boll weevil and the introduction of genetically altered cotton varieties. The “best of the best” times were experienced by many growers in 2011, with one of the statewide highest yielding years in history, the best market prices in my career and the lowest insect loss year in history. Both Alabama and the U.S. reported total losses to insects in 2011 as 2-3%, the lowest ever recorded.
Two of the most important events in cotton insect control in the past 100 years happened during the past 30 years: boll weevil eradication and the introduction of genetically altered varieties. In 1996, the first year of Bollgard cotton, Alabama lead the cotton belt by planting 77% of our acreage to the new technology. I feel certain that this set a record in the adoption of new technology. This was the result of two factors, one much more significant than the other. The overriding factor was the pressure and damage by the tobacco budworm in 1994 and 1995. A secondary factor was impacted by funding by the ACC which allowed us to work with the Bt technology for four years before it was introduced. We felt very comfortable in recommended Bollgard varieties to growers based on four years of research experience.
Looking back at this 30 year period, we can see where research support by the ACC was involved at every turn and event during this historical period.
Let us look back now at some of the major insect events and advancements that happened during the past 30 years and discuss briefly how ACC projects gave answers to the most significant concerns and questions during this era. I will attempt to present these in chronological order.
- No effective chemistry available
- Parasites and predators, if present, gave effective control-- but not possible during active eradication
- Experimental insecticide, Pirate, highly effective but not approved by the EPA for emergency use until too late (August 1995)
- The original efficacy work on BAW control with Pirate was done at Prattville Experimental Field with ACC support
- Meeting with EPA in Senator Heflin’s office- Washington D.C.
- Pyrethroid Resistant Tobacco Budworms
- No effective chemistry available
- 1994-1995 highest numbers in history, up to 5 larvae per plant
- Yield losses astronomical
- ACC funded research showed that a combination of Lannate + Larvin on 5-7 day schedule gave suppression
C. Transition from In-furrow to Seed Treatments for Thrips Control
- Grower adoption rapid due to convenience and safety
- Initially Cruiser and Gaucho
- Transition to complete-pak with nematode suppression, Avicta and Aeris
- ACC research showed that seed treatments were not as consistent as in-furrow, and often needed a supplemental foliar spray, especially if planting in the early season window. Also, that seed treatments were less effective than Temik for nematode and spider mite suppression
- First- Tracer (Spinosad)- soft on beneficials, great on Tobacco Budworm
- Later- Steward (indoxacarb), Prevathon (rynaxypyr)- long residual and rain fastness, Belt (flubendiamide)
- All much more effective on small worms and require good coverage (ground application superior to air)
- Bollgard
- Single gene
- Weak concentration of Bt in blooming zone of plant leading to mid season bollworm escapes under bloom tag
- Benefits of pyrethroids overspray in mid-late July for sub threshold level of multiple pests
- WideStrike
- Two gene
- Second gene effective on fall armywor
- Weak concentration of Bt in terminal (original work Beltwide was at Prattville
- Scouting technique must be different than Bollgar
- Under pressure, WideStrike required overspray with pyrethroid
- Bollgard II
- Two gene
- Reduced bollworm escapes by about 80-90% over Bollgar
- Broaden caterpillar spectrum over single gen
- Second gene has long term benefit in resistance managemen
- No refuge requirement
- Bayer Twin Link
- Two Bt insect genes and
- Caterpillar effectiveness between WideStrike and BGII
- Bollgard III
- Contains third insect gen
- Third gene not Bt so has different mode of actio
- Should provide long term caterpillar resistance managemen
- Lygus Genetics
- Early stages of developmen
- Evaluated 40 lines of genetically altered cotton for lygus in 2011, Prattville
- Early 1990’s documented that not all equal for fall armyworm control. Karate, bifenthrin (Capture) superior
- More recently developing data to show that bifenthrin not as effective on bollworm species
- Pyrethroids not effective on the brown stink bug; however, bifenthrin superior to other pyrethroids
- Some generic pyrethroids may not be as effective as the “brand” names
- Current low spray environment
- Development of boll feeding bugs and sucking pests (plant bug and stink bug complex, leaf footed bugs)
- Role of IGR Diamond for plant bug management
