May 2018
Be On the Lookout for the Cuban Tree Frog in Southern Texas

TheCuban tree frog, Osteopilus septentrionalis, a native to Cuba, the Bahamas, and the Cayman Islands, is an invasive in the Caribbean and Florida. The frogs, which can eat smaller frogs and grow as large as an adult's fist, "… have noxious skin secretions, and they can clog plumbing and cause power outages by short-circuiting utility switches where they seek refuge," says USGS biologist Brad Glorioso.

Despite repeated occurrences in several states over many years, it was not believed that Cuban tree frogs had successfully established outside of Florida in the mainland United States. That has changed: in 2017, large numbers were found in New Orleans and the first record of a Cuban tree frog in Texas was reported in The Woodlands.

Now that a Cuban tree frog has been found in Texas, it is important that residents in Southern Texas, especially along the coast, be on the look out. These areas "would be the first places they may become established where the climate is mild. These animals are originally from the Caribbean area, so they like it warm," Glorioso said. According to a USGS report, once they become established, it will be unlikely that the frogs can be eradicated.

USGS provides a fact sheet that describes the Cuban tree frog. Adults are the largest tree frogs in the U.S., growing up to 6.5 in. Its coloration is highly variable, but it may be distinguished from native tree frogs by the fact that its toepads are noticeably large -- similar in size to its eardrum, its skin is bumpy like a toad's, the dorsal skin on adults is fused to the skull, and the single vocal sac of calling males inflates bilaterally, giving the appearance of two sacs. Its call, which is a "rasping snarl or rubbery snore", may be confused with that of the southern leopard frog (Lithobates [=Rana] sphenocephalus.

If you think you have found a Cuban tree frog, please collect it if possible and report it to the USGS (take up to 4 photos to submit) and to (put "Cuban tree frog" in the subject line). Information on how to collect a Cuban Tree frog can be found here. Let's keep it out of Texas.

cuban tree frog
Credit: Denise Gregoire, U.S. Geological Survey

green cuban tree frog
Example of color variation. Credit: Leanna Powers

treefrog toepads MEM
Comparison of toe pads of native and Cuban tree frogs. Credit: Monica McGarrity, TPWD

PlantRight Unveils PRE, Its Online Plant Risk Evaluator for Non-native Ornamental Plants

The iWire wrote about PlantRight in the January 2017 issue. PlantRight is an organization that is working to remove invasive plants from the nursery trade. "Recognizing that prevention is the most effective way to combat their spread, PlantRight offers an opportunity for the nursery industry to take the lead on this issue." As a very important step in that direction, PlantRight partnered with several experts from organizations around the country (including the editor of the Wire) to develop an online tool for evaluating non-native, terrestrial ornamental plants for their invasive tendencies. Called PRE for "plant risk evaluator", the tool allows anyone to search for a particular species and obtain a score that indicates the species' potential for invasibility. This month, PlantRight unveiled PRE.

"The project involved evaluating 50 economically-important landscape plants in each state, for a total of 200 evaluations, with special focus on the more contentious yet popular plants... The project also involved recruiting regional plant experts to participate as volunteer reviewers of these evaluations." One benefit of the tool is that it takes into account the fact that a species may be invasive in some parts of the country but not in others.

For more detailed information on PRE, click here. You'll also find links to interviews with the PRE screeners at Atlanta Botanical Garden, Botanical Research Institute of Texas, Chicago Botanic Garden, and the University of Minnesota Landscape Arboretum. Funding for the project was provided by the Horticultural Research Institute and the USDA Farm Bill. An overview of this Farm Bill project with links to all 200 plant risk assessments is here.

PlantRight logo


7th TIPPC Conference: Deadline for Symposium Proposals Extended

The 7th Texas Invasive Plant and Pest is taking place October 23 - 26 in Austin (venue to be determined). Plans for the Conference are still being finalized, but you may now submit abstracts and proposals for symposia, and students may apply for a Student Travel Grant on the Conference website. The deadline for submitting symposium proposals has been moved to Friday, June 29, the same deadline for submitting abstracts and applications for Student Travel Grants. Please consider organizing a symposium that brings together several speakers on a single topic, allowing the exchange of information, ideas and expertise.

