Wednesday, September 16, 2020

Nootkatone Now Registered by EPA

Formulation of Nootkatone as Repellent and Pesticide Products Against  Mosquitoes and Ticks | Federal Labs

Nootkatone, from grapefruit, gets EPA approval for use in insect repellents 

A new active ingredient, discovered and developed by the Centers for Disease Control and Prevention (CDC), has been registered by the Environmental Protection Agency (EPA) for use in insecticides and insect repellents. Products are not yet out on the market but be looking for them in coming months. 

Studies show that when products are formulated from the new ingredient, nootkatone, they may repel and kill ticks, mosquitoes, and a wide variety of other biting pests. Nootkatone is responsible for the characteristic smell and taste of grapefruit and is widely used in the fragrance industry to make perfumes and colognes. It is found in minute quantities in Alaska yellow cedar trees and grapefruit skin.

Nootkatone can now be used to develop new insect repellents and insecticides for protecting people and pets. CDC’s licensed partner, Evolva, is in advanced discussions with leading pest control companies for possible commercial partnerships. Companies interested in developing brand name consumer products will be required to submit a registration package to EPA for review, and products could be commercially available as early as 2022.

“CDC is proud to have led the research and development of nootkatone,” said Jay C. Butler, MD, Deputy Director for Infectious Diseases. “Providing new alternatives to existing bite-prevention methods paves the way to solving one of biggest challenges in preventing vector-borne diseases—preventing bites.”

Studies show that when nootkatone is formulated into insect repellents, they may protect from bites at similar rates as products with other active ingredients already available and can provide up to several hours of protection.

Having a new effective ingredient for insecticide available will assist in addressing the growing levels of insecticide-resistance to other products currently in use, according to EPA.

“EPA is pleased to be continuing our partnership with CDC on registering nootkatone, which provides another tool to help protect the American public from biting insects and ticks,” said Alexandra Dapolito Dunn, EPA Assistant Administrator for the Office of Chemical Safety and Pollution Prevention. “This new active ingredient has the potential to be used in future insect repellents and pesticides that will protect people from disease. In many areas of the United States, mosquitoes have become resistant to currently available pesticides. A new active ingredient in our toolbox will help vector-control programs.”

Mosquito- and tickborne diseases are a growing threat in every U.S. state and territory. The number of reported cases of mosquito- and tickborne diseases doubled from 2004 to 2018. Tickborne diseases represent almost 8 in 10 of all reported vector-borne disease cases in the U.S. Increasing risk from these diseases means increasing demands on federal, state, and local health departments and vector control agencies.

CDC has partnered with Evolva since 2014. In 2017, Evolva was awarded a Biomedical Advanced Research and Development Authority (BARDA) contract with the key objective of advancing the development of nootkatone and nootkatone-based products for protection against mosquito-borne diseases, including dengue and Zika. This work has been supported with federal funds from CDC and managed by the Office of the Assistant Secretary for Preparedness and Response (ASPR), BARDA, under Contract No. HHSO100201700015C.

Tuesday, August 18, 2020

With Summer Comes Blister Beetles

The presence of blister beetles is always a cause for concern but even more so as a horse owner. Blister beetles contain a chemical, cantharidin, that when consumed by horses and other livestock, can cause illness and sometimes death.

Blister beetles are known to feed on flowers and foliage of a wide variety of crops including alfalfa, ornamental plants, potatoes, soybeans, garden vegetables and other plants. Immature stages feed on grasshopper eggs, live in solitary bee hives or are predaceous, depending on species. 

Adults can be found on flowers or infested crops. Blister beetles in alfalfa fields at harvest can be killed by the harvest machinery and incorporated into the baled hay. Cantharidin is a very stable compound and remains toxic even in the dead and dried blister beetles that may contaminate alfalfa hay. Since blister beetles often occur in large groups, or swarms, within a field, dead beetles can be concentrated in a small portion of the bales.


