June 2022
Fruit Flies Are After Texas Citrus

The Mexican fruit fly (Anastrepha ludens) is threatening Texas citrus crop. The US Department of Agriculture’s Animal and Plant Health Inspection Services (USDA APHIS) is asking the industry and residents to help protect and maintain Texas citrus from the invasive pest and the diseases it transmits, such as citrus canker and citrus greening. This invasive fruit fly threatens more than 50 agricultural fruits and vegetables in Texas, especially in the Rio Grande Valley, and across the U.S. The primary hosts are grapefruit, sweet and sour orange, key limes, and sweet lemons.

The Mexican fruit fly originates from Central America and Mexico. The adult is a pale orange-yellow with 2-3 whitish stripes along the thorax. The wings are clear with several yellow and brown stripes. Female fruit flies lay their eggs inside ripening fruit. The larvae hatch and eat the flesh of the fruit, causing it to rot. Larvae feed while tunneling through the interior of infested fruits, making the fruit unfit to eat. Microscopic organisms invade these injured areas causing internal decay of the fleshy portions of the fruit. USDA APHIS Fact Sheet

The citrus industry in Texas is a $67 million source of revenue for the state; therefore, the introduction of this fruit fly would be beyond devastating. The USDA APHIS and Texas Department of Agriculture (TDA) are partnering up to create quarantine zone where they will work with home and landowners to prevent the speed of this detrimental pest. APHIS employees in Cameron, Hidalgo, Willacy, and Zapata County are working with the TDA to inspect and survey fruit trees on residential and commercial properties for signs of invasive fruit flies and/or citrus diseases. In areas where fruit flies have been detected, residents and business owners have/will be asked to help limit the spread by cooperating with the survey team and allowing them to access the property and hang traps and/or conduct treatment.

Here are some tips to protect their fruit:

1. Remove mature citrus fruit/host material, including fruit on the ground, from your property ASAP.
2. Eat the fruit or double bag it and put it in the trash.
3. Don’t compost fruit/vegetables from the quarantined areas.
4. If you live in a quarantine area double bag the branches and other debris and dispose of them with your household waste.
5. Don’t move or mail homegrown fruit or plants outside of the quarantined areas.
6. Declare agricultural products to US Customs and Border Protection before entering the US from another country.
7. Be cautious purchasing fruit from social media or backyard vendors.



 Mexican fruit fly. Jack Dykinga. USDA Agricultural Research ServiceMexican fruit fly (Anastrepha ludens) on citrus. Credit: Jack Dykinga, USDA Agricultural Research Service, bugwood.org.

mexican fruit fly larvae. Florida Division of Plant Industry. Florida Department of Agriculture and Consumer ServicesMexican fruit fly larvae in citrus mash. Credit: Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, bugwood.org.

citrus greeningPathogen called citrus greening that damaged citrus plants.

Brighter Than Ever

Invasive species often colonize new environments and display behavioral change different to those of their native habitat. One such example of this is the Jackson's three-horned chameleons (Triocerus j. xantholophus). In 1972, a crate of Jackson's chameleons was shipped from Kenya to the Hawaiian island of Oahu destined for the pet trade, when they escaped into the surrounding area (click here to read the whole story). The island lacked predators, which allowed the chameleons to settle in and the subsequently population became an unplanned experiment in evolution. It was later found that the Hawaiian chameleons displayed much brighter social signals than individuals from their native habitat.

To test this, researchers presented male chameleons with a rival male, a female chameleon, a model bird predator and a model snake predator. These tests were performed in a one-on-one interaction. During the presentations they measured the Hawaiian chameleon color using an optic spectrometer. The optic spectrometer measured how colorful or bright they were. They then estimated how detectable the chameleon would be to another chameleon, bird or snake. They also measured the leafy vegetation in the backdrop so they could estimate how detectable a displaying chameleon would be against a particular background.

The results indicated Hawaiian chameleons displayed brighter social color signals than Kenyan chameleons during male contests and when courting females. Hawaiian chameleons were less cryptic in response to bird and snake predators and were more conspicuous against Hawaiian backgrounds than Kenyan backgrounds. These differentiations are likely due to local adaptation. Hawaiian chameleons also had a greater capacity for color change than Kenyan chameleons. This degree of color change could be due to plasticity.