- Reemergence of spider mites as an economic pest of cotton (influenced by movement from Temik to seed treatments)
- Work to develop best scouting technique
- Now sample 10-12 day old bolls for internal injury
- Worked with other southeastern states to develop a “dynamic” threshold for stink bugs. One that considered the number of bolls at risk at a given point in the season
- Conducted research on which new insecticides provide the best caterpillar control
- How to best manage beneficials, plant bugs, and early mid-season pests
- Trials indicate that weed control costs similar in both conventional and generic systems
- Tobacco budworms are the budget buster in a conventional system
- Can make only one TBW spray per season with the savings from no insect technology fee
- Discovered role of fire ants in both conventional and generic systems
- Are the dominant beneficial in Alabama cotton today
- Not only important in conventional systems but also reduces escapes in Bollgard and WideStrike (Example: Mississippi consultants spray BGII on % egg lay)
- Some chemicals suppress fire ants more than others (Centric, Steward, pyrethroids, imidacloprid)
- Dr. Tim Reed and I conducted a project at Prattville last season (Poster Presentation)
- Results show less boll damage on both conventional and genetic cotton with fire ants in system as opposed to no fire ants
 |
| Impact of Fire Ants On Bollworm Damage in Alabama Cotton |
- Grasshoppers have increased in importance in reduced tillage environment
- Pose risk to stands
- $$$ greater investment in front end of season production cost now compared to old days
- Immature G.H. easy to control, adults difficult
- Ideal timing is when “burning down” in early spring
- Most all labeled chemicals, including the IGR (Dimlin), work on immature at low labeled rates
- Lab studies conducted by Dr. Bill Moar, who has since moved onto the Monsanto resistance management team
- His findings indicate that bollworms have the ability to develop resistance to Bt in the lab– but they usually are unfit for survival when they do so.
The ACC did not fund all of every project completed over the past 20-30 years. However, your support often made it possible to be in a learning situation on insect outbreaks; new emerging pests/problems and on projects/trials that were not directly funded. Some of you may remember that my grants in earlier years were entitled “To look at New Chemistry and Technology and Determine Where They Best Fit in Alabama Cotton Production”. This allowed us to know more about the strengths and weaknesses of new chemistry/technology than even the companies bringing them to the market. Cotton insect research is unlike most of the other disciplines in that it requires much more hands on involvement. Often times, support from multiple sources had to be pooled to provide the labor and travel to conduct cotton insect trials. Fifteen to 20 trips to a research site are often required between planting and harvest. This is especially true with the genetic technology under development.
A final point I would like to make is that we in Extension have conducted basically all the cotton insect research since the early 1990’s without an Ag Research station counterpart. We feel that we have kept Alabama growers up-to-date and often ahead of the curve in cotton insect management, when compared to other states. Much of the credit goes to the support we have received from the Alabama Cotton Commission.
Wednesday, July 27, 2011
Aphid numbers continue to build, while most insects numbers remain at moderate levels
Insect conditions have not changed greatly in the past week or so. Aphids have continued to build in more fields. All other insects are low to moderate levels (mostly sub-threshold). These include plant bugs (including a few clouded plant bugs coming into the mix), bollworms, tobacco budworms and stink bugs. Most growers do not have enough of a single species to apply controls for. The two biggest surprises at this point in the season are the low number of bollworms and the low number of stink bugs in most fields. Numerous fields of conventional cotton still have less than 2 bollworms per 100 plants. Boll damage to stink bugs is less than 10% in most fields.
Most of the state has had abundant thunderstorms for several consecutive weeks. Cotton yield prospects have improved greatly and, if conditions continue, numerous fields have two bale plus potential. The two biggest limitations we now have are fields with “skippy” stands and too much late maturing cotton.
Most of the state has had abundant thunderstorms for several consecutive weeks. Cotton yield prospects have improved greatly and, if conditions continue, numerous fields have two bale plus potential. The two biggest limitations we now have are fields with “skippy” stands and too much late maturing cotton.
