December 2015
Zebra Mussels Found in Dean Gilbert Lake

Dean Gilbert Lake, a small, 45-acre lake in Pecan Grove Park of the city of Sherman, unfortunately has become the eighth Texas lake to be infested with zebra mussels (Dreissena polymorpha). How the zebra mussels were introduced to the lake is not clear. The lake has no boat ramp, but it is used by kayakers, canoers, and small boaters. In addition, the Texas Parks and Wildlife Department reports that a leak was discovered in an underground pipeline that carries water from Lake Texoma beneath Dean Gilbert Lake; Lake Texoma was the first Texas lake to be infested with zebra mussels. The lake also drains into the Red River, which harbors zebra mussels.

To repair the pipeline leak, the lake will be at least partially drawn down. This may help to manage the zebra mussels. "We will be monitoring the zebra mussel population in the lake," said Brian Van Zee, TPWD Inland Fisheries regional director. "We are working with the NTMWD [North Texas Municipal Water District, owner of the pipeline] and the City of Sherman to explore possible treatment options."

TPWD reminds people using the lake to take the necessary precautions to ensure zebra mussels aren’t spread to other bodies of water. Remember to drain all water from bait buckets before leaving, put any caught fish on ice, and clean-drain-dry all watercraft and equipment.

For more information, see the TPWD's press release.

zebra mussel

Photographer: Amy Benson
Source: U.S. Geological Survey

zebra mussels


African Warthogs in South Texas

The Chaparral Wildlife Management Area in South Texas has become the first public wildlife area in which hunters have harvested African warthogs (Phacochoerus africanus). This is worrisome because warthogs have the potential to cause environmental and property damage similar to that caused by feral hogs that plague Texas and much of the Southern half of the U.S.

While related to the feral hogs, the warthog differs from its cousin in that it has a broader snout with four much larger tusks, can reach 200 plus pounds, burrows, and is diurnal. Originally imported for sport hunting, the warthogs harvested on Chaparral WMA property likely escaped from private land (landowners can legally own and import many exotic species such as warthogs). Because they burrow, warthogs can easily escape livestock areas and breach fencing. The Chaparral WMA animals represent what is believed to be a self-sustaining feral population, the only one on the continent. The climate of South Texas is similar to that of the warthog’s native sub-Saharan habitat. Sows can have litters of up to 8 piglets and can reproduce before they reach a year old.

Hunters have bagged warthogs in other counties in south Texas. The Texas Parks and Wildlife Department is encouraging hunters to kill any feral and free-ranging warthogs and feral pigs they come across, as they are not protected by Texas game laws. Read more about the warthog problem in this Houston Chronicle article.


Photo credit: African Wildlife Foundation,

Invasive Spotlight:
Cactus Moth
Cactoblastis cactorum)

The cactus moth, Cactoblastis cactorum, is a considerable threat to the native Opuntia cactus population and the ecosystem it supports. The larvae of the cactus moth live and feed communally inside the pads of any species of prickly pear cacti, which eventually kills the plant if the infestation is high enough. The cactus moth, a native of South America, is so efficient at eliminating Opuntia cacti that it is used as a biological control agent in areas where Opuntia are invasive.  It has the portential to destroy Opuntia communites from Texas down through Mexico.

Cactus moth larvae are pink-cream colored at first and as they age they become bright orange-red with large dark spots forming transverse bands. Mature larvae are 25 to 30 mm long. The larvae are much easier to discern than the non-descript adults, which are gray-brown moths with faint dark spots and wavy transverse lines marking the wings and long antennae and legs. The wingspan of the adults ranges from 22 to 35 mm. Females lay on average 70-90 eggs in a distinctive stick-like formation that extends out from the cactus pad.

Damage to cactus pads by feeding can be identified by characteristic oozing of internal plant juices and insect droppings. The interior of the pads may be entirely eaten, resulting in a translucent pad.

The cactus moth has not been reported in Texas, but experts predict that its spread to Texas is not far off. It is established in Florida and South Carolina and has been reported in Alabama, Mississippi and Louisiana. Because of its potential for ecological and agricultural harm, stakeholders have formed an inter-agency partnership to monitor its distribution, the Cactus Moth Detection and Monitoring Network. It is also one of the “Dirty Dozen” pest species identified by the Texas Invasive Plant and Pest Council. Therefore, it is one of the “Report It!” alert species on the website and reporting app.

If you believe you have found a cactus moth, please report this species.

Follow this link for more information on the cactus moth.

