September 2019
Innovative Fish Adoption Program Protects San Marcos River from Invasive Species

The San Marcos Parks and Recreation Department (SMPRD) has devised an innovative way to protect both the San Marcos River and the fish that aquarium owners don't want any more. Unfortunately for the river, aquarium owners who no longer want their fish sometimes release them into the river, potentially adding to the ecological harm being done by invasive species. There are several options to releasing pet aquatic organisms into natural waters. SMPRD has developed a way to make it easier for people to use one of those strategies: finding others to adopt their fish.

San Marcos’ Pet Fish Drop Off program started in 2017 to reduce the number of non-native fish being dumped into the San Marcos River from aquaria and, most importantly, to educate the public about the impacts of non-native fish on native populations. The suckermouth catfish or pleco, Hypostomus plecostomus, is the fish they would most like to prevent from being released because of its important negative impacts on the river ecosystem (see the Invasive Species Spotlight below). They have also accepted "goldfish, angelfish, neons, beta, zebra, bala, gourami, cichlid, rainbow, Oscar, aquatic frog, carp, tetra and platy".

All of the fish are available for adoption. Interested individuals can simply stop by the Discovery Center, Monday to Friday 8 a.m. – 5 p.m., with their own take-home container. The Discovery Center is located at 430 Riverside Drive, San Marcos, TX. The phone number is 512-393-8327.

For more information, see this article at

Downlaod TPWD's Responsible Ways to Get Rid of Unwanted Aquarium Life - PDF, 123 KB.

don't dump your tank

San Marcos fish drop off
Credit: San Marcos Parks and Recreation Department

Ash Tree Species Likely Will Survive Emerald Ash Borer Beetles, But Just Barely

'Lingering ash.' That's what the US Forest Service calls the relatively few green and white ash trees that survive the emerald ash borer (Agrilus planipennis) onslaught. Those trees do not survive by accident, and that may save the species, according to researchers, who conducted a six-year study of ash decline and mortality.

The study is unique because it took place at a plantation of ash trees planted on Penn State's University Park campus in the mid-1970s.

"We found that genetic variation exists in trees from around the country, and through time -- especially as the emerald ash borer population collapses because host trees are rapidly disappearing -- the resistance that we observed will likely ensure the survival of the species," said Kim Steiner, professor of forest biology, College of Agricultural Sciences.

"We began measuring the decline in 2012, shortly after emerald ash borers arrived in the plantation, and we measured it every year through 2017," said Steiner. Although nearly all trees in the plantation were killed, genetics slowed the rate at which emerald ash borers injured and killed trees.

"This suggests that some ash genotypes, especially on favorable sites, will survive with lower densities of emerald ash borer beetles on the landscape," said Lake Graboski, Steiner's assistant.

Learn more at

Credit: Howard Russell, Michigan State University,

Ash orchard dying trees -Penn State
Dead trees in the Penn State orchard. Credit: Kim Steiner, Penn State University

Colorado Plans to Abandon Its Battle Against the Emerald Ash Borer

Emerald ash borer (Agrilus planipennis) was first discovered in Colorado in 2013, in the City of Boulder. A quarantine was placed on Boulder County, which prohibits the movement of all untreated ash wood and all hardwood firewood out of the quarantined area. The quarantine includes logs and green lumber, nursery stock, wood chips and mulch. Now the borer has been found outside of the quarantine area, leading Colorado forestry officials to propose to abandon the quarantine altogether. For more information, see this article in the Daily Inter Lake.

emerald ash borer
Credit: David Cappaert, Michigan State University,

Feral Hogs Encroaching on Montana-Canada Border

According to an article in the Daily Inter Lake, environmentally damaging feral hogs are potentially moving into the United States from Canada.

"Large populations of feral hogs throughout Saskatchewan and Alberta have been slowly encroaching on the Montana-Canada border, placing wildlife experts, farmers and other stakeholders on edge.

"Multiple reports have emerged of groups of feral hogs being spotted “very close” to the border. One of the most recent sightings occurred earlier this summer when eight mature pigs were discovered in Canada directly above Lincoln County. That’s according to John Steuber, the state director and a supervisory wildlife biologist for Wildlife Services, a program with the U.S. Department of Agriculture.

“They can decimate the range land by tearing up everything,” said Tahnee Szymanski, an assistant veterinarian with the Montana Department of Livestock. While extensive damage to lands is a major potential problem, Szymanski said the diseases the pigs have been known to carry are of equal concern. She points to two primary diseases that could have sizable impacts on domestic livestock and other animals in the wilderness: African swine fever and foot-and-mouth disease."

feral hog
Credit: Texas Parks and Wildlife Department

Meeting: Innovations in Invasive Species Management

Consider attending the third annual Innovations in Invasive Species Management Conference Training to be held in Coeur d’Alene, Idaho December 10 - 12, 2019 at the Coeur d’Alene Resort. The conference hosts people from throughout the US and World looking for new techniques and inspiration from successes to manage a wide range of invasive species. Be ready for some exciting new topics and demonstrations in 2019.

