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Saturday, April 29, 2017

Aphids and Fleahoppers


Cotton Aphid Mummies
Photo: Kate Harrell
Howdy,

  This week I saw very little in the field. One field near Palacios had high enough numbers of cotton aphids to warrant treatment, and I have heard reports of treatable aphid levels in the valley as well. 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.

 Cotton fleahoppers are cropping up around. Low numbers of them are present in all three counties. This insect feeds on plant materials, and will feed on cotton squares. Cotton is squaring in Jackson and Matagorda counties, as well as in the earlier fields in Wharton.  Keep and eye out for this insect, the adults are very flighty when checking your fields. I try not to let my shadow hit a plant before I look at it so I can see the adults before they fly. On the left, the adult is in the top photo, and the nymph on the bottom. The nymphs of these insects are also quite small, about the size of an aphid. They are also a pale green color, but lack wings. They nymphs can be easy to confuse with the nymphs of minute pirate bugs, but the minute pirate bug nymphs tend to be orange and are shaped more like a teardrop. Fleahopper nymphs lack the bands on the antennae a few other species of plant bugs have, and have a similar body shape to the adult bug.
  Fleahopper feeding will cause squares to drop. Plants can recover for and compensate for some square loss, but the threshold for fleahoppers is 15-20 per 100 plants.
  The chart below contains insecticide suggestions from cottonbugs.tamu.edu (also a good resource) for reference if you have fleahoppers at the action threshold.

Corn Leaf Aphids on Sorghum
Photo: Kate Harrell
  There are corn leaf aphids in some of the sorghum in Jackson county. So far we have not seen any need to treat for them. Sugarcane aphids are moving into the sorghum south of us, but I have not seen any in Jackson or Matagorda county yet. Please give me a call or send me an email if you see them moving into sorghum.

  Lovebugs are still everywhere. They are flies in the Bibionidae family, the adults do not bite, and the larvae are decomposers. They are a pain to get off the windshield. They have mating flights in mass, which is what we are seeing now. Dish soap can help get them off the windshield, but the longer they stay on the car the more difficult they are to remove, and the more likely they are to cause damage to the finish. Check out this website for more information on lovebugs.


  As always, contact me if you have any questions or concerns. Have a good weekend and good luck at the fair!

Kate

Saturday, April 22, 2017

Mud, Aphids, and Armyworms

Howdy,

  This week got muddy pretty quickly, and I didn't spend the amount of time I would have liked in the field. I saw some thrips in cotton, but not high enough numbers to treat. Threshold for thrips is 1 per true leaf until the cotton plant has more than 5 true leaves. There are also cotton aphids around. I haven't seen enough to justify treatment yet, but the agent in the valley (Danielle Sekula) has been getting incredibly high cotton aphid numbers in her area. I have been seeing cotton aphids in our fields as well, but not at the extreme numbers Dani has. Keep in mind that there would need to be 50 aphids per leaf before treatment would be warranted for aphids in cotton.

  The sorghum is looking good in Matagorda county. I did find sugarcane aphids on the edges of fields in Johnsongrass consistently in all three counties, but I have not seen them in the sorghum yet. If you do see them moving into sorghum, please give me a call and let me know so I can update our status on the national sugarcane aphid map. Danielle has reported sugarcane aphid numbers in the valley, and some of the growers have treated with Sivanto or Transform and gotten good control. Dr. Bowling mentioned that he has seen high numbers of corn leaf aphids in sorghum this year as well, from the Rio Grande Valley and into San Patricio county. It's been creating some confusion as to the differences between corn leaf aphids and sugarcane aphids. His photo of the corn leaf aphid is below. For more information on the aphid species, check out Dr. Bowling's website.

Photo: Jason Thomas

Photo: Kate Harrell


  Below are some photos of armyworm damage I found near Palacios. This damage was not near treatable levels. Armyworms and earworms are whorl feeders in this stage, and the "shotgun blast" pattern of feeding is typical. They chew through the leaves while they are still curled up in the whorl, which results in the "shotgun" type holes. Insecticide application may be justified if larval feeding reduces leaf area by more than 30 percent or is damaging the developing grain head or growing point within the whorl. Otherwise, it is better not to treat, especially given the potential to flare aphids with a pyrethroid treatment.