Monday, July 11, 2011
Tarnished plant bug, aphid, tobacco budworm and fall armyworm numbers on the increase
Tarnished plant bug adults were found in numerous fields in western Alabama (Lamar County) on Friday (July 8). Pin head square loss was minimal (less than 5%) and very few immature plant bugs were found. This would indicate that adults had moved into cotton fairly recently. However, this is a situation where damage could increase rapidly if controls are not applied.
Several calls were received late last week about increasing aphid populations in some fields. Aphids are late developing this season, which means they also could be late crashing from the fungal disease. This being the case, the peak aphid stress will come during the early boll set window. Growers may find it best to apply aphid controls and prevent plant stress at this stage of maturity.
Heavy tobacco budworm damage has been occurring on sentinel plots of conventional cotton in SW Georgia for the past week. Growers with Bollgard II and Widestrike can sleep well at night knowing that their investment in technology is working to near perfection.
The “grass” strain of the fall armyworm is now damaging pastures and hay crops in several south Alabama counties. This strain will also feed on peanut foliage but will not feed on cotton.
Several calls were received late last week about increasing aphid populations in some fields. Aphids are late developing this season, which means they also could be late crashing from the fungal disease. This being the case, the peak aphid stress will come during the early boll set window. Growers may find it best to apply aphid controls and prevent plant stress at this stage of maturity.
Heavy tobacco budworm damage has been occurring on sentinel plots of conventional cotton in SW Georgia for the past week. Growers with Bollgard II and Widestrike can sleep well at night knowing that their investment in technology is working to near perfection.
The “grass” strain of the fall armyworm is now damaging pastures and hay crops in several south Alabama counties. This strain will also feed on peanut foliage but will not feed on cotton.
Monday, June 27, 2011
Tarnished Plant Bugs Threatening Cotton Yields
Tim Reed, Extension Entomologist
June 21, 2011
Control measures for tarnished plant bugs (TPB’s) in the oldest cotton fields in north Alabama began two weeks ago and initial applications continue to be applied to later planted fields. Consultants report TPB pressure to be higher than normal than at this time last year and there is concern that some fields, especially older fields may require two TPB treatments. The cooler, wetter weather we are having this week in parts of Alabama will be favorable to TPB’s. The longer TPB treatments are postponed the more eggs are deposited by adult TPB’s which result in higher numbers of immature TPB’s present in late June and July. One consultant reports that TPB’s can presently be collected in a sweep net at any time of the day in north Alabama cotton fields but they tend to be more abundant on field edges. Some cotton fields in Montgomery county this week are also suffering 20% (Bt cotton threshold) or better pin head square loss due primarily to TPB damage and there could be control measures initiated in this central Alabama county this week. TPB’s are a much more serious pest for conventional cotton producers than for Bt cotton growers since all available chemicals that control adult plant bugs also significantly reduce beneficial insects/spiders. This increases the chances of a severe tobacco budworm infestation in the last half of June. Conventional cotton growers have a difficult time deciding on whether or not to spray for adult plant bugs in mid-June when they know it will be expensive to “fight” worms. Dry weather makes the decision even more difficult. Mississippi entomologists are reporting higher than normal numbers of tobacco budworm moths being collected in pheromone traps and budworm moths are now depositing low numbers of eggs on cotton in Montgomery county. Another concern for all cotton producers is the fear of spider mite populations increasing after TPB applications. Spider mites tend to appear in the same areas each year. Thus far a few north Alabama cotton fields have been treated with bifenthrin to help slow spider mites. Serious spider mite problems will require more expensive chemistry and consultants hope disease will take out the spider mites before more costly chemicals are required.
Monday, August 16, 2010
Insect Blog 8-16-10
Weather- Temperatures remain high 90-95 degrees Fahrenheit and rainfall extremely scattered statewide, as of today (8/16). Hay, pastures, peanuts and soybeans in many areas would profit greatly from rainfall. Most cotton fields are beyond benefit from water.
