Bugs and Bollworms

Howdy,

  I am still seeing a few different plant bug species around, in cotton as well as other crops, but we should be able to stop worrying about damage from these plant bugs in cotton soon. Once bolls get larger and we reach 350 degree days (DD60) past 5 Nodes Above White Flower (NAWF), we can stop scouting for plant bugs. Most of the cotton in my scouting program is between 6 and 3 NAWF.

  The threshold for verde plant bugs is 20-25 insects per 100 plants with using a beat bucket. Verdes can feed on fruit up to bolls about an inch in diameter.

Nymph (A) and adult (B) of Verde plant bug, Creontiades signatus Distant (Hemiptera: Miridae), which causes lint and seed staining and deterioration, seen in green (C) and open (D) cotton bolls. https://ccag.tamu.edu/entomology/

  I have seen stink bugs in cotton this year, damage thus far has been low, but some locations have needed treatment. To scout for stink bugs pull 10 to 20 bolls about an inch in diameter from four places in the field. Check the inside of the bolls for warts, lesions, and stained lint. The economic threshold for stink bugs is 20% or more of the bolls with internal damage and stink bugs present. Some of the brown stink bug populations in our area have also been shown to have some resistance to pyrethroids. 

Green Stink Bug adult
Photo: Kate Crumley

Carpal Wall Warts from Stink Bug feeding damage
Photo: Kate Crumley

  This week our scouting was limited with the rainfall, but we still picked up worm pressure, and several places we did not get to check were treated before the rain.

Jackson County

Bollguard 3 near Vanderbilt

12% bollworm eggs
4% small bollworm larvae
6% bollworm damage

Bollguard 2 field near El Toro
12% bollworm eggs
2% small bollworm larvae

5% bollworm damage
2% stink bug damage bolls

Matagorda County

Widestrike near Tin Top

8% bollworm eggs

8% bollworm larvae- 6% large, 2% small
8% bollworm damage squares
4% bollworm damaged bolls

Bollguard 3 near Jackson Matagorda county line on 35

8% bollworm eggs
6% small bollworm larvae
7% bollworm damage
1% stink bug damaged small boll


Widestrike 3 Near Jackson Matagorda county line on 35

8% bollworm eggs
4% small bollworm larvae

8% bollworm damage

Field with a combination of Bollguard 2 and 3 near Palacios

5% bollworm eggs
0% bollworm larvae
8% bollworm damage
4% stink bug damaged small bolls

  These are caterpillars that feed on multiple crops and vegetables. In cotton they feed on squares and bolls, causing fruit loss. The last few years we had high numbers of this insect in our Bt cotton as well. The eggs of this insect are small and white, turning brown as they get closer to hatching. The caterpillars are also highly cannibalistic, the eggs are normally laid singly, but if you find a couple or more on the same leaf, count it as one.

H. zea eggs
Photo: Kate Crumley

H. zea caterpillar in cotton square
Photo: Kate Crumley

H. zea moth
Photo: Kate Crumley

  To scout for cotton bollworms I use the terminal and square inspection method. I make about four stops in a field, more if the field is larger than 100 acres. At each stop, I look at 25 plant terminals, checking at least the upper third of the plant for caterpillars and eggs. I also pull 25 half grown or larger green squares to bolls and look for bollworm damage. Recently the egg lay has been in oddball places. We have been finding eggs in the lower 1/3 of the plant, as well as in bloom tags and bracts on fruit. When documenting egg lay, if I find more than one on a leaf, I only count it as one. This caterpillar is highly cannibalistic, and generally only one caterpillar will result from eggs too near each other. The economic threshold for bollworms is 6% damaged bolls with live caterpillars present. In areas like ours on the upper gulf coast with documented Bt failures, the threshold for eggs on single and dual gene cotton is 20% (20 plants out of 100 with at least one egg). If you're finding bollworms in cotton or in corn, especially in viptera fields, please give me a call.

H. zea eggs on cotton bloom tag
Photo: Ben Crumley

Cotton Insect Guide

 The current A&M recommendation is to use pyrethroids with caution. In areas needing residual control Prevathon at 18-20 fl oz or Besiege at 9-10 fl oz works well. If you don't need residual control you can get by with Prevathon at 14 fl oz or Besiege at 7-8 fl oz. I've seen a few places where folks have gone out with imidacloprid and bifenthrin, but this combination does not work well to kill bollworm eggs in the field or moths.

Cotton Insect Guide

  

  Stephen Biles and I recorded our fourth audio update this week. These updates will be going out once a week on what we are seeing going on in our areas. If you are interested in checking that out, you can sign up to receive text updates when we post them on Thursday afternoons at this website https://www.texasinsects.org/signup-coast.html.