Read the research: Whiting et al, 2022

Whiting et al 2022 copyJackson's three-horned chameleons (Triocerus j. xantholophus) color signal change in response to different social stimuli. Male chameleons experience intense sexual selection. See link at end of article to differentiate meaning of A-D. Credit: Whiting et al., 2022.

sciadv.abn2415-f2Mean spectral reflectance curves for male chameleons for representative body regions (gular and top flank) and background (leaves) for Hawaii and Kenya. See link at end of article to differentiate meaning of A-D. Credit: Whiting et al., 2022.


I Think You Will Like This Virus

I think it’s safe to say that everyone in Texas is familiar with fire ants. This is not the first time this newsletter has mentioned them and it is likely not the last. But in case you need a refresher, Solenopsis invicta, or the red imported fire ant (RIFA) is a very invasive, hard to eradicate, annoying pest ant, that is making its way across the U.S. and especially Texas (click here to read more). Texas does have native species of fire ant, however, they are often displaced by Solenopsis invicta, so it is likely that this is the species that you have in your yard. But there is some good news and some bad news. A few resent studies have been tinkering with viruses that may rid us of our fire ant problems, or they may not.

The first virus is Solenopsis invicta virus-1 or SINV-1. It is a natural agent and is a virus in the Dicistroviridae family, which is related to the well-known picorna-like viruses. It is a natural agent that appears and spreads naturally in the environment. The virus has been put through extensive analyses to ensure that it only infects the target species. The goal here is to use natural organisms to reduce RIFA numbers without using pesticides. During SINV-1 trials, they found when exposed, 23% RIFA nest were infected. All castes and stages of development are affected. Infected broods died within three months during laboratory studies, but effects of the virus in the field still needs to be evaluated. Surprisingly enough however, they found at the end of the study, there was a significantly higher survival rate in ants treated with the virus than those not treated with the virus (read full report: Tuft et al, 2014). So, back to the drawing board.

The second virus is Solenopsis invicta virus-3 or SINV-3. Like SINV-1, it is also a natural agent and only targets RIFA. Neither of these viruses have been introduced into the environment because they already exist naturally at low levels. The difference here is that when tested, this virus was found to cause a sevenfold decrease in the number of nests and nest size over the course of evaluation once exposed to the virus. Additionally, the virus appears to persist and spread naturally in the environment once it is introduced because it is already present in small quantities (read full report: Valles et al, 2022). Researcher’s emphasize that there is still a lot of work to be done and the virus is not a cure all. Currently, it will need to be used in conjunction with parasitic flies, microsporidia, or pesticides to see notable effects in RIFA populations, but it the first step in the right direction.

RIFA S. invicta Lateral view
Solenopsis invicta, Lateral view. Credit: April Noble, Antweb.org, Bugwood.org

RIFA Texas Quarantine Map- from the texas department of agriculture
RIFA Texas Quarantine Map. Credit: The Texas Department of Agriculture.

The graphic abstract from Valles et al., 2022.

Lionfish Leather. The Next Big Thing

Lionfish (Pterois volitaans) have been an ever-growing problem in the Atlantic Ocean since their introduction in the 1980s. People have tried everything under the sun, or sea, to control the population. Researchers and scientists have developed a robot that sucks up lionfish (see here), developed a unique clam-like traps to catch them (see here), and held festivals where people were crowned king and queen because they caught the most lionfish during the festival contest. People spear fish as a recreational sport and enjoy eating this ocean dweller as a delicacy. With all that, you would think we would have exhausted all the ways we could use this troublesome fish. You would be wrong.

Two individuals founded a company, called Inversa, that is turning lionfish into leather. They buy the lionfish from fishermen/women and process the fish hid by tanning them with drying agents and dye them before selling the leather to partner companies who fashion them into high-end products like wallets, belts, and handbags. The fish skin is said to be thinner that traditional leather, but stronger because the fiber structure runs crossways.

