Tuesday, August 15, 2017

One more Texas Panhandle County with Sugarcane Aphids

After reporting yesterday of sugarcane aphids in Moore and Sherman Counties, we received an email from Stephen Cox, crop consultant. He is finding sugarcane aphids in Hansford County. We appreciate everyones help letting us know about new findings of sugarcane aphids.

Monday, August 14, 2017

New counties added to the Texas Panhandle

I received a text today from Kaj Overstreet, crop consultant, that he has been finding sugarcane aphids in fields in Moore County. Then I received another text that he found sugarcane aphids in fields in Sherman County.

Also, last Friday, August 11th, I received a call for Mr. J. R. Sprague, County Extension Agent for Lipscomb County, that crop consultants found sugarcane aphids in a cotton field. I contact Dr. David Kerns, Texas A&M AgriLife Extension Cotton Entomologist, to determine if we should be concerned about sugarcane aphid in cotton. Besides Dr. Kerns being a cotton entomologist he worked on sugarcane aphids in sorghum while with LSU the past few years before coming back to Texas. He stated that sugarcane aphids could be found in cotton, but aphids were not able to survive to cause damage. The sugarcane aphid is indiscriminate as to where or what crops the alate (winged) aphids may land on. After a female aphid lands on a plant she will begin giving birth to live immature aphids.  Since cotton is not a sorghum related plant the aphids are unable to live very long. Therefore, sugarcane aphids should not be a threat to cotton, but other aphids do live and reproduce on cotton.

Wednesday, August 9, 2017

Sugarcane Aphids Found in Glasscock and Reagan Counties

Sugarcane Aphids Found in Glasscock and Reagan Counties

 

After first being detected in neighboring Tom Green County nearly 7 weeks ago, SCA has now finally shown up in both Glasscock and Reagan Counties. The timing is quite nice as most all of the sorghum in Glasscock, Reagan and Upton Counties is drying down and anywhere from days to a week or so away from harvest. There is a little late planted grain sorghum as well as haygrazer that will have to contend with the aphid, but for the most part St. Lawrence area sorghum will be harvested before economic damage can be inflicted on the crop.

 

 

Brad Easterling

EA-IPM

Glasscock, Reagan, Upton Counties

PO Box 299

Garden City, TX  79739

432-354-2381 (o)

940-256-1524 (m)

http://glasscock.agrilife.org/

https://www.facebook.com/stlawrenceipm/

 

Thursday, August 3, 2017

Aphids Unaffected by High Plains Rains, New Counties Added to the Map

The reports from downstate that discussed the relatively wimpy punch of sugarcane aphid this year, and the association of rain with that lack of punch, gave us hope that this week's rains on the High Plains would have the same effect. Unfortunately, I have to report that we have seen no evidence that the rainfall slowed down the aphids.

We have been monitoring several fields in Crosby and Lubbock counties for some time, and this week the aphid numbers are higher than last week - considerably higher in some places. At the Lubbock Research and Extension Center where we have had almost 2 inches of rain in a week over two events, the aphids have now exceeded the treatment threshold on pre-boot through soft dough sorghum.

There is still a chance that rain and high humidity will kick off the fungi that kill sugarcane aphids, but as yet there is no evidence this is happening. Even with the more humid days we have experienced of late, our average humidity is well below that in South Texas where the fungi were given credit for reducing aphid numbers.

The good news is that there are relatively fewer aphids coming in now than in past years, so fields are building toward treatment thresholds in a softer manner. The larger colonies on High Plains plants are beginning to generate winged aphids.

Brent Bean, Agronomist for Sorghum Checkoff, reported sugarcane aphids on sorghum in Parmer County today.  Deaf Smith County was also added to the map today. DeBaca County in east central New Mexico also has confirmed sugarcane aphids.  The official map has been updated to reflect these discoveries.

Friday, July 28, 2017

Additional Counties in the Texas Panhandle with Sugarcane Aphids

The crop consultant, Mr. Jess McGee, that found sugarcane aphids in a field in Donley County has now found sugarcane aphids in a field in Gray County. Also, Dr. Brent Bean, Director of Agronomy for the United Sorghum Checkoff Program, has been stopping and looking for sugarcane aphids while driving across the Texas High Plains today. He was unable to find any sugarcane aphids in any of the fields, except one forage sorghum field that was west of Canyon in Randall County. He only found one single colony after scouting the field for 30 minutes. Sugarcane aphids numbers are not very high in any of the report fields, but be these findings indicate any grain or forage sorghum field should be closely scouted for the presence of sugarcane aphids. If you discover sugarcane aphids in a field, please contact any of the individuals listed on this site that are contributors for the Texas High Plains.

Tuesday, July 25, 2017

SCA in Hale County

Greg Cronholm, Independent Crop Consultant and retired Extension IPM Agent, just called to report finding sugarcane aphid in Hale County about 3 miles from Plainview. Most were small colonies but some were a bit bigger. Similar to what we saw with the early infestations  in Crosby County last week, he said his colonies were in the upper ½ of the plant.

For the southern High Plains we now have sugarcane aphid confirmed in Crosby, Lubbock, Hale and Floyd counties. 

Sorghum Headworm Control: Consider Sugarcane Aphids

Sugarcane aphid is just beginning to build in fields in select counties on the Southern High Plains, and as of this writing I know of no fields that have required treatment. The sugarcane aphid distribution map can be found here. So far the aphids are building fairly slowly. This article is posted in the Sugarcane Aphid News site because sugarcane aphids should be considered if headworm control becomes necessary.

The less than good news is that fairly high numbers of headworms (corn earworm + fall armyworm) are being found in panicles. I was in a field in northeastern Crosby county last week that had 1-3 medium to large worms per head, and this field was later treated. Katelyn Kesheimer, IPM Agent in Lubbock and Crosby counties, just reported a field near Shallowater in Lubbock County that had a large number of worms. Stan Carroll, the Research Technician who runs the cotton bollworm/corn earworm traps at the Lubbock Center, told me this morning that he emptied the traps Tuesday night and had a high number of moths in them when he checked them Wednesday morning. We are therefore experiencing a big flight of cotton bollworms/corn earworms. The good news, if you can call it that, is that the fall armyworm trap captures are still well below average.

Insecticide selection for headworms is complicated now that we have sugarcane aphid or the threat of sugarcane aphid in the system. Most of our older insecticides like pyrethroids, Sevin, Lannate etc. will provide control, but they will also eliminate the beneficial insects from the field and leave it more open to damage by the sugarcane aphid. Newer insecticides like Blackhawk and Prevathon will preserve the beneficial insects, but they are more expensive than the older products. Besiege is a combination product; it has the same active ingredient as Prevathon but with a pyrethroid as well. Besiege will not preserve beneficial insects. If a headworm treatment is needed then the risk of sugarcane aphid will have to be factored into the choice of insecticides. As an additional complication, we think our corn earworm is still susceptible to pyrethroids in spite of some slippage downstate, but we know that fall armyworm is less susceptible to pyrethroids, especially the larger worms. One good thing is that headworms do not require the high gallons per acre of spray that sugarcane aphids do, so applications can be made with 3-5 GPA - but check the label for the specific product you intend to use.

Treatment thresholds are based on the size of the worms, number of worms per acre, heads per acre, control cost and value of the crop. For example, in the table below a treatment would be justified at 14,000 large worms (longer than 1/2 inch) per acre when the cost of control was $10/acre and the grain value was $7.00/cwt. To put this in perspective, if the field had 28,000 plants per acre, this would be one large worm per two plants. The online headworm threshold calculator is here.