Extension News

Dagan Teague joins AgriLife Extension as integrated pest management agent

January 22, 2020 by Rob Williams

Excerpted from an AgriLife Today story by Susan Himes

The Department of Entomology and Texas A&M AgriLife Extension Service would like to welcome Dagan Teague as the newest integrated pest management in Floydada.

Teague started on January 2 and will serve Crosby and Floyd counties in District 2. Michael Clawson, AgriLife Extension district administrator, Lubbock, will be her supervisor.

“As the new IPM agent for Crosby and Floyd counties, Dagan will be a welcome addition to District 2,” Clawson said. “As an undergraduate at Texas A&M, Dagan worked for AgriLife Extension, and we’re excited to now welcome her to our team of agents.”

Teague has a bachelor’s degree in agriculture science with a minor in plant and soil science from Texas A&M University – Kingsville.

“I’m excited for this opportunity to work for AgriLife Extension and look forward to serving the people in my community,” Teague said. “I interned as a field scout down south and I loved being in the field looking for bugs – knowing it would help the growers at the end of the day. I also saw my boss Danielle Sekula, loving what she did, which inspired me to make this my career.”

West Nile case numbers lowest since 2012

September 6, 2019 by Rob Williams

by Adam Russell, Texas A&M AgriLife Communications

Aedes mosquitoes, a known vector of West Nile virus, and other diseases, are small dark mosquitoes with distinct white bands on the legs. (Texas A&M AgriLife Extension Service photo) — *Aedes* mosquitoes, a known vector of West Nile virus, and other diseases, are small dark mosquitoes with distinct white bands on the legs. (Texas A&M AgriLife Extension Service photo)

DALLAS COUNTY – Cases of West Nile virus in Texas have been the lowest in years, and researchers may know why, according to Texas A&M AgriLife Extension Service experts.

Dr. Mike Merchant, AgriLife Extension entomologist, Dallas, said a publication by health officials in Dallas County may shed light on factors that contribute to outbreaks and help forecast outbreaks in the future.

There has been one case of West Nile in humans this year in Fort Worth, but Merchant said vector indexes used to measure the conditions under which the disease is spread are the lowest they’ve been in five years.

Mosquito numbers this year are normal to high, Merchant said, but the presence of the disease has remained low. A report by the Dallas County epidemiologist showed West Nile virus outbreaks correlate with weather conditions, and this season was not conducive to its production and spread.

Prime conditions

Culex mosquitoes are the primary vectors for West Nile virus. Their preferred breeding grounds include standing water that seldom dries, the edges of ponds, lakes and smaller impoundments. (Texas A&M AgriLife Extension Service photo)

On the other hand, Merchant said conditions in 2012 were prime for spreading West Nile virus.

In 2012, nearly 400 cases of West Nile virus were reported in Dallas County alone, and 19 people died of the disease. The epidemic was so bad county officials resorted to spraying the entire county.

The paper, written by Dallas County epidemiologist Dr. Wendy Chung, and colleagues in 2013, explains the lower number of West Nile cases this summer, said Merchant.

Chung and colleagues charted the 2012 outbreak and found high infection rates of mosquitoes early in the summer, followed by a rapid increase in human cases.

Looking back over previous years and case numbers, Merchant said the researchers concluded that an unusually mild winter followed by rainfall patterns ideal for mosquito breeding in the spring followed by a very hot summer created ideal conditions for an outbreak.

“Mosquitoes breed faster when it’s hot, but also the virus multiplies faster at higher temperatures,” he said. “So, we had conditions for the worst year then. This year the heat didn’t really set in until the last month or so.”

Take precautions despite low case numbers

This graphic shows what items in the yard may trap water and provide mosquitoes with a breeding site. (Texas A&M AgriLife Extension service graphic)

Dr. Sonja Swiger, AgriLife Extension entomologist, Stephenville, said the rest of the state has also experienced a lower number of West Nile cases this year.

Swiger reached out to the state medical entomologist and entomologists in Dallas and Harris counties and said the consensus is numbers are slow at this time but that may or may not predict the year.

Case numbers have been lower than each year prior, she said, but the virus can peak when conditions allow.

“If you look at the data from the years before 2012, one of the largest WNV outbreaks on record, the cases were minimal just the year prior,” she said. “Plus, a weather event could still occur at any time and change what is happening now. WNV season does not conclude until Nov. 1, and with two months left, we just cannot be positive of the future.”