Check back at that website and our Facebook page for more information as it becomes available. Information will also be updated here in the iWire.


TIPPC Conference 2018 date


Texas A&M AgriLife Extension Publishes KR Bluestem Management Guidelines

It is well known among managers of conservation lands, ranchlands, roadsides, and others landscapes that the control of King Ranch bluestem (Bothriochloa ischaemum) and other old world bluestems is very difficult. Given this situation, it would be nice if there were a source of up-to-date information to turn to that could provide management guidance. Fortunately, that source now exists. Texas A&M AgriLife Extension recently published a guide called “Introduced Bluestem Grasses: Management on Native Lands”. It covers the identification of different species of introduced bluestem, including KR bluestem and Kleberg bluestem (Dichanthium annulatum), as well as management strategies. It recognizes the difficulty and complexity in controlling the bluestems, and that different conditions will require different strategies. Their guide can be found here (pdf). Thank you, Texas A&M AgriLife!

Credit: Karan A. Rawlins, University of Georgia,

Tyler Earns Arbor Day Foundation Award in Part for Invasives Work

For its third consecutive year, Tyler has received the Arbor Day Foundation’s Tree City USA Growth Award for 2017. The Growth Award highlights innovative programs and projects as well as increased commitment of resources for urban forestry. This year’s Growth Award was achieved due to the urban forestry partnership with the City of Tyler and the University of Texas at Tyler and the invasive species campaign that was started on Rose Rudman Trail in conjunction with public education and awareness classes regarding urban forest health issues. Congratulations and thank you for your work!

  Tyler receives Arbor Day Foundation award
Credit: East Texas Review

Explosion in Zebra Mussel Population Worries Lake Travis Divers

A group of divers who spend their weekends on Lake Travis is trying to raise public awareness about a dramatic increase in invasive zebra mussels (Dreissena polymorpha) they've seen in the lake over the past year.

The unwanted mollusks were first confirmed to be in Lake Travis in July 2017. But Matt Jacobs, a dive instructor with Dive World Austin, is deeply concerned with the rate at which they've spread around the lake in such a short time. "Six or eight months ago, it was very rare to see, you'd pick up an object and maybe there would be one or two," Jacobs said. "But now there are entire areas that are just covered with zebra mussels and they are spawning and spreading unbelievably quickly."

Among the many problems the mussels cause, they also make lake floors or rocks too sharp to walk on. As a result, swimmers and waders will need to beware the mussels, and divers will likely have to wear more covering. Jacobs said he'll need to have two sets of diving equipment, one for use in zebra mussel-infested waters and one for use in places free of the mollusks.

The mussels likely traveled to Lake Travis as hitchhikers on watercraft or equipment. Boaters are legally required to drain all of the water from their boat and anything on board before leaving or heading to another freshwater body. Then they have to clean and dry their boats, as well as gear, including even swimsuits, paddles, wetsuits, PFDs, and water shoes. The rules apply to all types of boats — from motorboats to kayaks — and a first violation can lead to a fine of up to $500.

For more information, see the article and video at KXAN. The video clearly shows the extent of the infestation.

Credit: Amy Benson, U.S. Geological Survey

Invasive Spotlight:
Yellow Floating Heart
(Nymphoides peltata)

Yellow floating heart is a freshwater floating perennial that threatens aquatic habitat, especially in East Texas. It grows rapidly, covering the entire surface of the water and shading out and outcompeting native vegetation. Decomposing vegetation impacts water quality and shading can cause severe declines in algae, disrupting the entire food web.

Yellow floating heart possesses runners that aggressively root in the substrate. Most of the leaves of yellow floating heart are floating and range from 1.2 – 5.9 in in diameter (3 – 15 cm), have slightly wavy margins, usually grow in an opposite and unequal arrangement, are typically somewhat heart shaped, and are often purplish underneath. Flowers are yellow with five petals, each of which has fringed edges, and range in size from 1 – 1.5 inches (3 – 4 cm) in diameter. From 2 to 5 flowers are held above the water surface on a stalk.