For more information and to register, go the conference website.


pnwipc logo

Meeting: Texas Gulf Region Cooperative Weed Management Area Workday and Semiannual Meeting

The Texas Gulf Region Cooperative Weed Management Area (TGR-CWMA) will be hold its biannual meeting and workday on October 23, 2019. The workday to remove Brazilian peppertrees will begin at 8:00 am and end at 11:30 am. Meet at the Leonabelle Turnbull Birding Center on Ross Avenue. Please dress appropriately and bring water. Tools and gloves provided, but bring your own gloves if you have them.

The CWMA's semiannual meeting will be held at 2pm, at the City of Port Aransas Nature Preserve Headquarters, 106 Cut Off Rd., Port Aransas, TX 78373. The meeting is open to the public and you are encouraged to attend. Come and meet us, and hear what the CWMA has accomplished and what we are planning.

See you there!

remove Brazilian peppertree

Credit: Hans Landel, Lady Bird johnson Wildflower Center


Webinar: Information on Recently-Discovered Spotted Lanternfly

This webinar covers the biology, identification and management of the spotted lanternfly in the southeastern U.S.

The spotted lanternfly (Lycorma delicatula) is an invasive planthopper native to China, India and Vietnam. It was first discovered in Pennsylvania and has spread to other counties in the eastern United States. This insect has the potential to greatly impact agricultural crops such as grapes, hops, and hardwoods. This webinar instructs homeowners on what they can do to help slow the spread of this invasive pest, and how to report sightings of spotted lanternfly outside of the quarantine. For more information and to view the webinar, go here.

spotted lanterfly
Credit: Lawrence Barringer, Pennsylvania Department of Agriculture,

Invasive Spotlight:
Armored Catfish
(Hypostomus plecostomus)

Like other invasive species, the armored catfish can reduce the abundance of local indigenous species by out-competing them for resources or by feeding on them. It is a hearty fish that can withstand a wide range of ecological conditions. In fact, the fish can gulp air and survive out of water for more than 30 hours. Females can lay more than 300 eggs in their nests.

Also known as "plecos", the armored catfishes (Family: Loricariidae) are native to Central and South America. They are algivorous, mostly nocturnal, with a noticeable sucker located ventrally (on the lower surface) on the head. Loricariids can range in size from 3 inches to over three feet in adequate conditions. Their flattened ventral surface allows the fish to use their suckers on most substrates. The adipose fin has a spine and pectoral fins have thick, toothed spines.

Plecos are common in the aquarium trade. Unfortunately, the fish has been released into our Texas waterways by aquarium owners. Hypostomus plecostomus, perhaps the most ubiquitous species in North America, is now found in several Texas waterways.

Follow this link to learn more about the armored catfish.

Credit: US Geological Survey

More News

Study Shows Importance of Tailoring Treatments to Clearly Defined Weed Control Objectives
A new study shows that to work smarter, not harder, when managing invasive weeds, the first step is to clearly define your weed control objectives. The research compared different mowing treatments used to manage invasive musk thistle (Carduus nutans). Learn more at

Public Support for Gene Drives in Agriculture Tied to Limits
The first national survey inquiring about American attitudes toward agricultural gene drives shows more support for systems that are limited in scope and aimed at non-native insects. Learn more at

Look Out, Invasive Species: The Robots Are Coming
In the first experiments to gauge whether biomimetic robotic fish can induce fear-related changes in mosquitofish, researchers found that even brief exposure to a robotic replica of the mosquitofish's primary predator can provoke meaningful avoidance behaviors and physiological changes associated with the loss of energy reserves, potentially translating into lower rates of reproduction. Learn more at

Citizen Scientists Help Study How the Small Cabbage White Butterfly Spread Throughout the World
Through close examination of genetic variation and similarities between existing populations, and comparisons of historical data regarding infestations of the small cabbage white butterfly (Pieris rapae) in Brassicaceae crops, a consortium of researchers document how humans helped the butterfly spread from Europe across the world. Scientists from eight institutions partnered with more than 150 volunteer citizen scientists from 32 countries to detail the pest's range and current genetic diversity. Learn more at

Early Rice Farmers Unwittingly Selected for Weedy Imposters
Early rice growers unwittingly gave barnyard grass (Echinochloa crus-galli) a big hand, helping to give root to a rice imitator that is now considered one of the world's worst agricultural weeds. Learn more at

A Modelling Tool to Rapidly Predict Weed Spread Risk
A new statistical modelling tool will enable land management authorities to predict where invasive weed species are most likely to grow so they can potentially find and eliminate plants before they have time to spread widely. Learn more at


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:

Tuesday, October 8, 2019 (6 pm)
Sentinel Pest Network Workshop

Location: Martin Dies, Jr. State Park, 634 Park Road 48 S (Jasper, TX)
Contact: Lori Horne

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