Merchant said health officials in Dallas County have found West Nile-positive mosquitoes, but their numbers have been very low, especially when compared to 2012. While he doubts a major increase in transfers to humans will occur, people should take precautions to avoid mosquito bites.

“We still need to treat mosquitoes with respect and take proactive measures to avoid them, but we wanted to give some good West Nile news for a change,” he said.

For a comprehensive look at how to reduce mosquito populations around the home and protect against bites, go to AgriLife Extension’s Mosquito Safari.

Ree Set to Retire After 30 Years with Extension

August 29, 2019 by Rob Williams

Bill Ree with his plaque. Photo by Rob Williams

The Department of Entomology recently celebrated Extension specialist Bill Ree as he announced his retirement on August 31 with a special reception on August 13.

Ree began his career in Extension in 1988 as an Extension Agent-IPM with a specialization in pecans. As an Extension Agent-IPM, Ree worked with pecan growers on protecting pecans from pests such as the pecan weevil. In 2007, he was promoted to Extension Specialist III – IPM where he was also responsible for working with pecan growers on pest issues.

Ree has been instrumental in developing and delivering information about pest management of pecans to growers by informing them about important pests that affect orchards in Texas, as well as in the southern and southwestern US.

Ree has also presented on the topic of IPM in pecans at several events in Texas, New Mexico and Mexico and authored and co-authored Extension publications on pests such as the pecan weevil, fall webworm, and pecan nut casebearer.

Ree is a member of the Entomological Society of America and the Society of Southwestern Entomologists. He received the Southern Region IPM Center’s Outstanding IPM Program Award and was a co-recipient of the Friend of IPM Educator Award in 2008.

“Bill has done such a great service to Extension and industry, said Associate Department Head for Extension Entomology programs Dr. David Kerns. “We’re going to miss him greatly.”

New research helps hay producers manage Bermuda grass stem maggot

August 1, 2019 by Rob Williams

by Adam Russell, Texas A&M AgriLife Communications

A clump of Bermuda grass shows damage by stem maggots. (Texas A&M AgriLife Extension Service photo by Shane McLellen)

OVERTON – A relatively new pest – the Bermuda grass stem maggot – is plaguing Texas hay producers this season, according to Texas A&M AgriLife Extension Service experts.

However, new research from Texas A&M AgriLife is helping growers better manage this pest.

“Previously, there was no information on how damaging this insect was to hay production and thus no guidelines on when an insecticide was needed to protect yields,” said Dr. Allen Knutson, AgriLife Extension entomologist, Dallas. “Our field research documented that for each percentage of stems with stem maggot damage, there is a potential loss of 8.9 pounds of hay per acre.”

Using data from fields in North Texas, Knutson and Dr. Forrest Mitchell, Texas A&M AgriLife Research entomologist, Stephenville, developed guidelines as to when an insecticide treatment is justified based on the cost of treatment and value of hay.

Dr. Vanessa Corriher-Olson, AgriLife Extension forage specialist, Overton, said she has received numerous phone calls and emails from producers and reports from AgriLife Extension agents in the region regarding the pest. She has also found them in hay and forage pastures at the Texas A&M AgriLife Research and Extension Center at Overton.

There was very little Bermuda grass stem maggot activity reported in the state last season, she said, but this appears to be a banner year for the pest.

“They’re definitely out there,” she said. “A few weeks ago, we had reports from Central Texas, but it’s not just there anymore. We can assume that if you have Bermuda grass in the state of Texas, you should be watching for signs of stem maggots.”

Feeding by the stem maggot causes the death of the top two to three leaves while the rest of the plant remains green. This gives a stand of Bermuda grass the appearance of frost damage. Also, the discolored top leaves are easily pulled from the leaf sheath, and plant growth is stunted.

“They’re typically not a major problem in grazing pastures because cattle are grazing those top leaves,” she said. “But they can cause serious damage in a hay meadow. The field will look like it’s been burned by frost, and stem maggot damage is often confused with a chemical burn.”

To use the new guidelines, it is necessary to estimate the level of stem maggot damage. To do this, Knutson advises cutting a handful of grass at the base of the stems and carefully examining 50 stems at random for stem maggot damage. Set aside those with the top two leaves dead and easily pulled from the sheath. Once 50 stems are examined, calculate the percent of damaged stems in the sample. Repeat this at five to 10 locations across the field and calculate the average percent of damaged stems for the field.