Yellow floating heart was intentionally introduced in the U.S. as an ornamental plant in water gardens and escaped captivity. It has since spread to numerous states from coast to coast. Watercraft spread it by fragmenting it and by carrying it to new locations. It also spreads by producing daughter plants that break off and float to new areas, via rhizomes and tubers, and by seeds, which are spread by water currents and animals. Although this species is prohibited in some states, including Texas, it is widely available online. As a TPWD regulated species, it is illegal to sell, buy or transport yellow floating heart in Texas.

Because of its potential negative impacts in Texas, yellow floating heart is a Report It! species as part of the Sentinel Pest Network, a component of If you believe you have found yellow floating heart, please report this species.

Learn more about yellow floating heart at
yellow floating heart
Credit: Lyn Gettys Source: University of Florida

yellow floating heart flowers
Credit: Mark Malchoff, Univ. of Connecticut

yellow floating heart leaves
Credit: Vick Ramey, Univ. of Florida

More News

Russian Cuckoo Invasion Spells Trouble for Alaskan Birds
Common cuckoos (Cuculus canorus) and oriental cuckoos (C. opatus) in eastern Russia appear to be expanding their breeding range into western Alaska, where songbirds are naive to the cuckoos' brood parasitism, researchers report. The native birds could therefore suffer significant losses if cuckoos become established in Alaska. For more information, read the article at

Novel Ecosystems Provide Use for Some Native Birds
Ecosystems that have been altered by human activities can provide suitable habitat for native birds, according to scientists in the United States and Australia. For more information, read the article at

Introduced Bullfrogs Cause Deadly Fungus Outbreaks in Western US
A new study draws a link between the introduction of American bullfrogs (Rana catesbeiana) to the western half of the United States and the spread of the fungus Batrachochytrium dendrobatidis (Bd) that is deadly to amphibians and is only found in the Western U.S. For more information, read the article at

Researchers Use Lidar to Locate Invasive Fish and Preserve a National Treasure
An aircraft-mounted instrument could offer a faster way to locate and capture the non-native fish at Yellowstone National Park during the brief weeks each year when they come into shallow water to spawn. Learn more at

Long-Term Study Reveals One Invasive Insect Can Change a Forest Bird Community
Eastern hemlock (Tsuga canadensis) forests have been declining due to a non-native insect pest. A new study indicates that a single insect species has led to a less diverse bird community. Read more at

If Pigs Could Fly: How Can Forests Regenerate Without Birds?
For Guam, removing invasive pigs (Sus scrofa) from limestone forests may have a detrimental effect on the regeneration of the plant communities of those forests. For more information, read the article at

Australia's $45 BILLION Pest Problem: Red Fire Ants
Texas and other southern US states aren't the only places where the red imported fire ant (Solenopsis invicta) is causing problems. Austrialia is now home to the ants, with the potential to destroy crops, agriculture and wildlife with $45bn in damage. Read more in the Daily Mail.


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

Sentinel Pest Network and Invaders of Texas Species Workshops

Invaders of Texas workshops train volunteers to become citizen scientists to detect and report invasive species. Workshops, which are free, include information on the Sentinel Pest Network, which serves to increase the awareness and early detection of the Emerald Ash Borer, Cactus Moth, Asian Longhorned Beetle, and other pests of regulatory significance.

Workshops are tailored to meet the interests of your volunteer group, and supplementary session examples include an introduction to the TX Invaders mobile application and the Eradicator Calculator, a feature on designed to help organize and track volunteer-based eradication efforts.

Upcoming Workshops:

Saturday, June 16, 2018
Location: Derrell Hall Educational Building, 2505 N. Center Street (Bonham, TX)
Contact: Christine Miller

Friday, October 12, 2018
Location: Mission Branch Library, 3134 Roosevelt Avenue (San Antonio, TX)
Contact: Rachel Cywinski

Sentinel Pest Network Workshop
Wednesday, October 17, 2018

Location: Mission Branch Library, 3134 Roosevelt Avenue (San Antonio, TX)
Contact: Rachel Cywinski

Sentinel Pest Network Workshop
Sunday, October 21, 2018

Location: Mission Branch Library, 3134 Roosevelt Avenue (San Antonio, TX)
Contact: Rachel Cywinski

For more information or to register to attend a free workshop, please visit the Workshop Page.