June 2023

Note: There will not be a July iWire. See you in August.

Caterpillar Conga Line

If you ever see a parade of fuzzy caterpillars forming what looks like a conga line (one following another, head to tail, in a long continuous line), the following may be going through your head: Yes, I know, it’s pretty awesome! No, you should not touch them, even though the little kid inside your head kind of wants to (we will get into this more later). Is this normal behavior? Yes, it is. Why have I never noticed these before? If you are asking this while living in the U.S., then the answer is because you are looking at an invasive species. Those marching caterpillars will become processionary moths in the genus Thaumetopoea. This article will cover two important invasive species, oak processionary moths (T. processionea) and pine processionary moths (T. pityocampa).

Both species of processionary moths are covered in setae, or urticating hairs, which can cause skin irritation, asthma, and allergic reactions for people and animals. Although each of these invasives target a different host, the damage they do is similar. The caterpillars can strip a tree bare, reducing the trees’ ability to photosynthesize, weakening it and leaving it vulnerable to other threats.

Oak processionary caterpillars are black covered in white setae (hairs), while pine processionary caterpillars are orange-brown and hairy with blue bands. The adults are short lived, don’t feed, and are rarely seen in the wild. Adults of the oak processionary moth are small brown moths with a feathery pubescence along the thorax. The pine processionary moth is a bit bigger, with light brown forewings and brown crescent markings. Both species build a ‘tent’ on the side of the host tree where the larvae grow as a ‘community.’

Climate change and increased activity in trade routes have increased the stead of the oak processionary moth in England and the U.K. This moth has not yet been detected in the U.S or Texas, but its presence is regularly monitored through survey work via the USDA APHIS and partnering organizations.To learn more about the processionary moths look at these USDA APHIS datasheets: Pine processionary. Oak processionary.



 conga line of pine proc mothConga line of pine processionary moth (Thaumetopoea pityocampa). Credit: William M. Ciesla, Forest Health Management International, Bugwood.org.

oak process moth larvaeOak processionary moth larvae (T. processionea). Credit: Haruta Ovidiu, University of Oradea, Bugwood.org

Blasted Ballast Water

Ballast water is stored in a ship’s hull and is brought on board to manage the ship's weight, provide stability, and improve maneuverability. This is an important practice that reduces stress on the vessel, compensates for the weight shift that occurs when the cargo load changes, and can improve performance while navigating rough seas. Almost all sea-going vessels will take on some amount of ballast water. Unfortunately, bacteria, microbes, small invertebrates, and eggs or larvae of various aquatic species are also taken in with the ballast water and carried away from their original habitat. Ships drop off or pick up cargo from multiple different ports all over the world where they take in and/or release ballast water. This can create a mixture of organisms from several different ecosystems. When a cargo ship empties its ballast water at a port, the hitchhikers go with it, introducing potential invasive species. The introduction of aquatic invasive species can have a serious impact on the environment and on human health. For example, some species of toxic algae are transferred to new areas in ballast water and contaminate shellfish that is consumed by humans, leading to illness and death. Another example is the introduction of mussels that quickly spread and become established, such as zebra and quagga mussels (Dreissena polymorpha and D. bugensis) that cost the U.S. millions.

This is why it is very important to have a clear set of standards and procedures for management and control of ballast water. Ships are required to be surveyed, certified, and inspected to ensure that all ships meet the ‘D2 standard’. This standard specifies the maximum amount of organisms allowed to be discharged in the ballast water. This usually involves the installation or the assistance of a water management system to treat the water before it is dumped out of the vessel. This whole process can be very expensive. A group of scientists have developed a new method of sterilizing ballast water that costs significantly less than other methods available on the market ($300k vs $1-5 million). The new sterilization method uses a combination of ultraviolet rays and mechanical methods. The prototype technology meets the D2 standard and is believed to reduce the risk of biological organism release by at least 60%. The ballast water cleaning systems are currently designed to be a port-based sterilization station, but with time the design team believes it will be possible to make a ship-based sanitation system that shipping companies can install on their ships. At a reduced cost, multiple sanitation stations can be installed at ports. More sanitation stations at more ports could help decrease the risk of biological invasion caused by ballast water.

