Update for the Week of August 19

Our April-planted cotton is beginning to open, and has varying levels of boll rot due to the weather the past 7-14 days. This same weather pattern of frequent thunderstorms and overcast conditions has been ideal for the spread of leaf spot diseases in out late planted cotton.

Insects have been light-to-nonexistent in recent days. There are a few plant bugs present and stink bug numbers have increased in some fields. I am not sure if either are at damaging levels, especially the plant bugs.

I believe we could safely say that leaf spot diseases are potentially more important than insects for the remainder of the season.

Growers who have peanuts or soybeans should monitor these crops carefully for the remainder of the season. Peanuts are attractive to a number of foliage feeding insects – including loopers, fall armyworms, bollworms, budworms, green cloverworms, velvet bean caterpillars and cutworms. Two peanut fields in Monroe County were identified last week with a high infestation of the garden fleahopper. To my knowledge this is the first time for this insect on peanuts. I am not sure what kind of damage potential they present. However, in cotton this pest can cause extensive foliage damage by leaving all leaves with stippling type feeling.

This same type of damage in peanuts would seem to be just as economic as a foliar disease.

Soybeans would be susceptible to damage from all the leps mentioned under peanuts plus the pod feeders – podworms and stink bugs. Many of our beans are late, planted behind wheat, and were just in full bloom the past 10 days. These beans will be susceptible to insect injury for weeks ahead. Only by scouting will growers know when economic insect losses are occurring and when controls are needed. We already have some fields in Baldwin County with damaging levels of soybean loopers. Foliage loss was as high as 35% last week when I made surveys in that area. Soybeans will be the last crop that stink bugs are attracted to this season. Even though it has been a light stink bug season, if they all accumulate in soybeans late season, controls will likely be needed.

I have heard little from the Kudzu bug on soybeans after finding them in the northeast counties of Cherokee and Cleburne back in July. Follow up surveys are needed in that area whenever time permits.

As the season winds down we will get back with further updates as new information becomes available and the situation changes.

Update for the week of July 29th

The dominant question last week was concerning spider mite control. Several calls were received from consultants or agri fieldmen in the southern part of the state. Their question was not so much what to spray with (chemical choice) but instead when to spray. Most were scheduling stink bug sprays within a few days and wanted to know whether to add a miticide or not. Without seeing the fields, that is a difficult decision to make over the phone. My thoughts were that it could depend somewhat on how widespread the mites were in the field, the level of mite infestation and maybe most importantly – what is the weather outlook for the next 7-10 days.

Mite populations seem to hold steady in good rainfall patterns but explode during hot-dry weather. Even though we have had scattered thunderstorms for the past several weeks, there are many places where no rainfall has occurred. Last week was hot, mid 90’s or higher all week, so mites likely increased in number.

My suggestion would be to go ahead and treat mites if the weather outlook is for hot dry weather for the next 5-7 days. Most of our mites controls this season have been with abamectin (Agri Mek) at 8 oz/ac and results have been good.

Stink bug populations are still hanging around, in low numbers in many fields. However, from personal experience in a plant bug trial area in central Alabama that is located adjacent to corn, stink bug numbers have exploded in the past two weeks. Both brown and southern green species are well above the threshold level on the corn-cotton borders. Where cotton yields are promising and quarter diameter 10 day old bolls are still developing, stink bugs should be watched closely and controlled when above threshold. Cotton is at various stages now so our “dynamic threshold” would depend on where we are in the blooming-boll development cycle. Remember that 10% is our suggested threshold from weeks 3 through about 6 of bloom.

One other call was received last week concerning one or more fields in Baldwin County (Gulf Coast) infested with damaging levels of the garden fleahopper. We had several fields in recent seasons with this pest in the Mobile county area. The GFH seems to be primarily a foliage feeder but can damage every leaf in a field.

As of this date the bollworm/budworm complex is almost non-detectable, even in cotton with no caterpillar technology.

Weather and Insects Affect Late Season Cotton, Soybean and Peanuts

The greatest impact on cotton during the past two weeks has been the lack of rainfall. Drought and intense heat has resulted in the shed of all fruit less than 10 day old bolls from the terminals of plants. This will tend to shorten additional boll production by 2 to 3 weeks and will likely reduce the “top crop” by 200 or so pounds of lint in many fields. Rainfall in the next 7 days would still help fill top bolls that are not mature.