Fall Armyworms- Populations continue in hay, pastures and peanuts. However, in many south Alabama locations the previous generation has cycled out. Another generation may be possible 2-3 weeks ahead.
Tobacco Budworms- An extremely heavy moth flight and egg lay was observed on cotton in Seminole County, GA on 8/11. Only late planted conventional cotton will be at risk from this pest. However, it might be noted that budworms are now infesting soybeans in sizable numbers in some southern locations.
Podworms/Soybeans- Soybean growers should be very alert for corn earworm infestations on beans that are anywhere from R1-R7 (blooming to filled pods that are still green).
Bean Leaf Beetles/Soybeans- Several Tennessee Valley fields have subeconomic levels of bean leaf beetles in soybeans.
Lesser Corn Stalk Borer/Peanuts- Dr. Ayanava Majumdar, Extension peanut entomologist, has issued a high alert for LCSB in peanuts based on a sharp increase in moth numbers captured in traps. Counties in extreme southeastern Alabama are also very hot and dry, which is ideal weather for LCSB outbreaks.
New Registration (Belt)- Belt insecticide, marketed by Bayer, received registration on soybeans on 8/12. The label rate is 2-3 oz per acre. Belt has activity on most all caterpillar pests and is at its best on foliage feeders.
Fall Armyworms- Populations continue in hay, pastures and peanuts. However, in many south Alabama locations the previous generation has cycled out. Another generation may be possible 2-3 weeks ahead.
Tobacco Budworms- An extremely heavy moth flight and egg lay was observed on cotton in Seminole County, GA on 8/11. Only late planted conventional cotton will be at risk from this pest. However, it might be noted that budworms are now infesting soybeans in sizable numbers in some southern locations.
Podworms/Soybeans- Soybean growers should be very alert for corn earworm infestations on beans that are anywhere from R1-R7 (blooming to filled pods that are still green).
Bean Leaf Beetles/Soybeans- Several Tennessee Valley fields have subeconomic levels of bean leaf beetles in soybeans.
Lesser Corn Stalk Borer/Peanuts- Dr. Ayanava Majumdar, Extension peanut entomologist, has issued a high alert for LCSB in peanuts based on a sharp increase in moth numbers captured in traps. Counties in extreme southeastern Alabama are also very hot and dry, which is ideal weather for LCSB outbreaks.
New Registration (Belt)- Belt insecticide, marketed by Bayer, received registration on soybeans on 8/12. The label rate is 2-3 oz per acre. Belt has activity on most all caterpillar pests and is at its best on foliage feeders.
Friday, July 16, 2010
Stink bugs, tarnished plant bugs and "worms" in cotton
My cotton insect observations this week were as follows: many fields have a number of immature (late instar, soon to be adult) tarnished plant bugs. This stage of immature, along with the adult stage, is what will be giving us our “dirty” blooms in the days ahead. Mixed in with these immature TPBs are a few fleahoppers (both immature and adults) and a few immature clouded plant bugs. Many fields would profit from a plant bug complex “clean-up” spray if it has not already been done during the past two weeks.
Aphids have built rapidly during the past week in a number of fields. Where cotton is currently under drought stress, the presence of aphids and honeydew on all plants might influence the choice of chemistry for this bug clean-up spray.
Several fields of April planted cotton in southeast Alabama had treatable levels of “worms” this week. These worms were likely already about a week old on July 15, which means the eggs were deposited around July 5. This was during the period when most moths observed were tobacco budworms. Appropriate chemistry would be needed if targeting these worms. By next week (July 19-26) the eggs deposited will likely be bollworms and pyrethroids would be the most economical chemistry.