Read the full article: Ballast stowaways thwarted with water cleaning tech.

outflow-of-ballast-water-from-fishing-ship. PhilAugustavo. Getty ImagesOutflow of ballast water from fishing vessel. Credit: Phil Augustavo, Getty Images.

Filipino-made-ballast-water-system-mainShipboard personnel oversee a live demonstration of the Filipino made ballast water sanitation system. Credit: Benjamin Vallejo, Jr.


Kitty Controversy Continues

Believe it or not, cats are an invasive species. They were introduced to the U.S. with the European colonists. Since then, their numbers have quickly multiplied. This issue has always caused controversy because of the companionship and love many people find from our furry friends, but outdoor and stray cats are just as problematic as other stray animals (no matter how cute and sad their faces are on those darn commercials). Outdoor cats contribute to the death of an estimated 2.4 billion birds yearly. They are also known to eat or kill reptiles, mammals, and insects. Beyond that, increased populations, especially when clustered, can lead to human health issues. However, the most evident problem is their ability to reproduce quickly. Females reach sexual maturity and can become pregnant at 4 months old. A mother cat can become pregnant again about 4 months after her last litter. Cats have no native range, meaning they will roam and move freely, raising a litter and moving on to have another, or sticking around. Who knows. That is the life of a nomad cat. So, what can we do? We obviously can’t go out and adopt every stray cat we see walking through the street…

Trap-neuter-release (TNR) programs are now legally protected in many Texas communities. This too is causing some controversy, but many believe it is a beneficial step in the right direction.

What does this program do? In many areas, if you picked up a stray cat, had it spayed or neutered (sterilized) and then released it back where you found it (it’s home), you could be charged with a misdemeanor for abandoning an animal. With the TNP program, an individual can now release a cat after sterilization without the risk of being prosecuted for abandonment. Many communities’ resort to euthanizing stray cats that get picked up to manage large populations. Unfortunately, sometimes that ‘stray’ is someone’s lost kitty that gets picked up by mistake. These communities are also in favor of the TNR program. TNR is also more affordable than euthanasia.

Now for the controversy. This is not a fix-all, but what is? This only works if a significant percentage of the cat population is brought in to be sterilized so that the population can be managed. It is argued that releasing the sterilized cats will does nothing to improve the bird population or human health. However, the hope is that with time, as the population levels off, native species will have a chance to bounce back, and health risks will be reduced. Last but definitely not least. Many argue whether this is the best ethical treatment of these cats. I am in no way an authority and I usually don’t give my opinion in these articles, but I think this is a better option than killing them or sticking them in a small cage with several other cats. We caused this problem, it’s our responsibility to fix it. I’m sure there are better solutions but as always, dollar signs stand in the way. Cat owners, this is for you: It is important to spay/neuter their animals to help limit the number of ‘unwanted’ animals that end up in overcrowded shelters. There are many affordable programs available. Make sure your furry friends have a belled collar whenever they go outside.

stray cat. Rebekah D. Wallace. University of Georgia. Bugwood.org
Stray cat. Credit: Rebekah D. Wallace, University of Georgia, Bugwood.org

stray feeding kittens. Vikram2784 CC0 1.0
Inebriated stray cat feeding kittens. Credit: Vikram2784, CC0 1.0


HELP, I’m Citrus, And I Can’t Grow Up!

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 invasives@shsu.edu.

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

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.

Invasive Fungus in Cargo Shipment

An invasive fungus was found early this month while U.S. Customs and Border Protection was inspecting a cargo shipment of pacaya received at George Bush International airport, Houston, TX. Pacaya are the edible flowers of date palms originated in Guatemala. The fungus was found on the plant stems and identified by the U.S. Department of Agriculture to be Colletotrichum sp. (Glomerellaceae). This fungus can infect a wide variety of hosts. If it were to become established in the U.S. it would be particularly problematic to high value agricultural crops, such as citrus, strawberries, mangoes, and avocados. The cargo was restricted entry into the U.S. and eventually destroyed upon the importer's request.

