Insect Strip

Insect Strip

Wednesday, April 8, 2015

Sugarcane Aphid 2015 Distribution and Hale County Overwintering Site

Sugarcane Aphid (SCA) Current 2015 Distribution Map(s)
Dr. Robert Bowling, Extension Entomologist in Corpus Christi, has spent several weeks looking for sugarcane aphids this winter on Johnsongrass and sorghum from the Rio Grand Valley and even over to the San Angelo area. He has assembled maps that contain individual county records of when he found aphids and a composite map for the start of 2015 that are located at Texas Sugarcane Aphid News . As diligent as Dr. Bowling has been looking for the sugarcane aphid, we know there are still many counties that have not been checked and aphids may start to become active on Johnsongrass and any of the sorghum related plants as temperatures rise and plants start growing. Anytime you come across sugarcane aphids in counties that have not been reported for your county, please contact someone on the personal contact list of the Texas Sugarcane Aphid News, and/or collect some aphids in a ziplock bag or another container, let a contact person look at the aphids or take the aphids to your local county extension office. 

Sugarcane Aphid Overwintering Site - Hale County, TX

Mr. Blayne Reed, Extension Agent - IPM for Floyd, Hale, and Swisher counties and Dr. Pat Porter, Extension Entomologist - District 2, monitored the overwintering Johnsongrass site in Hale County for winter survival of sugarcane aphids. They found no surviving sugarcane aphids at the site yesterday. Last November the site was infested with sugarcane aphids and had a thriving population. At the site temperature recorders were used to monitor hourly the temperature at the soil surface and at a 4.5 inch depth below the soil surface. Details about the temperature data can be found at Texas Sugarcane Aphid News . This provides good evidence that sugarcane aphids did not successfully overwinter, at least from Hale Center to the Northern Texas High Plains. Many thanks are extended to Blayne and Pat for seizing the opportunity to monitor sugarcane aphids winter survival. 

Tuesday, April 7, 2015

Finding Grubs in Wheat?

This weekend I was out in my  yard at home and noticed some unusual holes in my flower bed. The holes were from birds digging into the soil to get a grub meal. Wherever I dug in the flower bed I would find grubs. So, I began to wonder if anyone has been having problems with them in any wheat fields.
We generally have issues with grub infestations in the fall, particularly, when fields are planted to continuous wheat for several years. In October of 2013, a field in Bailey county had a severe infestation which caused significant damage (note photo). Grubs this time of year are not a primary concern.
Fall wheat damage from grubs; Photo courtesy of M. Vandiver
But, with the warm temperatures and based on my flower bed infestations, grubs could be active near the soil surface and possibly cause damage until they pupate before emerging as adults in May and June. Also, there is a possibility if an infested wheat field is planted back to corn or grain sorghum this spring there could be seedling stand losses. If no damage symptoms are found now, egg lay activity of the May or June beetle could increase larval infestations and damage to early fall planted wheat, if not rotating or fallowing the field. The photo below illustrates the number of May or June Beetles that can be trapped in just one week with a Black Light trap. Beetles were captured in June of 2013 near Etter, TX.

May or June beetles captured near Etter, TX in June,  2013

 Even if you have an issue, there are no insecticides labeled for use against white grubs in wheat and depending on grub size seed treatments of Gaucho® or Cruiser® may or may not suppress the grub larvae. In times past, chlorpyrifos was once registered for grub control when chemigated, but it now only has a label for greenbug. Also, there would be concern about the pre-harvest interval if chlorpyrifos was chemigated.