Friday, April 29, 2016

Aphids Overwintered in Hale County, Texas

Blayne Reed, Extension Agent - IPM in Hale, Swisher and Floyd counties, checked his Hale County overwintering cage today and reported successful sugarcane aphid overwintering. The study site was near Hale Center. Several Johnsongrass leaves within the cage had adults and nymphs. Aphids were not found on Johnsongrass outside the cage. Temperature recording probes were placed at the soil surface and at a two inch depth, and probe data will be added to this post next week.

Prior to today, the most northerly known overwintering was at Tommy Doederlein's study site between Lamesa and O'Donnell. The Hale County overwintering study now moves the successful overwintering line approximately 80 miles north.

Monday, April 25, 2016

Winged SCA in Hill County

Winged sugarcane aphids have been found in Hill County in the Johnsongrass where they overwintered. These aphids have the ability to move to sorghum fields, as well as other Johnsongrass patches and volunteer sorghum. It is recommended to being scouting sorghum for the aphids 3-4 weeks post-emergence. Most seed treatments should provide protection for at least 4 weeks, but varying environmental conditions (rain, soil moisture, ect) may affect their potency.

Because effective control depends on timing sprays according to population numbers, early scouting may be essential in preventing economic damage in fields.

Monday, April 18, 2016

Update for Overwintering Cages in the Texas Panhandle

Last Thursday, April 14th, I went to Dalhart, TX.  to check the sugarcane aphid overwintering cage with Mr. Mike Bragg, County Extension Agent - Dallam/Hartley county.  Mr. Bragg had set up this cage last October in the corner of a pivot field that is located about 15 miles East of Dalhart. He had placed several hundred sugarcane aphids on the johnsongrass inside and outside of the overwintering cage. When we looked inside and outside of the cage we did not find any sugarcane aphids. We only found just one or two johnsongrass sprouts emerging from the rhizomes inside or outside of the cage. We replaced the cage and we will check the cage again in May.

On my way back from Dalhart, I checked the overwintering cage at the Texas A&M AgriLife Research Station at Bushland, TX. There was more johnsongrass sprouting inside and outside of the cage. But, I was still unable to find any sugarcane aphids on the above ground leaves and stems or below ground at the base of the plant or on the rhizomes. The cage was replaced and will be checked again in May.

Monday, April 11, 2016

Texas Section 18 Transform WG Label Specifics

The Section 18 label for Transform (Sulfoxaflor) use on sorghum to control sugarcane aphid has been released, and the official version will be posted on the TDA website today or tomorrow. A COPY OF THE LABEL MUST BE IN HAND WHEN APPLICATIONS ARE MADE. The Section 18 Emergency Exemption became effective on 8 April 2016 and expires on 8 April 2017.

Here are some specifics from the Texas Section 18 Label.

  • Rate range: 0.75 to 1.5 oz. per acre.
  • Application by ground or air (no chemigation).
  • Wind speed not to exceed 10 mph.
  • Droplet Size: Use only medium to coarse spray nozzles (i.e., with median droplet size if 341 μm or greater) for ground and non-ULV aerial application according to ASABE (S 572.1) definition for standard nozzles. In conditions of low humidity and high temperatures, applicators should use a coarser droplet size except where indicated for specific crops.
  • Boom height for ground application: Not to exceed 4 feet.
  • Carrier volume for ground application: A minimum of 5 to 10 gallons per acre - to be increased with increasing crop size and/or pest density.
  • Carrier volume for aerial application: A minimum of 3 gallons per acre, but a minimum of 5 gallons per acre is recommended.
  • Preharvest Interval: Do not apply within 14 days of grain or straw harvest or within 7 days of grazing, or forage, fodder, or hay harvest.
  • A restricted entry interval (REI) of 24 hours must be observed.
  • Do not make more than two applications per acre per year.
  • Minimum Treatment Interval: Do not make applications less than 14 days apart.
  • Do not apply more than a total of 3.0 oz of Transform WG (0.09 lb ai of sulfoxaflor) per acre per year.
  • Do not apply product ≤ 3 days pre-bloom until after seed set.