Full Press Release.


pacaya with invasive fungus. us customs and border protectionPacaya stems with invasive fungus. Credit: U.S. Customs and Border Protection.

2023 AIS In Commerce Virtual Summit

Join the 3-hour summit set up to develop strategies to minimize risks posed by aquatic plants and pets in commerce. Expert presenters and panelists will share information on e-commerce, monitoring and inspection, labeling and recordkeeping, regulations and enforcement, voluntary industry standards, and outreach associated with plants and animals in trade. The summit will conclude with the launch of seven collaborative work groups to develop action items aimed to minimize the spread of aquatic invasive species in commerce.

July 25, 2023, 11am-2pm Pacific Time.
Register here.


AIS in commerce  

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:

  • July 19, 1pm- Using People Powered Restoration to Manage Invasive Species in an Urban National Park. REGISTER.
  • August 16, 1pm - Introduced Plant Pathogens Threatening North American Forests. REGISTER.




Emerald Ash Borer Watch

The presence of the invasive emerald ash borer (EAB, Agrilus planipennis) has been confirmed in Cooke County, TX. Several adult EAB beetles were collected in EAB traps as part of a monitoring survey by the Texas A&M Forest Service and confirmed by the USDA APHIS national lab. Cooke county has been added to the list of counties under quarantine by the Department of Agriculture (TDA). Quarantine is designed to slow the spread of insects by restricting the movement of ‘woody ash material’, because EAB is unintentionally transported on firewood and wood products. (Full Press Release)

Since 2016, EAB has been detected in the following Texas counties: Bowie, Cass, Dallas, Denton, Harrison, Marion, Morris, Parker, Rusk, Tarrant, Titus, Wise, and now Cooke.

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 their 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 pincer-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 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:

Grass Carp
(Ctenopharyngodon idella)

The grass carp (Ctenopharyngodon Idella), is the largest member of the minnow family. The body is oblong and covered in relatively large silver to olive colored scales that continue up to but do not cover the head, which is left smooth. There are three simple and seven branched rays on the dorsal fin. These freshwater fish can grow to weigh an average of 65 to 80 pounds. This species lacks the typical golden hue of common carps and has no barbels. Barbels are special sensory organs that hang like chin hairs off the nose or mouth of many fishes.

The ability to produce numerous eggs and grow rapidly allows the grass carp to invade and establish in new habitats easily. Unlike other carps, grass carps prefer to spawn in large rivers with turbid water instead of lakes or slower-moving water. However, grass carps can breed in slower-moving water if needed. This is potentially dangerous as larger rivers flow through many states and often split off to smaller water bodies, which can further the invasion rapidly with less human intervention/assistance. Grass carp do not typically migrate great distances and prefer to congregate in specific areas. Due to their physiological plasticity, grass carp can invade many different types of water habitats and consume various food sources. These fish are capable of consuming 40-300% of their body weight per day in plant material. This allows grass carp to quickly out compete indigenous species and disrupt ecosystems. Disruption most commonly occurs via algal blooms due to the increase of nutrients added to the water by the grass carp fecal matter. These carp only digest about half of the plant material they consume, the rest is expelled as waste. Algal blooms lower the water clarity and dissolved oxygen content. Grass carp also host parasites that local species may lack a resistance to.

Grass carp populations have been reported in 45 states. The only U. S. states free of reports are Alaska, Maine, Montana, Rhode Island, and Vermont. Many of the established breeding populations are from fish that have escaped from legal fishponds or as a result of illegal stocking. In Texas Grass carp are most often found in Lake Conroe, Trinity River, and the Galveston Bay area. Grass carp resemble many other carp species found in the U.S. For additional information, see the Texas Invasive species info page. If you believe you have identified a suspected grass carp, please email the location information, along with an image, to invasives@shsu.edu.

