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.
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.
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.
 |
| 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 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 |
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.
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:
Stay safe and have a good weekend everyone!
Sincerely,
Kate Crumley
For More Information:
No comments:
Post a Comment