Care should be taken to not handle them. Never handle blister beetles preserved in alcohol because the cantharadin dissolves in alcohol and will cause blisters on the skin.

Cantharidin causes irritation of the lining of the digestive and urinary system in horses. The number of beetles that result in illness is variable and depends on the sex and species of blister beetle and on the age, weight, bred and general health of the horse. The estimated number of ingested beetles that would be lethal to a horse ranges from 50-545.

For more information visit:,mostly%20orangish-yellow%20with%20three%20black%20stripes%20on%20each

Friday, August 14, 2020

West Nile on the rise in DFW Area

The Texas A&M AgriLife Extension Service experts want Texans to be aware of a large rise in mosquitoes testing positive for West Nile virus in Dallas and Tarrant counties.

The state’s warm climate makes Texas a prime breeding ground for vector-borne illnesses, and recent weather conditions have only heightened the mosquito problem for many areas of the state.

“In Texas, our biggest mosquito-related concern is West Nile virus,” said Sonja Swiger, Ph.D., AgriLife Extension veterinary entomologist in Stephenville. “It has been found throughout Texas and the U.S., and even places that don’t normally have a problem like Miami have had cases in 2020. It’s just that kind of a year.”

The West Nile virus also produces symptoms in people that can be similar to some COVID-19 symptoms – fever, cough and sore throat. Anyone experiencing these symptoms should consult their doctor.

“If you think you might have contracted West Nile virus, get tested,” Swiger said. “Do not assume it is COVID-19.”

West Nile mosquito numbers on the rise

“We’re seeing numbers as high in some counties as we experienced in 2012 and that could be problematic,” explained Swiger.

“Tarrant County is currently the hotspot, so to speak, but Dallas County is also starting to see a rise in their number of infected mosquitoes and their vector index,” she said.

“Tarrant County is reporting 30% positive in some areas and 50% positive in the northeast section, which includes the cities of North Arlington, Grapevine, Watauga, Keller and North Richland Hills, to name a few.”

According to Dallas County Health and Human Services, for the week ending Aug.1, 40 mosquito traps tested positive for West Nile Virus. A total of 127 mosquito traps in Dallas County have tested positive to date for the year and there has been one human case reported.

The previous week, Tarrant County reported that 51 trapped groups, or pools, of mosquitoes tested positive for West Nile virus and that there have been 163 positive test pools for 2020 so far.

In 2012, Texas experienced its largest outbreak of West Nile virus in history with over 1,800 confirmed cases.

“Most of these victims reported they were bitten at home,” Swiger said. “So, it’s important that Texans be aware at all times and use repellents when necessary.”

When to worry

AgriLife Extension has identified 85 different species of mosquitoes in Texas, however people don’t need to worry about contracting West Nile disease from all of them – only Culex quinquefasciatus.

Swiger said without any heavy rains, the Culex quinquefasciatus population will continue to grow without chemical intervention.

“We cannot predict what the next few months will bring unfortunately, but if heavy rains are in the future, we would anticipate a decline in positives, as the mosquitoes would be washed away,” she said.

The mosquitoes that carry West Nile virus are night biters, Swiger said. People should be extra cautious when outdoors in the evenings and make sure screens have no holes and doors are kept closed at night and are properly sealed to prevent mosquitoes from entering the home.

Staying safe

“Repellents are a must and the only real way to stay safe,” said Swiger. “Use DEET, picaridin, IR3535 or oil of lemon eucalyptus, which may also be listed as paramenthane-3, 8-diol, on people over 3 years of age, to get adequate protection. These are the only ones tested with certainty to stop the disease-carrying mosquitoes.”

When you are outdoors in any area where there could be mosquitoes, it is wise to wear long sleeves and long pants. The tighter the weave of the fabric, the better protection it will offer from bites.

Mosquito basics

Male mosquitos feed only on nectar, unlike their blood-sucking counterparts. Females also feed on nectar but need blood for egg production.