The new guidelines consider the cost of insecticide and the value of hay in determining when insecticide treatment is economically justified, Knutson said.

“For example, if the insecticide application cost is $12 per acre and the hay value is $140 per ton, the treatment threshold is 16% of the stems with stem maggot damage,” he said. “If the average field infestation is 16% or greater, an insecticide treatment should result in a positive economic return. If the control cost is $12 an acre, and hay value is $100 per ton, then the treatment threshold is 22% or more of the stems with stem maggot damage.”

In fields where stem maggot damage is already extensive, an insecticide treatment may not be sufficient to get the crop growing again, Knutson said, because damaged stems shade the lower nodes, preventing regrowth of new shoots. In this situation, the hay should be cut and removed as soon as possible to allow sunlight to stimulate regrowth.

A pyrethroid insecticide should be applied seven to 10 days after cutting to protect the regrowth from another stem maggot infestation.

“Weekly field inspection to determine the percent of stems with maggot damage can reduce the risk of significant yield loss and determine if and when insecticide treatment is justified,” Knutson said.

The Bermuda grass stem maggot is an invasive pest native to southern Asia and was first reported in Georgia in 2010. The pest has been found in Texas since 2012.

This pest only infests Bermuda grass and stargrass, Corriher-Olson said. The fly, which is yellow with a black head, lays its eggs inside the Bermuda grass stem. After the egg hatches, the larva, or maggot, which is white with a black head and 1/8th to 3/16ths inch long, moves to the last plant node and begins consuming the plant material within the stem.

Guidelines on managing Bermuda grass stem maggot and the table of treatment thresholds for a range of control costs and hay values are available online at https://foragefax.tamu.edu/.

Holly Davis Named Assistant Professor and Extension Specialist in Weslaco

July 26, 2019 by Rob Williams

The Department of Entomology and Texas A&M AgriLife Extension Service want to welcome Holly Davis as the new Assistant Professor and Extension Specialist for the Weslaco area.

Davis will begin her position in Weslaco on September 1. Before being hired by Texas A&M AgriLife Extension, Davis was a Research/Extension Associate at Kansas State University from 2015 to 2019. At Manhattan, she worked closely with Extension agents and specialists on providing viable recommendations to growers on pest control measures to lessen the impact of pests.

Davis also was co-owner of Protech Pest Management, where she planned, conducted and evaluated efficacy trials for different herbicides, fungicides, and insecticides. She also was responsible for contract negotiations, as well as employee recruitment, payroll and supervision duties.

As the Insect Diagnostician at Kansas State, Davis identified arthropods found in crops, homes, and gardens and communicated the information to KSU extension service constituents. She also has worked as a research assistant where Davis conducted various field pesticide efficacy trials and prepared and presented various presentations statewide.

Davis also has taught several classes while at Kansas State, including Animal Health Entomology and an online course in Economic Entomology in 2018. She also taught Economic Entomology as a classroom course, as well as Insect Pest Diagnosis.

Davis has served as a member of the Journal of the Kansas Entomological Society’s editorial board for 3 years, is currently the Secretary-Treasurer for the society, and was involved in various 4-H events from 2009-2016.

Davis has received numerous awards, including the Excellence in Undergraduate Mentoring Award from Kansas State Department of Entomology in 2017 and the Friends of Extension Master Gardener Award in 2012.

“I am very excited to become a part of the Texas A&M AgriLife system! I have worked in Extension Entomology for several years and I love what I do!” Davis said. “I am really looking forward to this new opportunity to collaborate with, and learn from, colleagues at the AgriLife Extension and Research Station as well as producers and all stakeholders throughout the region.”

She also wants to serve the Rio Grande Valley well and will be working with her stakeholders to solve the issues that are currently in the area.

“My ultimate goal is to serve the stakeholders in the Rio Grande Valley in the most effective way possible. I hope to work closely with commodity groups, producers, consultants, scientists, etc. to develop a good understanding of the key arthropod problems they are up against, and then plan to make use of all possible resources to help mitigate these issues,” Davis said. “I will also work hard to provide data-driven recommendations to stakeholders by any and all means necessary.”