Cactus moth adult, larva, & eggs

Photo credits: (top) Susan Ellis, USDA APHIS PPQ,; (mid) Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services,; (bottom) CMDMN

cactus moth damage

Left: Frass and oozing. ( ppri/Fact%20Sheets%20Library/Cactoblastis%20
cactorum, %20cactus%20moth.pdf)
Right: Translucence (LSU AgCenter)

Cactus Moth Map

Source: Cactus Moth Detection and Monitoring Network

6th Texas Invasive Plant and Pest Conference

The 6th Texas Invasive Plant and Pest Conference has been scheduled for March 9-11, 2016, at Sam Houston State University in Huntsville, TX. Plans are still being made, and registration is not yet open. However, here are the details that have been worked out so far:

  • Deadline for abstracts: January 21, 2016
  • Early-bird registration: ends by February 24. $50 for students and $150 for non-students
  • Student travel grants: application due by February 5, 2016

As more details become available, they will be posted on the website and here in the iWire.


TIPPC_Conference2016_date 2

More News

Brown Anole Crowding Out Native Green Anole
Often referred to as a chameleon, the native green anole (Anolis carolinensis) can change its coloring to blend in with the Texas landscape. These native anoles are becoming harder to find in cities like Houston, Corpus Christi and San Antonio as non-native brown anoles (Anolis sagrei) spread out from the garden centers to which they were once confined. Hitching rides as eggs in potting soil, the speedy brown anole is pushing into the green native’s habitat. Learn more about the surprising impact the brown anole has on the native green anole at this Texas Monthly article.

Spotted Lanternfly Spotted in Pennsylvania
Authorities in Berks County, Pennsylvania have quarantined five townships after the spotted lanternfly (Lycorma delicatula) was detected. Originally from Northern China, the spotted lanternfly has already caused damage in Korea and Japan. There are currently no known biological controls existing in the U.S. for the lanternfly, which has the potential to spread as over 40 plants are known to host it. Read about how to identify the spotted lanternfly and host plants at ScienceDaily.

Army Corps of Engineers Tries Novel Approach to Control Invasive Species
The Army Corps of Engineers has begun work on a $1.4 million project aimed at restoring native plant communities of Unity Island, of the City of Buffalo, NY. After removing invasive plants along the island's Lake Erie waterfront, the Corps will use an innovative water circulation system together with invigorated wetlands to try to control invasive plant species growth, restore the native shoreline, improve hydrology, and improve wildlife habitat. Learn more about the restoration project at the the Buffalo News.

Wyoming Waters Clear of Invasive Mussel
Wyoming waters are still clear of zebra (Dreissena bugensis) and quagga (Dreissena polymorpha) mussels. The state legislature set up the Aquatic Invasive Species program to prevent the mussels and other invasive species from entering the state’s waterways. Utilizing boat inspections as their first line of defense, inspectors checked 45,967 boats this past year. Decontamination of three boats containing either mussel species were conducted. Close to 4,000 boats had previously been in contaminated waters. Annual water sampling is conducted to monitor for many invasive species. Read more about Wyoming’s success and the Aquatic Invasive Species program at

A Hard Look at the State of Invasive Species in the United States
The Government Accountability Office (GAO) is a branch of Congress that tracks and assesses federal performance. The GAO has recently reported to Congress that federal agencies have used roughly $260 million dollars a year to combat invasive species in the U.S., although it is not clear exactly how much each agency is using to address the invasive species problem. Major entrance pathways for invasives are identified in the report, with the most problematic lying in the realm of human behavior such as purposefully introducing new sport fish. The GAO has likened the U.S.’s invasive species problem to “a never ending oil spill”. Learn more about the GAO’s findings here.

Beavers in Patagonia
Beavers (Castor canadensis) were introduced to the forests of Tierrra del Fuego in the mid 1940’s and have since spread to Patagonia, where they are negatively impacting biodiversity. A graduate student from Duke spent three years studying their behavior in order to better understand biological invasions and development better management tactics. Read more about beaver behavior and how insight into invasion management was obtained at

Deep Water Dive Reveals Invasive Species
A rare look at the deep ocean communities associated with maerl, a coralline red algae and associated organisms, off the coast of the Island of Rhodes in the Eastern Mediterranean Sea, has given scientists new insight into the range of some of the area’s worst invasive species. Known to impact shallow depth communities, a number of alien invasive species -- including fireworms, the red seaweed Womersleyella and three Caulerpa species -- were found in this deep, low-light and low-temperature environment. How these alien species affect the maerl communities is not fully understood. Learn more about the dive at

If you would like your invasive species event or news listed in the next 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 of early detection of 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:


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