DD60 this season:

If you're looking for information on dicamba check out:

Texas Agriculture Law Update

Texas Department of Agriculture Statement

Court Decision Document

  Stay dry and have a good weekend everyone!

Sincerely,

Kate Crumley

For More Information:

Cotton Insect Guide

Aphids in Cotton

Cotton Growth and Development overview

Cotton Growth and Development

Prevention of Plastic Contamination

Kudzu Bugs

Murder Hornets

Murder Hornet Lookalikes in Texas

Managing Insect and Mite Pests of Texas Sorghum

Managing Soybean Insects in Texas

For More Information on COVID-19:

Texas Department of State Health Case Counts

TAMU Guides

How to Make Cloth Face Masks

Bollworms and Stink Bugs

Howdy,

  I am still seeing a few different plant bug species around, in cotton as well as other crops, but we should be able to stop worrying about damage from these plant bugs in cotton soon. Once bolls get larger and we reach 350 degree days (DD60) past 5 Nodes Above White Flower (NAWF), we can stop scouting for plant bugs. Most of the cotton in my scouting program is between 9 and 5 NAWF.

  The threshold for verde plant bugs is 20-25 insects per 100 plants with using a beat bucket. Verdes can feed on fruit up to bolls about an inch in diameter.

Nymph (A) and adult (B) of Verde plant bug, Creontiades signatus Distant (Hemiptera: Miridae), which causes lint and seed staining and deterioration, seen in green (C) and open (D) cotton bolls. https://ccag.tamu.edu/entomology/

  Lygus bugs will also feed on cotton squares, flowers, and small bolls. Feeding can cause damage to blooms (dirty blooms and damaged anthers, or puckered petals), deformed bolls, stunted growth, fruit shed, and small lesions on bolls.

Lygus Bug nymph
Photo: Kate Crumley

Lygus Bug adult
Photo: Kate Crumley

Chart from Cotton Insect Guide

  I have seen few stink bugs in cotton this year, but damage is picking up. To scout for stink bugs pull 10 to 20 bolls about an inch in diameter from four places in the field. Check the inside of the bolls for warts, lesions, and stained lint. The economic threshold for stink bugs is 20% or more of the bolls with internal damage and stink bugs present. Some of the brown stink bug populations in our area have also been shown to have some resistance to pyrethroids. 

Green Stink Bug adult
Photo: Kate Crumley

Carpal Wall Warts from Stink Bug feeding damage
Photo: Kate Crumley

  We've picked up a few eggs and bollworms in fields this week. In Wharton county we picked up 0% eggs and 8% damaged squares in a field near the fairgrounds, 8% eggs with 6% small worms and 10% damaged squares, 6% eggs and 8% damaged squares, and 21% eggs and 4% damaged squares in another. In the blue creek area we found 15% eggs with 3% damaged squares, 9% eggs with 1% small worms and 4% damaged squares, and 0% eggs with 4% damaged squares in another. Near Danavang we found 4% eggs and 3% small worms with 8% damage. Near Elm Grove we picked up 11% eggs with 3% small worms and 7% damage, near Egypt we found 6% eggs with 2% small worms and 4% damaged squares. There were 20% eggs, 4% small worms, and 8% damaged squares in a field near the airport.

  In Jackson county we found 2% eggs in a field near El Toro with 2% damaged squares, 6% eggs with 2% small worms and 6% damaged squares near Vanderbilt, and 22% eggs with 6% damaged squares near La Salle. In one field near the county line off 35 we picked up 3% eggs with 1% fruit damage, and 3% stink bug damage. In the other field near there we found 5% eggs and 4% damaged squares and 3% stink bug damage.

  In Matagorda county we found 3% eggs with 4% small worms and 13% damaged fruit at Tin Top, 7% eggs with 4% small worms and 7% damaged squares near Tidehaven, and 4% eggs with 1% small worms and 3% damaged fruit near Palacios.

  These are caterpillars that feed on multiple crops and vegetables. In cotton they feed on squares and bolls, causing fruit loss. The last few years we had high numbers of this insect in our Bt cotton as well. The eggs of this insect are small and white, turning brown as they get closer to hatching. The caterpillars are also highly cannibalistic, the eggs are normally laid singly, but if you find a couple or more on the same leaf, count it as one.