It is estimated that each hide can save approximately 70,000 native reef fish and that the hides are more sustainable than traditional animal leather, since traditional animal leather comes from grazers which require pastureland and release carbon emission. Not only does this company want to turn lionfish into leather, but they also want to buy lionfish from low income areas that currently do not have a market for lionfish, creating a “catch-to-cash guarantee”. This would offer a premium incentives and prompt payment for lionfish in low-income Caribbean areas where lionfish are destroying coral reefs, thus helping the local people and the environment.

lionfish leather. inversa copy
Lionfish leather. Credit: Inversa

Dallas City Council Discusses EAB

The Dallas City Council met this month to discuss the emerald ash borer (EAB, Agrilus planipennis) problem, now that that population has been confirmed to be in Dallas County. The city’s Urban Forest Task Force outlined an action plan to launch a sustainable solution for an environmentally disastrous problem. This included the continued implementation of a quarantine area, monitored movement of untreated wood, and ongoing EAB trap monitoring. Additional preventative measure will also be implemented, including examination and assessments of ash tree conditions throughout the city, and the removal of any trees that appear infected. Also, ash trees more than 24 inches in diameter and in good condition, or a grove of ash trees in good condition, will be given treatment to prevent infection. The estimated cost would be $470,000 through 2023.

During this presentation, the destructive nature of these invasive beetles was explained and the damage an infestation can cause was emphasized- estimating that many trees would likely die within two or three years after becoming infected. The action plan highlights the importance of continued outreach and education efforts since help from the public will be needed if we hope to stay ahead of this problem. Click here to read the full presentation.

  City of Dallas - Vertical - Full Color copy

Austin Fights Back Against Invasive Mussels

The Austin City Council approved a construction contract to build Copper Ion Generator systems at Austin’s three water treatment plants. The new systems will use electricity and copper electrodes to release copper ions into raw water pipelines. The addition of copper ions to raw water at the beginning of the process will deter invasive zebra mussels (Dreissena polymorpha) from settling on or entering pipes, which affects the water treatment plant infrastructure. The treatment process will then remove the copper ions before the drinking water is sent to costumers and consumers. The newly constructed system will replace the Copper Sulfate feed systems that are in place now and will eliminate the need to deliver, handle, and store large quantities of copper sulfate chemicals on site, as was previously necessary. Pipelines clogged with zebra mussels require more power to pump water through, and their presence can often affect the taste and odor of the water. This system will provide a more sustainable, long-term approach that will improve the water quality and the efficiency of the plant production. Read the full release.

 Zebra Mussel Progression (1) copy 2 
Zebra Mussel Progression. Credit: autstintexas.gov

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 20, 1pm- “Jumping Worms:” What We Know Now. REGISTER.
  • August 17, 1pm- How to get your project funded. REGISTER.
  • September 20, 1pm- Utilizing fire and grazing to manage invasive perennial grasses. REGISTER.
  • October 19, 1pm- Invasive plant management on non-industrial forest lands in the panhandle, FL after hurricane Michael. REGISTER


The Drunken Crab

A local distillery in New Hampshire, called Tamworth, has released a new whiskey that is flavored with invasive green crabs. The European green crab (Carcinas maenas) has been ecologically and economically devastating to the New England coast for decades. The crabs damage native shellfisheries, destroy coastal seagrass beds, and disturb the native ecosystem. There is currently no strategy in place to control the populations, which continue to grow, and there is no real commercial market or fishery for them. They are edible, but they are small and do not yield much meat. The most common use for the crabs is as bait. Now they have a whole new use… as a whiskey flavor base.

The whiskey, called Crab Trapper, is made with a bourbon that’s aged for about four years, and then steeped with a custom crab stock, corn, and spice blend. The crab is lightly present with coriander and bay spice. The body carries hints of maple and vanilla oak, and the spirit carries warm notes of clove, cinnamon, and allspice. The whiskey taste is described as a “briny and better than Fireball.” The distilleries founder and team see the whiskey as a unique means of addressing the ongoing crab problem.

Crab Trapper whiskey. Tamworth Distilling. bevvy.co
Crab Trapper whiskey. Credit: Tamworth Distilling, bevvy.co

Invasive Spotlight:

Giant Hogweed
(Heraclerum mantegazzianum)

Giant hogweed (Heraclerum mantegazzianum) is an aggressive competitor that is classified as a Federal Noxious Weed. Because of its size and rapid growth, it out-competes native plant species, reducing the amount of suitable habitat available for native wildlife. It prefers moist, disturbed soils, but can be found in a variety of habitats. Giant hogweed dies back during the winter months, leaving bare ground that can lead to an increase in soil erosion.