grass carp. Eric Engbretson. US Fish and Wildlife Service. Bugwood.org 
Grass carp (Ctenopharyngodon Idella). Credit: Eric Engbretson, US Fish and Wildlife Service, Bugwood.org
example of plant damage. USDA APHIS PPQ - Oxford. North Carolina. USDA APHIS PPQ. Bugwood.org
An example of a healthy plant compared to a plant damage by grass carp feeding. USDA APHIS PPQ - Oxford, North Carolina, USDA APHIS PPQ, Bugwood.org

note rays on dorsal fin.
Note distinct rays on dorsal fin. Different than similar carp species. Credit: Florida Fish and Wildlife Conservation Commission, Bugwood.org

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 texasinvasives.org 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. Texasinvasives.org 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 invasives@shsu.edu, 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 invasives@shsu.edu 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.

The Most Dangerous Plants You Should NEVER Buy from Nurseries
This video addresses many nursery plants you might not have known were invasive and lovely native alternatives. Please keep in mind different plants are native/invasive in different areas/regions and may require some additional research. If you like this video, there are more…

Everything You Need to Know About Kudzu And The Kudzu Bug
Enjoy this short sneak peek into the situation with Kudzu, the accidental introduction of the Kudzu Bug, and how neither one is likely going away any time soon.

The Truth About Invasive Species | Scishow Compilation
From worms to plants, mammal to aquatic, extremely harmful to not so bad, this video combines an exciting compilation of everything you could ever want to know about invasive species and why they are tricky critters.

More News

Beetles In a Bottle: A Message from Aliens to Schools
A recent study aims to increase public awareness of invasive species, and in this case, ambrosia beetles (Xyleborinus saxesenii), by having citizen scientists learn as they participate. phys.org

Texas Boaters Urged To 'Clean, Drain and Dry' Or Face Hefty Fines
With things warming up and people gearing up for water activities, TPWD would like to remind everyone to Clean, Drain, and Dry to avoid fines that come from transferring invasive aquatic species via boats, trailers, or other watercrafts. mrt.com

Seaweed Firm Aims to Turn Invasive Species into Food, Nutraceuticals
A collaboration of companies is looking to turn invasive seaweed species into usable produce and products. They hope to utilize Undaria sps. for its human consumption capabilities, nutraceuticals, and anti-cancer properties. teaomaori.news

Got Weeds? US Environmentalists Call in the G.O.A.T.S
A landscaping team of 150 goats was used to yank out weeds and remove invasive species from a Texas park. Using ruminants as an ecological way to care for land has become part of a growing trend. phys.org

Spearfishers Remove Nearly 20,000 Invasive Lionfish from The Gulf of Mexico in Two Days
Spearfisherman participating in the annual Emerald Coast Open Lionfish Tournament set an all-time record when they removed almost 20,000 invasive lionfish (Pterois volitans) from the Gulf of Mexico. fieldandstream.com

Attack Worm May Be New Biocontrol Weapon Against Wasp
The Sirex woodwasp (Sirex noctilio) pest kills trees by spreading a wood-rotting fungus. However, a recently discovered roundworm, called Deladenus siricidicola- Lineage D, has been discovered in an Australian pine forest and seems to be protecting the trees. phys.org

Discover The 3 Invasive Spiders Crawling All Over Texas
Read about the invasive spider species that have made their way to the U.S. and where you might encounter them in Texas. a-z-animals.com

Team Develops Autonomous Robot to Stave Off Spotted Lanternflies
A team from Carnegie Mellon University's Robotics Institute has developed an autonomous robot to control the spread of spotted lanternflies (Lycorma delicatula) by detecting and destroying egg masses. phys.org

Discover The 6 Invasive Ants Crawling All Over Texas
Six different species of invasive ants have been introduced to Texas in different ways and at different times, but they all have one thing in common. They are damaging to the ecosystem. Learn more about them here. a-z-animals.com

To Fight Berry-Busting Fruit Flies, Researchers Focus on Sterilizing the Bugs
Researchers have developed a method to sterilize the offspring of an invasive fruit pest called spotted wing drosophila (Drosophila suzukii) through genetic manipulation to manage populations. This may provide fruit growers a new tool to fight back. phys.org

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.