Section 18 for Transform (Sulfoxaflor) Granted on Sorghum

We have just received word from Dale Scott, Texas Department of Agriculture, that EPA has granted a Section 18 request to allow the use of Transform (Sulfoxaflor) on Texas sorghum for control of sugarcane aphid in 2016. The use directions are being revised now and specific use information will be forthcoming.

This is good news in that we now have two very effective insecticides for use on sugarcane aphid (Transform and Sivanto), and both preserve beneficial insects that have a major affect on controlling aphid populations after initial insecticide application. We would like to thank Dale Scott and the Texas Department of Agriculture for a lot of hard work in getting this Section 18 request approved.

We will post more information as it becomes available.

Wednesday, April 6, 2016

Update from Hill County

SCA have been confirmed at 5 different sites around Hillsboro, TX on Johnsongrass. Sites are checked weekly and so far no winged aphids or alatoid nymphs (young aphids that will form wings) have been seen. Due to the cold weather and rain, aphids can be seen below the soil line on the stems, or even underneath the root clusters on seedling Johnsongrass.

Monday, April 4, 2016

Overwintering in Dawson County, Texas, but not Hockley County

Tommy Doederlein, Extension Agent - IPM in Dawson and Lynn counties, checked both of his sugarcane aphid overwintering cages today and found healthy aphid colonies in one of them. There were no aphids on Johnsongrass outside the cage. This cage was located between Lamesa and O'Donnell and was in a more protected location than the cage where no overwintering aphids were found. No winged aphids were found. This is the second consecutive year that Tommy has found aphids in his overwintering cages, but last year's results could not be determined to be conclusive. This year's results are conclusive, and to date Dawson county is the most northerly location in Texas where sugarcane aphid has been documented to overwinter.

Kerry Siders, Extension Agent - IPM in Hockley, Cochran and Lamb counties, examined his Hockley County overwintering cage on March 21st and did not find any sugarcane aphids, but did find yellow sugarcane aphids. He kept some unhatched spherical objects that might possibly be eggs, but nothing emerged from them. Cages to the north in Hale and Swisher counties have yet to be examined because the Johnsongrass is just emerging.

Habitat surrounding the Dawson County cage with successful overwintering.

Last fall an infested sorghum leaf was placed in the cage, and this year's aphids were on the Johnsongrass beneath and near the sorghum leaf; they had not spread to Johnsongrass on the other side of the cage. 

Aphids on Johnsongrass inside the overwintering cage.

Temperature recording probes were placed both inside and outside the cages at the ground surface and at two inches beneath the soil. 

Temperature Data Inside Cage, Top of Soil

Low temperature 20.8 degrees, Feb. 4, 2016
Hours below freezing (across all dates) = 318
Hours below 26 degrees = 46
Hours below 25 degrees = 23
Hours below 24 degrees = 15
Hours below 23 degrees = 11
Hours below 22 degrees = 2

Temperature Data Inside Cage, Buried in Soil at 2 Inches Depth

Low Temperature 36.6 degrees
Hours below freezing = 0

Friday, April 1, 2016

Sugarcane Aphid Overwintered in Roscoe, Nolan County, Texas

Sugarcane aphids successfully overwintered in Nolan County, Texas. Students at Roscoe Collegiate High School in Roscoe conducted one of the nine sugarcane aphid overwintering trials that were replicated from San Angelo to Amarillo. Yesterday they reported that sugarcane aphid successfully overwintered in their experiment. The students found sugarcane aphids inside the overwintering cage but not on the Johnsongrass outside the cage. This is the most northerly confirmation of successful overwintering in Texas, although it is possible there was overwintering in nearby Dawson County last year; the results were not conclusive. Results of 2016 High Plains overwintering trials are pending. As mentioned in a previous post, the aphids are moving northward much more rapidly than in past years.

Photo Credit: Crystal Alvarez and the students of Roscoe Collegiate High School.

We would like to express our thanks to these students; Crystal Alvarez, Kelsi Vrubel, Katelyn Collins and Matthew Buckley. We would also like to thank Roxanna Reyna-Islas, Extension Program Specialist 4-H, who worked with the students in conducting this trial.