August 2023
Yellow-Legged Stranger

Yellow-legged hornets (YLH, Vespa velutina) have been found in Southern Georgia, the first time they have ever been reported in the U.S. During a collaborative monitoring effort involving state and government organizations, two living hornet specimens were collected. These specimens are believed to be from one or more nests that have not yet been found, but the search efforts are underway.

YLH are native to Southeast Asia and are known to be very aggressive toward honeybees, launching dive bomb attacks as bees leave their hive. This behavior has earned them the nickname ‘bee hawks.’ These hornets are typically smaller in size than native Georgia species, as they range from 1.2-3.0 cm (0.5-1.0 inch). They are best identified by the distinctive yellow tips at the end of their legs. They have a broad orange-yellow face with large prominent eyes. However, the head and body coloration can vary and may require a specialist for final identification. These hornets are categorized as a social wasp species that constructs egg-shaped paper nests in trees. These nests can be large, hosting as many as 6,000 workers.

It is believed the YLH were most likely accidently introduced to Georgia via a shipping container from the Port of Savannah, as it is one of the county’s busiest ports and the live specimens were collected on a property outside of Savannah. These invasive hornets attack and feed on a variety of insects, including bees, but their favorite food is fish. The Georgia Department of Agriculture and the USDA plan to put out feeding stations that will be monitored so that YLH can be tracked back to the nest(s) until they are all found and eradicated. This invasive species has the potential to put many pollinators and crops at risk if stable populations become established. The YLH has already spread to Europe, the Middle East, and parts of Asia where it is influencing the agricultural industry.

Read the Georgia Press Release.



 yellow-legged hornet. Allan Smith-Pardo. Invasive Hornets. USDA APHIS PPQ. Bugwood.orgYellow-legged hornet (Vespa velutina), lateral view. Credit: Allan Smith-Pardo, USDA APHIS PPQ,

size comparisonYellow-legged hornet (left) compared to Northern giant hornet, or Vespa mandarinia (right), dorsal view. Credit: Hanna Royals and Todd Gilligan, USDA APHIS PPQ ITP.

Space Matters During Battle

Many of us have seen first-hand how nature can be fierce, but if anyone has ever seen two ant colonies fighting over territory or resources, ‘fierce’ is not quite the right word for it. To literally compete to survive is unquestionably the most natural instinct for most organisms, next to reproduction.

A group of researchers have recently compared real-world examples of ‘ant battles’ to those of virtual gaming arenas using mathematical models from a virtual gaming simulation which allowed researchers to illustrate how battleground dynamics would illustrate ‘warfare’ outcomes. These concepts were then compared to real-world observations of Australian meat ants (Iridomyrmex purpureus), a native species that occurs in the research area, and smaller Argentine ants (Linepithema humile), an invasive known to many different places, including Texas.

Results of the study revealed, in both the virtual and real-life comparison, that when small armies of Australian meat ants come face to face with large armies of Argentine ants the mortality rate was lower in complex arenas, compared to simple arenas. Simple arenas likely had a higher mortality rate because Argentine ants can easily outnumber native ant species which becomes overwhelming in a small arena. Based on size alone, Australian ants easily beat Argentine ants in a one-on one. Battlefield complexity can tip the scales one way or the other, but there is much research left to do.

Read the research Lymbery et al.,2023

argentine ant. Eli Sarnat. PIAkey. Invasive Ants of the Pacific Islands. USDA APHIS PPQ. Bugwood.orgArgentine ant (Linepithema humile), lateral view. Credit: Eli Sarnat, PIAkey, Invasive Ants of the Pacific Islands, USDA APHIS PPQ,

 Iridomyrmex purpureus. Kalamunda. Perth. Western Australia. 2 Australian meat ant (Iridomyrmex purpureus), AKalamunda, Perth, Western Australia. Credit: Farhan Bokhari, AntWiki


Could Flies Fight Future Fires?