H. zea eggs
Photo: Kate Crumley

H. zea caterpillar in cotton square
Photo: Kate Crumley

H. zea moth
Photo: Kate Crumley

  To scout for cotton bollworms I use the terminal and square inspection method. I make about four stops in a field, more if the field is larger than 100 acres. At each stop, I look at 25 plant terminals, checking the upper third of the plant for caterpillars and eggs. I also pull 25 half grown or larger green squares to bolls and look for bollworm damage. This week there were a few moths flying around in a couple of the fields in Matagorda county, and in one near Palacios we found two eggs laid. When documenting egg lay, if I find more than one on a leaf, I only count it as one. This caterpillar is highly cannibalistic, and generally only one caterpillar will result from eggs too near each other. The economic threshold for bollworms is 6% damaged bolls with live caterpillars present. In areas like ours on the upper gulf coast with documented Bt failures, the threshold for eggs on single and dual gene cotton is 20% (20 plants out of 100 with at least one egg). If you're finding bollworms in cotton or in corn, especially in viptera fields, please give me a call.

Cotton Insect Guide

 The current A&M recommendation is to use pyrethroids with caution. In areas needing residual control Prevathon at 18-20 fl oz or Besiege at 9-10 fl oz works well. If you don't need residual control you can get by with Prevathon at 14 fl oz or Besiege at 7-8 fl oz. I've seen a few places where folks have gone out with imidacloprid and bifenthrin, but this combination does not work well to kill bollworm eggs in the field.

Cotton Insect Guide

  

  This week I was able to make a few checks in sorghum. We found moderate numbers of rice stink bugs and a few headworms in the field, as well as a slight increase in sugarcane aphid numbers from last week. None of the insects were over threshold in the fields I looked at, but in places headworm and stink bug numbers have been high. If you've got high numbers of sugarcane aphids, give me a call.

Managing Insect and Mite Pests of Texas Sorghum

Managing Soybean Insects in Texas

  Stephen Biles and I recorded our third audio update this week. These updates will be going out once a week on what we are seeing going on in our areas. If you are interested in checking that out, you can sign up to receive text updates when we post them on Thursday afternoons at this website https://www.texasinsects.org/signup-coast.html.

DD60 this season:

If you're looking for information on dicamba check out:

Texas Agriculture Law Update

Texas Department of Agriculture Statement

Court Decision Document

  Stay safe and have a good weekend everyone!

Sincerely,

Kate Crumley

For More Information:

Cotton Insect Guide

Aphids in Cotton

Cotton Growth and Development overview

Cotton Growth and Development

Prevention of Plastic Contamination

Kudzu Bugs

Murder Hornets

Murder Hornet Lookalikes in Texas

For More Information on COVID-19:

Texas Department of State Health Case Counts

TAMU Guides

How to Make Cloth Face Masks

Bollworm Eggs and Stink Bugs

Howdy,

  The Jackson county Ag Tour will be taking place on Monday, June 15 at 4:00 pm. The tour starts at the sorghum demonstration on the Kulak Farm on CR 325 north of La Salle. There will be 2 CEU credits available for $10. More information on the crop tour can be found at: https://jackson.agrilife.org/files/2020/05/2020-Jackson-County-Ag-Tour.pdf

  I am still seeing a few different plant bug species around, in cotton as well as other crops. The threshold for verde plant bugs is 20-25 insects per 100 plants with using a beat bucket. Verdes can feed on fruit up to bolls about an inch in diameter.

Nymph (A) and adult (B) of Verde plant bug, Creontiades signatus Distant (Hemiptera: Miridae), which causes lint and seed staining and deterioration, seen in green (C) and open (D) cotton bolls. https://ccag.tamu.edu/entomology/

  Lygus bugs will also feed on cotton squares, flowers, and small bolls. Feeding can cause damage to blooms (dirty blooms and damaged anthers, or puckered petals), deformed bolls, stunted growth, fruit shed, and small lesions on bolls.

Lygus Bug nymph
Photo: Kate Crumley

Lygus Bug adult
Photo: Kate Crumley

Chart from Cotton Insect Guide

  I have seen few stink bugs in cotton this year, but damage is starting to pick up a bit. To scout for stink bugs pull 10 to 20 bolls about an inch in diameter from four places in the field. Check the inside of the bolls for warts, lesions, and stained lint. The economic threshold for stink bugs is 20% or more of the bolls with internal damage and stink bugs present. Some of the brown stink bug populations in our area have also been shown to have some resistance to pyrethroids. 