Even though the percent internal boll damage may not have increased in recent days, the brown stink bug problem has not gone away. My thought as to why the percent damage hasn’t gone up is due the fact that peak boll production is close in cotton planted in late April. Let me explain. A week or two ago we had about one boll per row foot about 10-12 days old (the size stink bugs prefer). Some of our stink bug damage levels at that time were running 20% or more. At one per foot this would be about 14000 bolls per acre x 20% or 2800 per acre with internal damage. At present these same fields have up to 3 or more 10-12 day old bolls per row foot. This would mean that 42000 bolls per acre are at risk, but the stink bug population hasn’t increased greatly at this point. The percent internal stink bug damaged bolls has gone down in many fields but that doesn’t mean we are not taking economic damage. Ten percent damage to 42000 bolls per acre is 4200 bolls. Percentages can be misleading. The damage we are incurring is a function of two things – the number of bugs present and the number of bolls at risk. In the old days this situation existed with the number of squares and the number of boll weevils. The damage percent would go down prior to increasing rapidly.
Not only will we wake up one day a couple of weeks down the road with more internal stink bug damage than we thought, but also with a sharp increase in the percent damage. This will be a function of more stink bugs present by then, but also a reduction in the number of bolls per acre that are in the desired feeding size. Borrowing a line from one of our recent politicians “this makes sense to me – does it to you”?
Aphids have built rapidly during the past week in a number of fields. Where cotton is currently under drought stress, the presence of aphids and honeydew on all plants might influence the choice of chemistry for this bug clean-up spray.
Several fields of April planted cotton in southeast Alabama had treatable levels of “worms” this week. These worms were likely already about a week old on July 15, which means the eggs were deposited around July 5. This was during the period when most moths observed were tobacco budworms. Appropriate chemistry would be needed if targeting these worms. By next week (July 19-26) the eggs deposited will likely be bollworms and pyrethroids would be the most economical chemistry.
Even though the percent internal boll damage may not have increased in recent days, the brown stink bug problem has not gone away. My thought as to why the percent damage hasn’t gone up is due the fact that peak boll production is close in cotton planted in late April. Let me explain. A week or two ago we had about one boll per row foot about 10-12 days old (the size stink bugs prefer). Some of our stink bug damage levels at that time were running 20% or more. At one per foot this would be about 14000 bolls per acre x 20% or 2800 per acre with internal damage. At present these same fields have up to 3 or more 10-12 day old bolls per row foot. This would mean that 42000 bolls per acre are at risk, but the stink bug population hasn’t increased greatly at this point. The percent internal stink bug damaged bolls has gone down in many fields but that doesn’t mean we are not taking economic damage. Ten percent damage to 42000 bolls per acre is 4200 bolls. Percentages can be misleading. The damage we are incurring is a function of two things – the number of bugs present and the number of bolls at risk. In the old days this situation existed with the number of squares and the number of boll weevils. The damage percent would go down prior to increasing rapidly.
Not only will we wake up one day a couple of weeks down the road with more internal stink bug damage than we thought, but also with a sharp increase in the percent damage. This will be a function of more stink bugs present by then, but also a reduction in the number of bolls per acre that are in the desired feeding size. Borrowing a line from one of our recent politicians “this makes sense to me – does it to you”?
Tuesday, July 13, 2010
Aphids and bug complex building, fall armyworms in second generation in pastures, fleahoppers appear
We’re getting more reports of aphids building in cotton. They’ve been slow to increase but still have reached treatable levels in some fields. While we were doing our beat sheets last week, I noticed in some of the older cotton that immature brown stink bugs were turning up where we had adult brown stink bugs earlier. So, they’ve been in there long enough now to turn over a generation. Most of the plant bug population right now are in immature forms coming off of the June adults. Fields that were sprayed for bugs appear to be pretty clean, but others have populations now that are at or will shortly be at damaging levels, so we’re really close to making applications to clean up the bug complex on everything.
We’re still not seeing signs of the huge tobacco budworm flight that was underway in southwest Georgia 2 weeks ago. It’s amazing how fast budworm activity drops off as you travel 2 counties west into Alabama. We have a long history of similar patterns – heavy pressure in south Georgia but hardly anything in southeast Alabama. We’re into the second generation of fall armyworms, the grass strain, in coastal Bermuda and other hay fields in southeast Alabama.