Typical Armyworm damage
Photo: Kate Harrell

Typical Armyworm damage
Photo: Kate Harrell

Armyworm
Photo: Kate Harrell
  Let me know if you have any questions or concerns, and please let me know if you see sugarcane aphids in sorghum. Have a good weekend, and good luck to all the 4Hers competing at the Wharton County Youth Fair in the coming weeks.

Sincerely,

Kate


Friday, April 14, 2017

Wind Damage

Howdy,

  We experienced some high winds recently. I am hoping this rain has helped with some of the moderately damaged plants. It should now be easier to see what will need to be replanted. Research shows that fields can still be considered viable with stand counts as low as 13,000 to 26,000 plants per acre, as long as they are evenly spaced. The seedlings that will survive are any that have a viable growth point. 

Dead seedling on left, two viable seedlings middle and right
Photo: Kate Harrell


Wind killed cotton seedling
Photo: Kate Harrell
  If the stem is crispy as in the above photo, the seedling will not survive. If it's burned, but the growth point is still intact as in the two photos below, the seedling should survive.

Wind damaged Cotton Seedling
Photo: Kate Harrell

Viable growth point on wind damaged cotton seedling
Photo: Kate Harrell

Severely wind damaged cotton seedlings
Photo: Kate Harrell
The seedlings in the photo to the left were severely damaged. The field I took this photo in will need to be replanted.

  Also, I have observed winged and wingless cotton aphids across all three counties. The cotton aphids rarely occur in numbers high enough to justify treatment. There would need to be 50 aphids per leaf before treatment would be necessary. In the fields with aphids, there were also high numbers of beneficials. Lady beetles, parasitic wasps, and disease prey on aphids. I've seen aphid mummies (from wasp parasitoids) and lady beetle larvae in several fields. The rains, heavy dew and humidity lately should also promote disease and fungal pathogens in aphid colonies. All of this can make a serious dent in aphid numbers rapidly.

  In addition, thrips are still around. Look for an average of at least one per true leaf before worrying about treatment. Once the plants pass the 5th true leave stage, thrips damage will no longer be a concern.

Winged Cotton Aphids
http://agrilife.org/mid-coast-ipm/2017/04/05/cotton-aphids-in-seedling-cotton/

  I have been checking on our sorghum variety trials as well as a couple of sugarcane aphid variety trials. There haven't been any sugarcane aphids move into the sorghum I've seen so far, but they are in the johnson grass in the ditches and edges of the fields. A&M is participating in a nation wide mapping project for the sugarcane aphid movement. I am only checking very few sorghum locations. If you see sugarcane aphids moving into sorghum, I would greatly appreciate it if you would contact me. Your input will help a great deal with this mapping project.

  As always, feel free to contact me with any questions or concerns. Have a happy Easter and a great weekend.

Sincerely,

Kate


Source articles:
http://agrilife.org/mid-coast-ipm/2017/04/05/cotton-aphids-in-seedling-cotton/
http://cotton.tamu.edu/General%20Production/Making%20Replant%20Decisions_2007.pdf

Friday, March 31, 2017

Thrips

Howdy,

  I am excited that cotton is up and growing in several places! At this stage, I am keeping an eye out for thrips. This is a small (about 1/15") light tan or straw colored insect with a punch and suck type mouthpart and asymmetrical mandibles. They punch a hole with one side, then siphon the juice out with the other. They feed one plant cell at a time, and march along punching and sucking as they go. The adults are winged, can travel short distances on their own, and can be carried by a breeze for a fair distance. Larvae hide on the underside of the leaves, often close to the leaf veins. Feeding damage for this insect causes the leaves to crinkle and curl, and can cause delays in plant maturity and eventual yield reduction.
Adult Western Flower Thrips
Kate Harrell
  While the insects are visible to the naked eye and scouting can be done just by examining the plant, it is easy to miss some of the smaller larvae. Smacking a cotton plant around on the inside of a cup will knock them off and can make them easier to count. This video Blayne Reed put together has techniques for scouting thrips as well. Cotton with a neonicotinoid seed treatment is usually safe from thrips for about 2-3 weeks after emergence. Seedlings in a sandier soil will lose the effects of a seed treatment more quickly than those in heavier clay soils. Rainfall can also impact how long the seed treatments are effective, the more it rains the shorter the amount of time the seed treatment stays effective.
  The economic threshold for thrips is one thrips per true leaf of the plant until the 5th true leaf stage. Once the plant reaches this stage, treatment for thrips is rarely justified. Check out the cotton insect guide at this website for more information.

 Please call or stop by the office if you have any questions or concerns, and check out our upcoming CEU opportunity in Corrie's news release below.