Giant hogweed is a biennial or perennial herb in the carrot family Apiaceae. It can grow up to 15 to 20 feet in height, with stout dark reddish-purple stems and spotted leaf stalks. Hollow stalks and stems produce sturdy bristles. Hogweed sports compound leaves with three leaflets that expand up to five feet. It resembles cow parsnip (Heracleum maximum) (which can also cause rashes), but its leaves are more dissected and pointier compared to those of cow parsnip. However, neither of these examples are found in Texas at this time. It is important this remains the case. To do this, we must all stay vigilant and any possible giant hogweed populations must be reported and removed immediately.

WARNING! Do Not Touch! Giant hogweed contains a substance within its sap that makes the skin sensitive to ultraviolet light. This can result in severe burns to the affected areas, producing swelling and severe, painful blistering. Large, watery blisters usually appear 15 to 20 hours after contact with the sap and sunlight. Contact between the skin and the sap occurs either through brushing against the bristles on the stem (as with a stinging nettle) or breaking the stem/leaves. In the event of contact, skin should be covered to reduce exposure to sunlight and washed IMMEDIATELY and thoroughly with soap and water. If you plan to eradicate it, be sure to wear gloves, long pants and a long-sleeved shirt.

To learn more about giant hogweed and management options visit the TexasInvasives info page. If you believe you have found a patch of giant hogweed, please REPORT IT! to the Sentinel Pest Network.

giant hogweed. Terry English. USDA APHIS PPQ
Giant hogweed (Heracleum mantegazzianum). Credit: Terry English, USDA APHIS PPQ, bugwood.org

 Hogweed leaves. Donna R. Ellis, University of Connecticut 
Hogweed leaves. Credit: Donna R. Ellis. University of Connecticut, bugwood.org

burns caused by exposure to plant. USDA APHIS PPQ. Oxford. North Carolina. USDA APHIS PPQ
Burns caused by exposure to hogweed plant. Credit: USDA APHIS PPQ, Oxford, North Carolina, USDA APHIS PPQ, bugwood.org


Get Involved Today!!

The Texas Invasive Species Institute (TISI) and The Texas Research Institute for Environmental Studies (TRIES) has 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 scientist, we could cover a much wider area, and gather a more substantial amounts 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.

Citrus Greening Workshops

We need your help to safeguard Texas Citrus, and it can start in your backyard!

TISI is offering educational workshops focused on the Asian citrus psyllid and the pathogen Citrus Greening. The Asian citrus psyllid and the Citrus Greening pathogen is threatening citrus in multiple Texas counties, and we need your help to monitor the spread. The workshop will highlight what you need to look out for, address USDA-APHIS Citrus Quarantines, and offer diagnostic services if you suspect your backyard citrus has either the psyllid pest or Citrus Greening pathogen. This includes providing trapping materials, assisting with management strategies, and more.

Please contact invasives@shsu.edu so we can schedule a workshop (virtual or in-person) for you or your group this year!

Aquarium Watch: Looking for Prohibited Invasive Aquatic Species

Please help texasinvasives.org and natural habitats by looking for 14 prohibited invasive aquatic species being sold in your local aquarium store. With just one photo you can assist us in finding and documenting which stores are selling prohibited species. Texasinvasives.org will contact the appropriate Texas institutions to remove the species for sale.

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.

Citrus greening. JM Bove
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.

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.