The recent fire in Maui was devastating and the cause is still under some debate. However, fields of untended non-native grass is believed to have contributed to the fast spread and wide destruction. Guineagrass (Urochloa maxima) is a common invasive field grass found on the island. It forms dense stands in open pastures and disturbed areas and can easily displace native vegetation. It is very drought resistant, meaning it can build up a dangerous amount of plant material, so when a fire occurs, the flames spread quickly and easily through the thick grass stands. Guineagrass is also fire-tolerant and can dominate ground area cleared by fire.

Hawaii is not the only place at risk to guinea grass and it is not the only place to has experience a fire in a grass-dominant landscape. Guineagrass has been reported in Arizona, California, Florida, Georgia, Louisiana, and Texas. Non-native grasses, such as this one, can help wildfire spread faster and farther. Due to this, Texas researchers are motivated to figure out what makes guineagrass thrive and what can be done to control the spread. One group of researchers hopes to find African gall midges, a type of flys that can be introduced as a biocontrol, targeted to eat or attack the guineagrass and leave the native grass alone. The study has so far found seven species, of which they believe some have true potential. However, biocontrol studies take time, and this research likely has another several years to go before any one biocontrol will have permission for official field studies. But hope is a wonderful thing and science is full of endless discovery. Read the article.

**Well wishes to any of those who lost loved ones or homes in the Maui fires, or any wildfires to date.

invasive grass fuel wild fire. HI state government. USDA
Depictions of invasive grass spesies known to fuel wildfires in Hawaii. Credit: Trauerrilcht et al., 2015, Hawaii State Government, USDA.

dry duineagrass. Dan Clark. USDI National Park Service.
Dry guineagrass. Credit: Dan Clark, USDI National Park Service,


Citrus In Your Backyard!

The Asian citrus psyllid (Diaphorina citri) and the Citrus Greening pathogen (Candidatus liberibacter asiaticus) are threatening citrus in multiple Texas counties, and we need your help to collect samples to monitor the spread to ensure that you and your neighbors are not affected. This pest and pathogen are extremely detrimental to Texas citrus, both economically and agriculturally. The presence of either can greatly affect citrus yield.

TISI is offering FREE diagnostic services! If you suspect your citrus has either the psyllid pest or the Citrus Greening pathogen, or you would like your citrus plants to be part of our screening survey, contact

We will send you all the instructions you will need. If you are located within 200 miles of our headquarters, we can collect samples, and/or provide traps and monitoring services ourselves. Not only will we share the results and management strategies (where applicable), but you will become part of a multi-county monitoring survey that is striving to improve the health of Texas citrus!

Also Available: TISI offers educational workshops that highlight information about the Asian citrus psyllid, the pathogen Citrus Greening, and what you need to look out for in your own backyard. If you are interested in this, TISI will provide trapping materials, assist with management strategies, and more. Don’t waste another second. Help us stop the spread!

symptoms of citrus greening. Jeffrey W. Lotz. Florida Department of Agriculture and Consumer Services.
Symptoms of citrus greening bacterium. Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services,

citrus greening
Leaf mottle on grapefruit, a characteristic symptom caused by citrus greening bacterium but also seen on trees infected by Spiroplasma citri. Credit: J.M. Bove.

Spotted Jelly in the Gulf

Another Australian spotted jellyfish (Phyllorhiza punctata), also known as white-spotted jellyfish, washed up on North Beach, Corpus Christi, TX, early July. These jellies have become invasive in the Gulf of Mexico in great number over recent years. They were first reported in Galveston, TX, in 2006. Spotted jellies can grow to reach 20 inches in diameter and travel in large groups. They compete with fish and shrimp for food as they consume large quantities of zooplankton and larval fish. A single spotted jellyfish can clear 50 cubic meters of plankton filled water in one day, greatly altering the water column and local wildlife. Read Press Release


spotted jellyAustralian spotted jellyfish (Phyllorhiza punctata) that washed up on North Beach, Corpus Christi, TX. Credit: Padre Island National Seashore.

Zebra Mussel Watch

The Texas Parks and Wildlife Department has recently found Zebra mussels (Dreissena polymorpha) veligers in the International Amistad Reservoir in the Rio Grande basin along the Texas-Mexico border near Del Rio. Veligers are the final larval stage of certain mollusks. Quagga mussel (D. bugensis) larva were detected in multiple places throughout Lake Amistad early last year. Due to these results, the lake has been designated “positive” for both zebra and quagga mussels. Positive status indicates invasive mussel larvae have been repeatedly detected, but no juveniles or adults have been found and there is not yet evidence of an established population. Past quagga press release.