Sincerely,

Kate Harrell


South Texas Agricultural Symposium - April 18, 2017

By Corrie Bowen
County Extension Agent
Wharton County
A web-based producer training, or webinar, is scheduled for April 18, 2017 at the Northside Education Center in El Campo.  2 CEUs in the IPM category will be offered to Texas Department of Agriculture Pesticide License Holders.  There is no fee to attend this program.
Educational programs of the Texas A&M AgriLife Extension Service are open to all people without regard to race, color, religion, sex, national origin, age, disability, genetic information or veteran status.  The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating.  Individuals with disabilities who require an auxiliary aid, service or accommodation in order to participate in any Extension activity, are encouraged to contact the County Extension Office for assistance 5 days prior to the activity.

Registration will begin at 7:30 a.m.  Our first presentation will begin at 8:00 a.m. with Dr. Megan Clayton, Extension Range Specialist on The Use of Drones in Ranching.

Dr. Joshua McGinty, Extension Agronomist will deliver a Weed Management Update at 8:30 a.m.

Managing Sugarcane Aphid with Resistant Sorghum Hybrids will be the topic of Dr. Robert Bowling’s 9:00 a.m. presentation.  Dr. Robert Bowling is an Extension Entomologist in Corpus Christi, Texas.

At 9:30, Dr. Joe Paschal, Extension Livestock Specialist, will address a New Year – Old Pest: An Update of 111 Years of Fever Tick Control.
  
After a coffee break at 10:00 a.m., Dr. Megan Clayton will return to the schedule with a discussion focused on Setting Goals to Determine What to Plant in Your Pasture.

Mac Young, Extension Program Specialist-Risk Management will cover The Financial Truth Behind Planting your Pasture for Grazing Cattle at 10:45 a.m.

At 11:15, Herd Replacement Selection will be the focus of  Dr. Joe Pashcal’s second presentation.

And, the last presentation at 11:45 will help address  Determining What You Can Afford to Pay for a Replacement , by Mac Young.


The entire program will adjourn at 12:15 p.m.  Participants are encouraged to contact Stacey by April 17th at the Wharton County Extension Officer at 979-532-3310 to let us know that you’ll be attending.  A copy of the program flyer can be downloaded by visiting http://wharton.agrilife.org

Friday, March 10, 2017

Panhandle Wildfires

Howdy,

  We've gotten a fair amount of rain lately, and I know many of you have been planting between showers. Dr. Mcginty shared a couple of weed control guides that may come in handy. They cover a number of herbicides and when to use them. For the cotton guide, go to this website, for the sorghum guide, check out this one. The corn weed guide is currently under construction, but many of the same burndown herbicides in cotton can be used in both corn and sorghum (like Roundup, Gramoxon, Liberty, 2 4-D, Clarity, Valor, and Sharpen).

  The Texas panhandle has been in the news lately due to the wildfires raging all across the plains. I even saw a weather update advising residents to "beware of flaming tumbleweeds". The fires have destroyed homes, killed livestock and wildlife, consumed hundreds of thousands of acres of rangeland and cost human lives. Several producers in the panhandle have stood by this area when hurricanes and floods have accosted the region. If you would like to donate feed or funds to wildfire relief for the panhandle, please check out the flier below.


  Have a good weekend, everyone.

Sincerely,

Kate


Friday, February 17, 2017

Storm Damaged Trees and Fever Tick Map

Howdy,

  The tornadoes, high winds, and thunderstorms we've had around lately left the area with damaged buildings, vehicles, and trees. If you have damaged trees, make sure you keep a few points in mind when assessing the damage. 
  • Is the tree creating a hazard with any broken branches, the proximity to buildings and or power lines?
  • Aside from the storm damage, is the tree healthy?
  • Are major limbs broken? Has the leader (main upward) branch been damaged?
  • Is at least half of the crown (branches and leaves) still intact?
  • How big are the wounds in the tree? The larger the wound the longer it will take to heal.
  Once you've assessed your tree, make a decision. If it's a keeper, prune the broken branches, repair torn bark or rough edges around wounds, and let the tree begin to heal.
  • A mature shade tree can usually survive the loss of one major limb. The broken branch should be pruned back to the trunk, and large wounds should be closely monitored for signs of decay for the next few months.
  • Young trees can sustain a great deal of damage and still recover. If the leader is still intact and the structure for future branching remains, removed damaged limbs and allow the tree to recover.
  • Resist the temptation to prune heavily and remove only the damaged limbs to give the tree the best chance at survival.
  • If the tree looks borderline and is not an immediate hazard, don't be afraid to wait a little while to see what happens. Prune the damaged limbs and give it time to see if it recovers.
  When pruning a damaged tree, cut all damaged branches at the nearest lateral branch, bud, or main stem- not in the middle of the branch. If you can't save the tree, or the damage is too severe for you, contact an arborist for help.
  