The garden fleahopper has been causing damage in a 25-acre cotton field in Mobile County. This is the first time I’ve seen the pest in cotton in the 39 years I’ve been working the crop and didn’t know for sure what the insect was when a consultant emailed me samples of the pest and damage. But Mississippi State University recently released an excellent color insect guide for cotton, and the garden fleahopper was included in it, which allowed me to ID the insect. Evidently, it’s been enough of a pest at some point in Mississippi cotton that it made the book.
I have a feeling we’ll see a lot of brown stink bugs in soybeans when they start setting pods. They’re certainly nearby, although probably not in soybeans to any degree yet. Stink bugs are smart enough that they won’t hang around too long in a crop that doesn’t provide a food source. Typically, they’ll leave corn within a week of when it starts drying down and, as if on cue, they’ll shift into soybeans when they start setting pods. We’re following a population of them right now at our Gulf Coast research station.
We’re still not seeing signs of the huge tobacco budworm flight that was underway in southwest Georgia 2 weeks ago. It’s amazing how fast budworm activity drops off as you travel 2 counties west into Alabama. We have a long history of similar patterns – heavy pressure in south Georgia but hardly anything in southeast Alabama. We’re into the second generation of fall armyworms, the grass strain, in coastal Bermuda and other hay fields in southeast Alabama.
The garden fleahopper has been causing damage in a 25-acre cotton field in Mobile County. This is the first time I’ve seen the pest in cotton in the 39 years I’ve been working the crop and didn’t know for sure what the insect was when a consultant emailed me samples of the pest and damage. But Mississippi State University recently released an excellent color insect guide for cotton, and the garden fleahopper was included in it, which allowed me to ID the insect. Evidently, it’s been enough of a pest at some point in Mississippi cotton that it made the book.
I have a feeling we’ll see a lot of brown stink bugs in soybeans when they start setting pods. They’re certainly nearby, although probably not in soybeans to any degree yet. Stink bugs are smart enough that they won’t hang around too long in a crop that doesn’t provide a food source. Typically, they’ll leave corn within a week of when it starts drying down and, as if on cue, they’ll shift into soybeans when they start setting pods. We’re following a population of them right now at our Gulf Coast research station.
Thursday, July 1, 2010
Tobacco Budworm Moth Flight
Another significant insect event is now occurring in extreme southwestern Georgia. Consultants yesterday were reporting a very heavy tobacco budworm moth flight with eggs on most every plant. This event means nothing to growers who have planted Bollgard or WideStrike varieties. However, to those with fields planted to conventional varieties, it is a different predicament. On the one hand they have adult stink bugs and hatching immature plant bugs, while on the other they need beneficials to be present during this upcoming budworm flight. This budworm moth activity will likely extend across southern counties of Alabama during the next 10 days, and may even reach the central Alabama area. Tobacco plants, grown as a sentinel crop in Prattville, AL had budworms from the previous generation of budworms. The budworm egg lay on tobacco at Headland, (southeast Alabama) continued from Memorial Day in May until about June 20. It will be difficult to advise growers with conventional cotton during the first weeks of July. They just need to realize that most worms will be budworm species and pyrethroids will not give worm control during this window of the season.
Wednesday, June 16, 2010
Tobacco Budworms on peanut foliage and Fall Armyworms in pastures
On 6/15/2010 tobacco budworms were reported to be feeding on foliage of peanuts in several locations across southern Alabama. A similar situation occurred in 2008 which required controls to prevent complete defoliation. Also on 6/15 Fall Armyworms (likely the grass strain) were reported in high numbers on hay fields in south Alabama. Controls were being applied.
High numbers of adult tarnished plant bugs continue to occur in many, but not all, cotton fields in central and southern Alabama. Controls may be warranted if pinhead square retention drops below 80% in Bollgard and WideStrike varieties. It would not be wise to treat conventional cotton for plant bugs during this tobacco budworm flight.
High numbers of adult tarnished plant bugs continue to occur in many, but not all, cotton fields in central and southern Alabama. Controls may be warranted if pinhead square retention drops below 80% in Bollgard and WideStrike varieties. It would not be wise to treat conventional cotton for plant bugs during this tobacco budworm flight.
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