There are species of mosquitoes that feed during the day and species that feed at night. That may be why it seems like there are so many mosquitoes out at dawn and dusk – during these periods, the day and night feeders may overlap.

Swiger said during the day, grassy areas with tree coverage are where mosquitoes like to be to avoid the hot sun. Mosquitoes are cold-blooded and can’t regulate their body temperature. That’s why on warmer days they seek shade and why they typically aren’t around when the thermometer dips below the mid-50s.

“People in the city may not even notice mosquitoes during the day,” she said. “But the species of mosquito that carries West Nile virus typically lives in more urban areas, so people in cities are more likely to contract West Nile virus and need to be aware.”

If you live in the country, you’ll typically encounter more mosquitoes during the day, especially when it’s wet, Swiger said.

“At night, no one is better off than anyone else when it comes to mosquitoes,” Swiger said. “Whether you live in the country, suburbs or a big city, you’ll have mosquitoes to contend with.”

Mosquitoes hibernate in the winter. Some mosquitoes spend their winter as eggs that then hatch when the weather warms up, while others hibernate as adults or larvae. Areas with a hot and humid tropical climate can experience mosquitoes year-round.

Mosquitoes and animals

Mosquitoes can transmit dangerous disease-causing parasites to dogs and horses too, including canine heartworms, Eastern equine encephalitis, EEE, Western equine encephalitis, WEE, and West Nile virus.

“We don’t see Eastern equine encephalitis much, but even one case is cause for concern, since the mortality rate for horses with EEE is 75-80%,” Swiger said. “We typically see cases in East Texas and can expect to have cases in horses again this year. But we haven’t seen a case in humans yet.”

Swiger also noted while there are currently EEE, WEE and West Nile vaccines available for horses, there are none for humans as yet.

Mosquito prevention

The first step in mosquito prevention involves finding and eliminating mosquito breeding grounds. Mosquitoes lay their eggs in or near standing water, so any stagnant water is a potential problem. Any place around the home or property where water can collect and sit for seven to 10 days is a problem to address.

Check property for standing water in clogged rain gutters, birdbaths, old tires, children’s play equipment, potted plant trays, tarps, holes in trees, bowls and buckets — literally anything that can hold standing water. Make sure to regularly change the water in any pet bowls outside.

Dump or drain stagnant water and turn over or cover items that catch and hold water. Gravel or sand can be used to fill places where stagnant water collects.

Wednesday, June 24, 2020

It is National Mosquito Control Awareness Week

While mosquitoes are an issue in Texas all year round, they are more of an issue in late spring, summer and early fall months. 

This week is a time to pay extra attention to mosquitoes and the locations where mosquito larvae will grow (buckets, pools, shallow non-flowing water, gutters, tires and debris). 

Did you know there are 85 species of mosquitoes in Texas that have been identified by Texas A&M AgriLife Extension Service’s agricultural and environmental safety unit personnel?
That’s a lot of itch-inducing painful pests to worry about. Besides being a buzzing and biting nuisance, mosquitoes carry a host of diseases and viruses that can be dangerous to people, pets and livestock.
“It’s a mosquito’s world, whether you see them or not, they are all around us.”
Our state’s warm climate makes a prime breeding ground for vector-borne illnesses, so AgriLife Extension experts hope Texans will observe Mosquito Awareness Week on June 21-27 by learning how to prevent and control these pests. Learn more at

a few Ways you can Protect against Mosquitoes:

  •  Drain: Empty out water containers at least once per week 
  •  Dress:  Wear long sleeves, long pants, and light-colored, loose-fitting clothing  
  •  Defend: Properly apply an approved repellent such as DEET, picaridin, IR 3535 or oil of lemon-eucalyptus 

For more information on mosquitoes and how to control them visit

Wednesday, May 27, 2020

Asian Giant Hornet

You’ve probably heard of the  Asian giant hornetor “murder hornet,” by now. It’s the world’s largest hornet. Native to Asia, it was sighted for the first time in Washington state and Canada in late 2019. Since then, additional specimens have been confirmed in May of 2020 from Langley, B.C., Canada and Custer, Washington. This suggests that this invasive hornet species has successfully overwintered in the United States and Canada. Keeping these insects out of Texas is important because they are formidable predators of honey bees, which are crucial for crop pollination.