  For more information on repairing storm damaged trees, visit these two websites I used for parts of this blog article- agrilife.org and texashelp.tamu.edu.

  Our livestock and veterinary extension entomologist shared the most recently updated map for those of you following the cattle fever tick outbreak. Please read over this newest report below.
  Give us a call at our office, send me an email, or stop by if you have any questions or concerns. Have a great weekend, everyone.

Kate Harrell

Thursday, February 9, 2017

Sulfoxaflor, Cattle Fever Ticks, and Twitter Texts

Howdy,

The growing season is almost on us, I know many of you are in the field either treating weeds or fertilizing currently. Once I start scouting again this season, I plan on using twitter to post short updates while I am in the field. If you do not follow me on twitter, or do not have a twitter, but would still like the updates, you can subscribe to text message updates on your cell phone. If you would like to receive the text updates, text "follow uppercoastipm" to 40404 on your phone, as shown to the right.


We recently received notice that sulfoxaflor (Transform) was granted the section 18 emergency exemption by the EPA for control of sugarcane aphid on grain sorghum again. Management of the sugarcane aphid would be increasingly difficult with only one option in our toolbox, it's good to know we'll have two options again.


I would also like to share the following update on the Texas cattle fever tick below.





Texas cattle fever ticks are back with a vengeance

Cattle fever tick quarantine road sign in South Texas.
(Texas A&M AgriLife photo)

by Steve Byrns, Texas A&M AgriLife Communications
COLLEGE STATION– Texas cattle fever ticks, which made Texas longhorns the pariah of the plains in the late 1800s, are once again expanding their range with infestations detected in Live Oak, Willacy and Kleberg counties, said Texas A&M AgriLife experts.
As of Feb. 1, more than 500,000 acres in Texas are under various quarantines outside of the permanent quarantine zone.
Dr. Pete Teel, Texas A&M AgriLife Research entomologist at College Station, said the vigilance and cooperation of regulatory agencies, namely the Texas Animal Health Commission and the U.S. Department of Agriculture and the Animal and Plant Health Service, in collaboration with the livestock and wildlife industries are needed to detect, contain and eliminate cattle fever ticks.
Because there is no cure for tick fever, a series of quarantine levels are used to prevent animal movement and the spread of a fever tick infestation, and to permit animal treatments for tick elimination. For an explanation of these quarantines see http://bit.ly/2jkqTNX.  For the current situation report, see http://bit.ly/2l3hhba.
“We’ve been responding to calls for several weeks now stemming from this outbreak,” said Dr. Sonja Swiger, AgriLife Extension veterinary entomologist at Stephenville.
“Most of Texas has been shielded from this problem for so long that there is little memory of what it took to be able to enjoy the benefit,” she said. “Now when producers are confronted with the issue without knowledge of the history and biology and risks associated with cattle fever, they are overwhelmed.”
Teel said the historic cattle drives from Texas to railheads in Missouri and Kansas in the late 1800s brought unwanted attention when local cattle died of a strange fever associated with the arrival of Texas cattle.
Southern cattle tick, Boophilus microplus. (Texas A&M AgriLife photo)