As the result of the above conditions, the insect control season, especially stink bugs, is about over. A few southern green stink bugs can be found in late maturing fields or “swag” areas that remain green in more mature cotton fields. Thresholds for these would be 30-50% internal boll damage on 10-12 day old bolls. A few fields would still profit from stink bug controls.

Tobacco budworms have been extremely low all season but field observations and pheromone traps indicate an increase in the past week or two. Also, bollworm moths are abundant this week in the southern counties of the state.

Soybean Insects- Soybean loopers are at economic levels of 5 or more per row foot in some Gulf Coast area soybeans. Chemical choices (in no particular order) are: Intrepid, Steward, Belt, Tracer and Besiege (Coragen and Karate). Dimilin will give good suppression and long residual. On cotton, the same can be said for Diamond.

Peanut Insects- Scouts reported a mixture of foliage feeding worms in peanuts in Monroe County (S.W. Alabama) about 10 days ago. Many of these were controlled or either they have cycled out by now. This mixture was dominated by bollworm and fall armyworm (grass strain) species. Also in the mix were a few green cloverworms, loopers, and granulate cutworms. Pyrethroids gave nice control of this mix.

Later than normal aphid buildup may require more proactive treatments

More fields were reported with aphid infestations last week. Due to this later than normal aphid buildup, growers may want to be more proactive in applying treatments. Stress from aphids, where they are occurring in 2011, is overlapping early to mid boll set. We need to set all the fruit possible in the next two weeks.


Both the brown and Southern stink green stink bug species are present at some level in many fields. Cotton planted in April and up to mid May is already into the third to sixth week of bloom. This means that we should be using a low (10%) internal damaged boll threshold for stink bugs. Growers who chose to treat for aphids should consider stink bugs when selecting their chemicals or tank mixtures.

The flight of corn earworms from corn to cotton usually occurs the week of July 20 in central Alabama. This egg lay may occur up to 7 days earlier in south Alabama and 7 days later in the northern counties. This budworm flight will only be meaningful to those who have planted conventional cotton varieties. Older larvae observed last week were likely from budworm moths that occurred 1 to 2 weeks ago.

Cotton Insect and Crop Report - Alabama 2010

Cotton was planted on 345,000 acres in 2010, an increase of about 25% over the previous year. Over 96% of the acreage contained the RoundUp gene and approximately 90% contain genes for lep control. Due to the phase out of DP555, market share was gained by Phytogen, Fibermax and Stoneville varieties.

Early season insect pressure (thrips, aphids, cutworms, grasshoppers and plant bugs) was below historical levels for the second year in a row and very limited foliar applications were necessary. More than 80% of the acres were planted with insecticide treated seed, with the remainder planted with Temik in-furrow. Midseason pests included bollworms, at below normal numbers, which dictated fewer oversprays over the varieties with stacked lep genes. Very few lep sprays were made statewide, even in fields planted to conventional varieties. 2010 was one of the lowest pressure years in history for all lep species.

Stink bugs were by far the most economic of all cotton insects. Two to four foliar sprays were needed over most of the state to hold damage below threshold level. The dominant species in 2010 was the brown stink bug, Euschistus servus. The stink bug complex remains a complex issue to many growers and fieldmen, especially as it relates to scouting techniques and thresholds.

Weather during the production season was good until about July 15-20 at which time rainfall ceased and temperatures increased to 96-102° F (days) and 78-82° F (nights) for the following two months. This combination of heat and drought took its’ toll on yields since only about 10% of the state acreage is irrigated. Therefore, an 800-1000 lb potential yield deteriorated to about 500 lbs. Certain fields in several regions of the state yielded as low as 200-250 lbs of lint/acre.

Research continued in 2010 with the newer chemistries against the bug complex, sucking pests, and leps. Also, the newer genetic technologies were also evaluated both, agronomically and entomologically, within the state.

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.

Effect of Heat and Drought on Cotton Crops

8/2/10
Last week's heat and drought was devastating to a high percent of our cotton crop in Alabama. Fields that had good moisture up until July 23 were shedding everything from stress by July 30. In my opinion this stress has cut about 4 weeks off of our cotton production season. Within a few more days the only fruit remaining on the plants will be bolls that are more than 20 days old. Plant bugs, bollworms, and budworms are likely a thing of the past for the 2010 cotton season. Even stink bugs will shortly find that the remaining fruit is too hard to penetrate internally. Growers may wish to watch the swag or greener areas of their fields. Insects may congregate in the lush areas for a while longer. We have plenty of time to recover and set more fruit but scattered thunderstorms will not provide the moisture to turn the cotton around.