Asian Giant Hornet

To learn more about the Asian Giant Hornet visit:

Thursday, April 30, 2020

Fly Season is Coming! - Stable Flies

Part 1 of "Fly Season is Coming!" (or for many, is here), there could be no other fly worthy of being first than the stable fly. Not only is it the FIRST biting fly to emerge for the year (or if you live in the south, stay active all year) it is also a nasty biter that will take advantage of any bloodmeal it can get.

The stable fly is the most significant pest of livestock in America; because of its painful bite and blood feeding behavior, cattle self-inflict stress and injury trying to escape attack.  The impact of the stable fly is noticeable with populations of more than 20 flies per animal, which can adversely affect animal health and significantly lower income for livestock producers.  Evidence shows that heavy infestations of stable flies on beef cattle have reduced weight gain by 25 percent and, in dairy cattle, have decreased milk production by 10 to 20 percent. 
To suppress stable flies effectively and economically, it is important to:
  • Be able to identify them properly;
  • Understand the insect’s life cycle; and
  • Use a combination of control strategies.


The stable fly, Stomoxys calcitrans, looks like the house fly, but it is smaller (14 inch). Unlike the house fly, stable fly mouthparts resemble a bayonet that can easily be seen protruding from the head.  The stable fly differs from the housefly in that it depends on blood as food and has an extremely painful bite. Stable flies primarily attack the legs of livestock and the ears of dogs.
An animal’s reaction to being attacked by stable flies consists of objectionable behavior such as stomping and kicking their legs, this makes it difficult to milk dairy cows.  Unrestrained animals will typically bunch together when attack, causing an increase in heat stress.  

Biology and habitat

The stable fly has a complete life cycle with egg, larval (maggot), pupal and adult stages. Populations can increase quickly: Under optimal conditions, the egg to adult cycle is about 3 to 4 weeks; therefore several generations can develop each year.  A female stable fly lives for 3 to 4 weeks and lays 500 to 600 eggs during its lifetime. 
The eggs are typically laid in wet straw, wet hay bales or in other decomposing vegetation mixed with urine and feces produced by the animals.


To suppress stable fly populations efficiently, producers should use an integrated pest management (IPM) approach. IPM relies on three tactics for successful suppression of an insect pest: cultural, biological and chemical. 
Cultural control: Cultural control methods involve manipulating the environment to reduce insect pest populations. The most economical and effective method for suppressing stable fly populations is sanitation.
In confined animal facilities, a top priority should be to eliminate stable fly breeding sites as often as possible. To do this, remove and spread decomposing vegetation or bedding material that has become mixed with urine and feces. Spreading the bedding will allow the material to dry faster and prevent colonization by the stable fly.
Another tactic for confined animal areas is to design the stalls to allow for complete manure removal and drainage. Cleaning out the wet feed remaining in the ends of troughs should be done weekly because the wet feed serves as a breeding site for flies. 
For small to moderate fly populations of adult flies, sticky traps and other mechanical methods, when combined with sanitation, are effective in confined areas. However, sticky traps will not substantially reduce fly numbers if used alone. Sticky traps should be changed weekly because they become coated with dust or “saturated” with flies.
Spreading decomposing vegetation (unused hay) should also be implemented for range or pasture cattle. Throughout the year, hay bales are often provided as supplemental feed for cattle. Over the course of the winter, the sites where hay bales have been placed become ideal stable fly breeding areas. Using hay rings will help to reduce stable fly populations in the field/pasture by reducing the amount of wasted hay trampled into the soil.  Also, moving the feeding site regularly reduces the accumulation of wasted hay at a site and eliminates breeding sites.  Spreading the accumulated wasted hay, will help dry out the site and prevent continual stable fly breeding.
Sticky Traps: The use of sticky traps provides a non-chemical approach to controlling stable flies, both males and females. The sticky traps are attractive to the adult stages as a resting location during bloodmeal digestion but prevent the stable flies from leaving. These traps can be used at any number of facilities but are best placed out of reach of animals. 