“Texas cattle fever was ultimately linked to ticks brought along by the Texas longhorns,” Teel said. “These ticks were appropriately named Texas cattle fever ticks, due to their ability to transmit a fever-causing agent from infected to uninfected cattle.”
By 1906, Teel said, it was determined these ticks and Texas cattle fever were found throughout 14 southern states and were limiting the economic development of the region. It was also discovered that procedures separating cattle from these ticks was essential to disease prevention and tick elimination.
“State and federal eradication programs with industry support began in 1906 and slowly eradicated the disease by eliminating these specific ticks from the eastern seaboard to the Texas-Mexico border, a task declared completed in the 1940s,” he said. “A permanent buffer zone was created and has been maintained ever since along the international border from Del Rio to the mouth of the Rio Grande to prevent re-establishment of ticks from Mexico where both ticks and pathogens remain.”
Since the 1970s, there have been periodic incursions of these ticks into Texas. One such incursion is happening now, requiring quarantine and eradication to prevent their spread, he said.
“Decades of changes in land-use, brush encroachment, expansion of native and exotic game, diversification of animal enterprises and variation in climatic cycles are contributing to new challenges in keeping this problem at bay.”“However, the success of this program has protected our cattle industry from the risks of disease outbreaks by preventing contact with the tick vector for so long that most people do not remember the tremendous effort and significant benefits, and are often unaware that this risk still exists,” Teel said.
Cattle tick in hand. (Texas A&M AgriLife photo)
How risky is the disease? Teel said the Southern Region of the U.S. is home to more than 400,000 cattle operations producing a third of all fed cattle in the country. This region is the original distribution location of these ticks before the eradication program, and climate modeling indicates it would still support these ticks today.
Mortality in cattle without prior exposure to the disease is estimated to range from 70-90 percent. There are no protective vaccines and no approved drugs to treat sick animals in the U.S., he saidThe U.S. Department of Agriculture has estimated that if eradication of these ticks had not occurred, cattle industry losses across the southern U.S. today would be about $1 billion annually.  
The technical name for Texas cattle fever is bovine babesiosis, a name related to the organisms that infect the red blood cells of cattle. It is their destruction of the red blood cells that results in anemia, fever and death, Swiger said.
“There are two closely related tick species capable of transmitting these pathogens, one called ‘the cattle tick,’ Rhipicephalus (Boophilus) annulatus, and the other called ‘the southern cattle tick,’ R. microplus,” she said. “Both of these tick species and associated pathogens were introduced to the Western Hemisphere on livestock brought by early explorers and settlers from different parts of the world.”
The origin of the cattle tick is the Mediterranean area where climates are relatively temperate, while the southern cattle tick is from the tropics of the Indian sub-continent. Thus, they were both successful in adapting to the southern climates of the U.S., as well as similar climates in Mexico, Central and South America, Teel said.
Teel said fever ticks remain on the same animal through their larval, nymphal and adult stages all the way through until the blood-engorged females drop off the host animal. Once off the host, females lay from 2,500-4,000 eggs, and then die. The males remain on the animal to mate with more females. It takes 20 days from the time the larvae arrive on the host animal until the first females start dropping off with the most females leaving the host at about Day 25. So, animal movement during this period allows ticks to be dropped into new locations.
“A successful hatch depends on moderate temperatures and high relative humidity more common to tree and brush covered areas than to open meadow or grass habitats,” Teel said. “If ticks pick up the pathogen from their host during blood feeding, the pathogen is passed through the egg to the larvae of the next generation. No other tick species in the U.S. are capable of transmitting the pathogen of Texas cattle fever.
“Cattle are the preferred host and back when cattle were basically the only host, the ticks were much easier to control,” he said. “Today white-tailed deer and several exotic ungulates including nilgai antelope serve as hosts. Nilgai, an imported exotic species that have naturalized in much of South Texas, are native to India and were historically noted as a host animal for the southern cattle tick in India. So what we’ve done is bring both the ticks and nilgai together again.”
While there are many challenges to optimizing tick suppression where there is a mix of cattle, wildlife and feral ungulate hosts, Teel said research and technology development are providing new tools to meet these challenges.
“AgriLife Research and the USDA’s Agricultural Research Service are collaborating to discover new and improved methods of detecting and eliminating cattle fever ticks,” he said. “These efforts include mining sequences of the DNA of both tick species to discover sites to disrupt functions such as tick feeding or egg laying, to identify targets for new pesticides, or genetic approaches for tick suppression or prevention of pathogen transmission.
“There is evidence that the manure of tick-infested cattle contains detectable differences in chemical makeup compared to non-infested animals and may provide for improved methods of tick detection,” he said. “And, the complex interactions of tick-host-habitat-climate relationships through simulation modelling are currently being investigated to improve tactics and strategies for tick elimination where both wildlife and cattle are involved.”
To learn more, Teel and Swiger recommend using Tick App, a free smartphone application available at http://tickapp.tamu.edu, and the Texas Animal Health Commission’s website at http://www.tahc.texas.gov/regs/code.html for information on tick treatment options, tick quarantine and associated regulations, as well as the latest updates on current quarantines.

Don't hesitate to give us a call or drop by the office if you have any questions or concerns.

Sincerely,

Kate