Quagga mussels are closely related to zebra mussels and cause many of the same problems, which are present in well over 30 lakes across Texas. Although within Texas, quagga mussels are only currently present in Lake Amistad, they are present in other areas of the US, so there is a risk that boats can transport them to other Texas lakes. Quagga mussels can develop larger populations and infest deeper lakes. As seen in Lake Amistad, a waterbody infested with one invasive mussel is still susceptible to infestation by another. The department emphasized the importance of continued help from boaters, marina operators, and others to Clean, Drain and Dry all boats and water craft equipment before moving them, and remain vigilant to stop the spread of aquatic hitchhikers.

Anyone who spots quagga or zebra mussels should immediately Report It!.



mussel signal fltCredit: KNKleiner, TRIES.

North American Invasive Species Management Association Training Webinars

This program is designed to provide the education needed for professionals and students who are managing or learning to manage invasive species. The courses include the most current invasive species identification, control, and management techniques, and how to comply with local and federal regulations.

Participants may register and enroll at any time, and will receive a certificate of invasive species management from NAISMA upon completion of the program.

All live webinars are open to the public. Recorded webinars are available to members of NAISMA.

NAISMA 2020 Webinar Schedule:

  • September 20, 1pm CDT- Reviewing the Impacts of Climate Change on Biological Control Agents. REGISTER.
  • October 4, 1pm CDT- Utilizing Invasive Plants as a Medium for Conservation Artwork. REGISTER.
  • November 15, 1pm CDT- Decades-Long Partnership Successfully Eradicates Destructive Nutria Rodents from Maryland. REGISTER.




Emerald Ash Borer Watch

Emerald ash borer (EAB, Agrilus planipennis) has recently been detected in Cooke County, TX. Several adult beetles were collected in the county in an EAB trap that is part of a state monitoring program run each year. EAB is also classified as an infestation in the following Texas Counties: Bowie, Cass, Dallas, Denton, Harrison, Marion, Morris, Parker, Rusk, Tarrant, Titus, and Wise. The EAB was first detected in 2016, in Harrison County, TX, and was found through trapping efforts in Cass and Marion Counties the following year, with all 3 counties upgraded to infested level by 2018. By 2020, Bowie County was also added to the list of infested Northeastern Texas Counties. While EAB was spreading in northeast Texas, it jumped to Tarrant County with the first confirmed report in 2018, posted by a young student through iNaturalist. Since its initial sighting in Tarrant County, the beetles were subsequently found in Denton County, May 2020. The infestation has caused millions of dollars of damage to ash trees annually, and is present in 35 states.

The emerald ash borer is a metallic emerald-green beetle with iridescence that creates an almost brassy to coppery or reddish reflection. The adult beetle is bullet shaped (10-13 mm) and has a characteristically bright red to purple coloration on its abdominal surface under its wings (elytra). One external sign of EAB infestation is the distinctive D-shaped hole adult EABs leave in the trees upon emergence. The larvae are white, and slightly flattened, with a pair of brown pincher-like appendages on the last abdominal segment. The larvae (1.5 in) feed on the phloem and outer sapwood of ash trees, leaving S-shaped galleries that cut off the circulation of the phloem to the tree, resulting in tree death.

If you believe you have seen an emerald ash borer, please take a picture and REPORT IT!




EAB Watch- kkCredit: KNKleiner, TRIES.

Invasive Spotlight:

Chili Thrip
(Scriptothrips dorsalis)

Chili thrips (Scirtothrips dorsalis) are very small, approximately 1 mm in length, about half the size of most other flower thrips. The adults are pale yellow with dark wings and dark bands across the abdomen. Thrips, from the order Thysanoptera, are so small they are often overlooked and can be very difficult to identify at any life stage without a microscope. Thrips pupal and larval forms are very typical looking compared to other insects when they are at these life stages and require an authority for proper identification. The entire lifecycle is complete within 14-20 days. A single female is capable of laying upwards of 60-200 eggs, which only take 6-8 days to hatch.