More News

City Continues Battle Against Toxic Algae, Zebra Mussels
Waterways in the Austin area continue to be monitored for harmful neurotoxins produced by stagnant algae proliferating, which can affect the safety of city, and invasive zebra mussels, which present a problem, disrupting the ecosystem that is already under stress. austinmonitor.com

Different Invasive Species Require Different Approaches
Understanding the different scales of the issues we face is an important first step. Problems of different scales require different solutions, and each problem requires a different tool. post-journal.com

After Manistee River Infestation, Scientists Try to Unravel the Mystery Of ‘Rock Snot’
Snotty-looking globs of invasive algae mats found in the Manistee River alarmed freshwater scientists and state environmental authorities who are now trying to figure out to what degree “rock snot” algae (Didymosphenia geminata) remain an ecological threat to Michigan rivers. mlive.com

Off-Season Cattle Grazing to Help Control Fire Danger from Invasive Cheatgrass
Cheatgrass (Bromus tectorum) is responsible for much of the increasing wildfire danger in the Intermountain West. Scientists have discovered that fire danger can be reduced through targeted cattle grazing during the dormant growing season. sciencedaily.com

Invasive Wasp Tests Nature's Strengths and Weaknesses
The Sirex woodwasp (Sirex noctilio) has caused major damage in the Southern Hemisphere and could spread throughout North America due to its ability to reproduce at rates 2-3-times higher in North America than in its native range in Europe. phys.org

Though Cute as Pets, Goldfish Are Highly Invasive Once in The Wild
Pets released into the wild can wreak havoc on native biodiversity. Goldfish (family Cyprinidae), for instance, make wonderful pets, but their voracious appetites, tolerance for cold waters, and bold behavior compared to other native species in the water make them a "triple threat”. smithsonianmag.com

More And More People Are Becoming Aware of The Dangers Posed by Invasive Hornets
Wasps and hornets have a remarkable capacity of surviving transportation and establishing invasive populations in new areas. Research shows that these invasions and the socio-economic impacts they cause do not go unnoticed. phys.org

Vocal Non-Native Songbird Could Change Britain's Dawn Chorus as We Know It
A new study warns the red-billed Leiothrix (Leiothrix lutea) is a tiny, loud, brightly colored songbird that could be emerging as a new invasive species in Britain, threatening to dominate the dawn chorus of native robins, blackbirds and warblers. sciencedaily.com

Albatross Populations Are Declining Due to Invasive Mouse Species
Researchers shed light on decades-long confusion surrounding the impact of invasive house mice (Mus musculus) on the critically endangered Tristan albatross (Diomedea dabbenena). phys.org

Why Confronting Invasive Species Is One of The Best Ways to Prepare for Climate Change
Ecological effect of invasive species is comparable to the combined effects of invasives plus warming temperatures, drought or nitrogen deposition. This suggests that preparation for climate change is to manage invasive species at the local level. phys.org


If you would like to highlight a successful invasive species project or nominate a special person to be highlighted in an upcoming iWire, please send the details to iwire@texasinvasives.org.


Citizen Scientists Spotlight
Hydrilla Be Gone

Conservationist gathered last month to begin work removing the last dense strands of hydrilla (Hydrilla verticillata) from the San Marcos River. Hydrilla is believed to have first been introduced to the river in the 1970s to be farmed for aquariums. Since then, it has been left to grow unchecked. Constant year-round water temperatures have provided the invasive aquatic plant with a perfect environment to grow unhindered, replacing local vegetation, lowering dissolved oxygen, and spreading quickly.

Individuals and volunteers with the Texas State University, City of San Marcos, the Meadows Center, and the Texas Conservation Alliance joined forces to remove the hydrilla. The effort to remove large patches of hydrilla is part of the Edwards Aquifer Habitat Conservation Plan. The goal is to remove invasive plants and fish from the area to eliminate any disturbances that may be harmful to the endangered species found in the San Marcos River and the nearby Comal River. This includes the fountain darters (Etheostoma fonticola), Texas wild rice (Zizania texana), and the San Marcos salamander (Eurycea nana). The conservation plan also ensures that the city cannot over pump from Edwards Aquifer.

In areas where hydrilla has already been removed, native regrowth can already be seen. Propagation of native species is happening on its own. Once the last, dense patch of hydrilla is removed, the team will go back for maintenance to assure regrowth does not occur. They hope that the bulk of the invasives will be removed from San Marcos River by 2023 and that “maintenance mode” will be complete by 2027.

  san marcos river clean up.spectrum news.charlott scott.jpg
San Marcos River Clean Up. Credit: Spectrum News, Charlott Scott.


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 Disease Workshop- Open to the public
Date: July 9th
Time: 10:00am - 11:30am
Place: Zoom
Register HERE
Please email Ashley Morgan-Olvera if you have any problems registering.