Upper Coast IPM: Fleahoppers to Flowers

Howdy,

I spent the week still looking for fleahoppers and other plant bugs in cotton, but I did see my first flower this week. There's been a couple different species of plant bugs in cotton than I usually see, so feel free to contact me if you have something unusual you would like an ID on. I've heard of some verde plant bugs popping up as well. There are still aphids in some fields across all three counties.

In Jackson county I found 20% fleahoppers in my field near El Toro, 20% near Vanderbilt, 28% near La Salle, and 26% near the county line off 35. In Matagorda county I found 9% in a field near Tidehaven school, 6% near Tin Top, and 24% near Palacios. In Wharton county I found 11% near Egypt, 2% at Elm Grove, 0%, 4%, 6% at three fields and 11% in a 4th field near the fairgrounds, 0 in one field in the Blue Creek area, 15% in another near Blue Creek, 5% in Danavang, and 0% in a field close to the airport.

Aphids on CottonPhoto: Kate Crumley

Cotton Fleahopper Adult

Kate Crumley

Cotton fleahopper numbers are rising in some places this week, and with squaring under way in many fields, we'll be needing to keep a closer eye out for this pest.

Fleahopper feeding will cause squares to drop. Plants can recover for and compensate for some square loss, but the threshold for fleahoppers is 15-25 per 100 plants. I check for fleahoppers by inspecting the plant terminals once they start squaring. I look at 25 plants per stop in the field, usually checking 100 plants total in an 80-100 acre field, more if the field is larger. Fleahopper nymphs can be close to the size of aphids, but look like smaller versions of the adults without wings, and are much more mobile than aphids.

The threshold for cotton aphids is 50 aphids per leaf, and if you see the aphid mummies in the field, that's a good thing. Parasitoid wasps lay eggs in the aphids, and the aphid forms a mummy while the wasp larvae pupates inside. These wasps, lady beetles, and lacewings all can make a dent in aphid numbers. Treatment for aphids is very rarely justified since the numbers need to be so high before they can cause an economic problem. If you do decide to treat for aphids, do not use a pyrethroid. Pyrethroids are non specific, and kill predatory insects as well, but aphids will bounce back quickly due to their high reproductive rate.

The chart below contains insecticide suggestions from cottonbugs.tamu.edu (also a good resource) for reference if you have fleahoppers at the action threshold.

Next week I am going to be looking for bollworms in the cotton with flowers. To scout for cotton bollworms I use the terminal and square inspection method, as well as making some full plant checks. 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 I was finding moths flying in almost every field I was in. Egg lay has been fairly light most of this week with an increase in the last two days. I would like to note that while egg lay in the upper third of the cotton plant is typical, I have seen and have talked to consultants finding egg lay near the bottom of the plants. 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 few caterpillars I have seen were very small, likely had only molted once, and were in the crescent area of Wharton county. 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 a 7- 8 fl oz.

Cotton Insect Guide

In April there was a sighting of a kudzu bug in Cherokee county, and this was the first documented sighting of this pest in Texas. Kudzu bugs have been a problem in soybeans in Georgia, so keep an eye out for this insect in soybeans and in gardens. There is more information on this insect available at https://citybugs.tamu.edu/2020/04/20/kudzu-bug-in-texas/. Let me know if you find this insect, and I'll be looking around as well.

This week we recieved more information on our agency prociding training for the CARES Act. This includes information on programs available for ag producers. This link has the news release for that information: https://wharton.agrilife.org/2020/05/22/agrilife-provides-cares-act-training-and-outreach-for-ag-producers-affected-by-covid-19/

If you have any questions feel free to contact me. Stay safe everyone!

Sincerely,

Kate Crumley

For More Information:

Cotton Insect Guide

Aphids in Cotton