Green Stink Bug adult
Photo: Kate Crumley

Carpal Wall Warts from Stink Bug feeding damage
Photo: Kate Crumley

  I have not seen any bollworms, Helicoverpa zea, in fields yet this year, but I have started picking up low numbers of eggs. In Wharton county we picked up 9% eggs and 3% damaged squares in a field near the fairgrounds, 0% eggs with 4% damaged squares, 8% eggs and 6% damaged squares, and 2% eggs and 4% damaged squares, and 0% in another near the fairgrounds. In the blue creek area we found 7% eggs with 3% damaged squares, 21% eggs with 3% damaged squares, and 9% eggs with 3% damaged squares in another. Near Danavang we found 1% eggs. Near Elm Grove we picked up 2% eggs, near Egypt we found 6% eggs and 6% damaged squares. There were 4% eggs, 2% small worms, and 8% damaged squares in a field near the airport.
In Jackson county we found no eggs in a field near El Toro with no damaged squares, 12% eggs with 2% small worms and 10% damaged squares near Vanderbilt, and no eggs with no damaged squares near La Salle. In one field near the county line off 35 we picked up 3% eggs with 9% fruit damage, and 1% stink bug damage. In the other field near there we found 1% eggs and 6% damaged squares.

  In Matagorda county we found 4% eggs with 1% small worms and 6% damaged fruit at Tin Top, and 7% eggs with 5% damaged fruit near Palacios.

  These are caterpillars that feed on multiple crops and vegetables. In cotton they feed on squares and bolls, causing fruit loss. The last few years we had high numbers of this insect in our Bt cotton as well. The eggs of this insect are small and white, turning brown as they get closer to hatching. The caterpillars are also highly cannibalistic, the eggs are normally laid singly, but if you find a couple or more on the same leaf, count it as one.

H. zea eggs
Photo: Kate Crumley

H. zea caterpillar in cotton square
Photo: Kate Crumley

H. zea moth
Photo: Kate Crumley

  To scout for cotton bollworms I use the terminal and square inspection method. I make about four stops in a field, more if the field is larger than 100 acres. At each stop, I look at 25 plant terminals, checking the upper third of the plant for caterpillars and eggs. I also pull 25 half grown or larger green squares to bolls and look for bollworm damage. This week there were a few moths flying around in a couple of the fields in Matagorda county, and in one near Palacios we found two eggs laid. When documenting egg lay, if I find more than one on a leaf, I only count it as one. This caterpillar is highly cannibalistic, and generally only one caterpillar will result from eggs too near each other. The economic threshold for bollworms is 6% damaged bolls with live caterpillars present. In areas like ours on the upper gulf coast with documented Bt failures, the threshold for eggs on single and dual gene cotton is 20% (20 plants out of 100 with at least one egg). If you're finding bollworms in cotton or in corn, especially in viptera fields, please give me a call.

Cotton Insect Guide

 The current A&M recommendation is to use pyrethroids with caution. In areas needing residual control Prevathon at 18-20 fl oz or Besiege at 9-10 fl oz works well. If you don't need residual control you can get by with Prevathon at 14 fl oz or Besiege at 7-8 fl oz.

Cotton Insect Guide

  

  This week I was able to make a few checks in sorghum and soybeans. We did pick up rice, green, and brown stink bugs in sorghum, in addition to a few species of headworms and low numbers of sugarcane aphids. If the weather stays dry I would not be surprised to see an increase in aphid populations. If you've got high numbers of sugarcane aphids, give me a call. In the soybeans we found low numbers of red banded, green, brown, rice, and a few predatory species of stink bugs.

Managing Insect and Mite Pests of Texas Sorghum

Managing Soybean Insects in Texas

  Stephen Biles and I recorded our third audio update this week. These updates will be going out once a week on what we are seeing going on in our areas. If you are interested in checking that out, you can sign up to receive text updates when we post them on Thursday afternoons at this website https://www.texasinsects.org/signup-coast.html.

  Last week the United States Court of Appeals for the Ninth Circuit issued a ruling vacating the federal registration for three dicamba herbicide products, Xtendimax, FeXapan, and Engenia. I know several of you have questions on this, and the links below are the most up to date info I've seen on this:

Texas Agriculture Law Update

Texas Department of Agriculture Statement

Court Decision Document

  Stay safe and have a good weekend everyone!

Sincerely,

Kate Crumley

For More Information:

Cotton Insect Guide

Aphids in Cotton

Cotton Growth and Development overview

Cotton Growth and Development

Prevention of Plastic Contamination

Kudzu Bugs

Murder Hornets

Murder Hornet Lookalikes in Texas

For More Information on COVID-19:

Texas Department of State Health Case Counts

TAMU Guides

How to Make Cloth Face Masks