These thrips have more than 100 recorded hosts, some of which include strawberries, tea, citrus, cotton, soybeans, chilies, castor beans, peanuts, and roses. Unlike other flower thrips who prefer to feed on pollen, chili thrips are polyphagous, meaning they feed on many kinds of food. They have piercing and sucking mouthparts. Chili thrips feed by extracting contents of individual epidermal cells, which leads to tissue necrosis and discoloration. Feeding scars, distortions of leaves, and discolorations on young leaves, buds, and fruits are common due to this feeding behavior. A very severe infestation can result in complete crop loss.

These thrips have been intercepted at the port many times over the decades. Infestations have been reported in Florida and southeastern Texas. Biocontrol agents are known and reported to be effective. For additional information about chili thrips and management information, see the Texas Invasive species info page. If you believe you have identified a suspected chili thrips, please email the location information, along with an image, to

female chili thrips. Andrew Derksen. USDA-APHIS. 
Female chili thrips (Scirtothrips dorsalis), dorsal view. Credit: Andrew Derksen, USDA-APHIS,
chili thrips damage. Florida Division of Plant Industry. Florida Department of Agriculture and Consumer Services.
Example of chili thrips damage. Credit: Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services,

Get Involved Today!!

The Texas Invasive Species Institute (TISI) and The Texas Research Institute for Environmental Studies (TRIES) have many surveys and projects underway. These facilities strive to provide yearly invasive species presence and absence data to the authorities. Pre-screening is one of the first lines of defense in the war against invasives. However, sometimes it is hard to do it alone.

With the aid of the public and citizen scientists, we could cover a much wider area, and gather a more substantial amount of data. When it comes to protecting our environment, there is an opportunity for everyone! Together we can make a difference, one research project at a time.

See how you can get involved by reading the projects listed below or see all the available projects on the Texas Invasives website HERE.

Aquarium Watch: Looking for Prohibited Invasive Aquatic Species

Please help and natural habitats by looking for 14 prohibited or invasive aquatic species that might be for sale in your local aquarium store(s). With just one photo you can assist us in finding and documenting which stores are selling prohibited or invasive species. will use this information to contact the appropriate Texas institutions to ensure the appropriate steps are taken for each case.

If you would like more information please email, and mention you want to assist with our Aquarium Watch.

Air Potato Survey

Help Texas Research Institute for Environmental Studies conduct an air potato survey by actively reporting any infestations seen in your area. The air potato (Dioscorea bulbifera) is a fast growing, high climbing vine. Potato-like tubers are the primary means of reproduction for this vine. They can be as small as a marble or as large as a softball. Native yams are often confused for air potatoes. To avoid this confusion, please refer to the key below:

- Plants rhizomatous; bulbils never produced in leaf axils; petiole base never clasping the stem; Native D. villosa
- Plants tuberous; bulbils produced in leaf axils; petiole base sometimes clasping the stem; Invasive D. bulbifera

For additional information, please refer to the TexasInvasives information page.

If you believe you have identified an air potato vine, please email and include the following information: an image, an approximate number of vines present, the location (including whether it is on public or private land), and if bulbils are present (the potato-like tubers that emerge from the stem).

Participation opportunities
Participation Opportunities. Credit: KNKleiner, TRIES.

Armorded catfish. Photographer United States Geological Survey
Armored catfish (Hypostomus plecostomus). Credit: United States Geological Survey.

air-potato (Dioscorea bulbifera)2 bulbil. credit Karen Brown
Air-potato (Dioscorea bulbifera), bulbil emerging from leaf axil. Credit: Karen Brown.

Video Invasion

As a new segment, we are shinning the spotlight on some amazing videos about invasive species and the people that choose to work with them. There are some amazing citizens and professionals around the world that pock, prod, chase, dive, and investigate everything they can about these alien invaders. We all have the same goal, learn as much as we can to restore ecosystems and preserve our native species.

Zebra Mussel Facts: more than an INVASIVE species. Animal Fact Files.
This short video summarizes the main facts about zebra mussels without any preaching. Learn the basic benefits, biology, and morphology before they were so hated.