                                        Olson Biting Fly Trap           Knight Stick trap

Biological control: This IPM tactic uses natural predators (fire ants), parasites (like the wasp Spalangia sp.) or pathogens (Bacillus thuringiensis) to suppress pests. 
The parasitic wasp, Spalangia sp., is available commercially.  The wasp lays an egg into the pupa of the stable fly. The immature wasp feeds on the pupa, eventually killing the pupa.  The wasp develops into an adult and emerges from the pupa to start the cycle again.  
At this point, there is no clear answer to the effectiveness of using parasites to reduce fly populations.  Chances for success are greatest when coupled with waste and water management, and chemical control as needed.  Chemical controls should be limited to sprays or other application techniques that will not come in contact with breeding sites and kill the parasites.  Wasp releases have to be conducted on a set schedule and are needed each year; do not count on establishing a population on your farm.  Wasps may supplement an integrated program based on sanitation but are unlikely to provide adequate control when numerous breeding sites are available.  
Chemical control:
If a stable fly problem persists, an insecticide can be used. Many compounds are available for suppressing adult and larval stable fly populations. Always read the pesticide label in its entirety before making any applications.  
Animals can be treated as needed with sprays containing permethrin (Catron, GardStar, Permectrin II, Permethrin and Tengard), Ravap® EC (23% tetrachlorvinphos) and Vapona® EC (40.2% dichlorvos).  Residual wall sprays such as Atroban® 11% EC (permethrin), Demon®WP (cypermethrin), Ravap®, and Vapona® can be applied to surfaces where the insects rest. These products can be used in backpack or truck sprayers for range or pasture cattle or used in misters daily on dairy cattle for protection against stable fly feeding.  Brahman and Brahman cross cattle should not be treated due to hypersensitivity to organophosphates.  One day withdrawal is required for beef cattle sprayed with Vapona®.
Many premise products are available (Annihilator®, Atroban® 11% EC, Brute®, Demon® Max, Durashield®, Elector® PSP, GardStar®, Grenade®, Permectrin II, permethrin, Rabon® 50 WP, Ravap® EC, Tengard®, and Vapona®) that can be sprayed around a livestock facility and on side walls that are used as resting sites for fed stable flies.  Always follow product labels for conducting premise spray applications.

Friday, April 24, 2020

Vector CEU Classes in May

Continued social distancing requirements have caused the cancellation of all the in person Spring 2020 Vector CEU classes. But with unprecedented issues come unprecedented steps.  TDA has approved the extension of receiving CEUs for 2020 until December 31, 2020 and has also allowed us to move our CEU classes to web-based.
If you did not have time to attend one of the classes we held in April, we have two more scheduled for May.
  • May 6, 2020 - from 7:30 am to 12:30 pm, 5 hours of AG CEUs, 3 hours of SPCS CEUs, 5 hours of Animal Control CEUs, 5 hours of Registered Sanitarian CEUs and 5 hours of Code Enforcement CEUs
  • May 14, 2020 - from 12:00 pm to 5:00 pm, 5 hours of AG CEUs, 3 hours of SPCS CEUs, 5 hours of Animal Control CEUs, 5 hours of Registered Sanitarian CEUs and 5 hours of Code Enforcement CEUs
ALL must pre-register prior to receiving a link to the class. Registration is available at and limited to 100 people per class. 

Nootkatone Now Registered by EPA

  A new active ingredient, discovered and developed by the Centers for Disease Control and Prevention (CDC), has been registered by the Envi...