Why Should I Care? Invasive Species: Plants
Walk through the woods with an authority on plants and wildlife as he points out non-native invasive plant species that are growing right before your eyes. He shows natural examples of what simple invasives can do on even a small scale and why these issues are important.

Why Invasive Tadpoles Turned Cannibal | SciShow News
Cane toads are invasive to Australia and in their non-native habitat some cane toad tadpoles are known to cannibalism each other. This behavior is not seen in their native range. Why is that?

More News

These Giant Rats Once Took Over a Fort Worth Park. Are They Still a Problem in Texas?
Nutria (Myocastor coypus) can be found throughout the eastern two-thirds of Texas around aquatic habitats, but the authorities believe their populations are on the rise.

Texas A&M Overton Plant Expert Discusses Invasive Kudzu
Kudzu (Pueraria montana var. lobata) can be seen growing up power poles and native vegetation along the roadside of east Texas. Listen to an expert talk about how it got to Texas and what we know about the fast-climbing plant.

Study Reveals Successful Strategies for Removing Invasive Caimans from Florida Everglades
The spectacled caiman (Caiman crocodilus) is an invasive species introduced to the everglades that poses a threat to the native wildlife. Response and removal efforts reveal optimistic results.

Biodiversity Protects Against Invasions of Non-Native Tree Species, Study Finds
Studies suggest that proximity to humans, especially maritime ports, drive the likelihood of invasions. However, biodiversity can help to buffer the intensity of invasive spread.

‘FRANKENFISH’: Invasive Fish That Can Survive Out of Water for Days, Caught in Missouri
Northern snakeheads (Channa argus) were caught in southeastern Missouri for the first time in four years. These fish can cause damage to water beds and have been known to bite humans who approach a guarded nest.

Q&A: Researchers Track New Invasive Insect, The Elm Zigzag Sawfly
The elm zigzag sawfly (Aproceros leucopoda) was first detected in the U.S. in 2021, and Canada in 2020. Since its accidental introduction, it has spread to five east coast U.S. states.

Japanese Beetles Could Spread Throughout Washington State In 20 Years
Japanese beetles (Popillia japonica) have spread across much of the U.S. and a recent study suggests without intervention this spread could continue. Quarantines and intense efforts could be the solution.

Research Identifies Moths That Slow the Spread of Invasive Fern
The old invasive climbing fern (Lygodium microphyllum) is spreading across southern and central Florida. Researchers that have been looking for a solution to slow the fern’s spread may have found a biocontrol.

Brown Widow Spiders: Invasive Species Prosper in Favorable Habitats and From a Lack of Local Predators
Research suggests lower levels of parasitism and predation in urban habitats may contribute to the invasive success of brown widow spiders (Latrodectus geometricus), especially when compared to desert white widow spiders (L. pallidus).

Invasive Firestarter: How Non-Native Grasses Turned Hawaii into A Tinderbox
Invasive grasses can be very “ignitable,” more resilient to fire compared to native species, and can replace native species that were wiped out during the blaze.

Sentinel Pest Network and Invaders of Texas Workshops

Invaders of Texas workshops train volunteers to detect and report invasive species as citizen scientists. Workshops, which are free, are designed to introduce participants to invasive species and the problems they cause, cover aspects of invasive species management, teach identification of local invasive plants, and train participants to report invasive plants using the TX Invaders mobile application. The workshop is 7 hours long (usually on a Saturday, but scheduling is arranged with each individual host group). The workshop satisfies Master Naturalist training requirements.

Sentinel Pest Network workshops serve to increase the awareness and early detection of a set of particularly important invasive species to help prevent their spread into Texas or their further spread within Texas. Participants learn to identify species such as the Emerald Ash Borer, Cactus Moth, Asian Longhorned Beetle, and other pests of regulatory significance, and to report them. The workshop is 3.5 hours long. The workshop satisfies Master Naturalist training requirements.

Upcoming Workshops:


CITRUS WORKSHOPS: Stay tuned for upcoming 2023 virtual weekend presentations about Citrus diseases and FREE testing we offer at Texas Invasive Species Institute.