July 2017
Workshop on Controlling Invasive River Cane Along the Medina River, Aug 7

Join us on Monday, August 7th, to learn about Arundo donax. This non-native, invasive plant—also referred to as river cane or giant reed—has taken over river banks across the Hill Country, including stretches of the Medina River. Classroom presentations and a site visit will highlight the harmful impacts of this plant and what we can do as a community to control it and restore our river banks.

The workshop is free and open to anyone, and we especially encourage those who own or manage creek-side property to attend. Free lunch provided by the Bandera County River Authority and Groundwater District.

Meet at 10:30 am at the Bandera County River Authority & Groundwater District Office (440 FM 3240 Bandera, TX 78003). Expect the to end at 2:00 pm.

Learn more.

Arundo with man
Credit: Forest and Kim Starr, Wikipedia.org

HCA Logo

Bandera County River Auth

Urban Feral Hogs Program Slated for Aug. 31 in San Antonio

A program on urban feral hogs (Sus scrofa) will be held 5-9 p.m. Aug. 31 at the Texas A&M AgriLife Extension Service office in Bexar County. The office is in suite 208 of the Conroy Square business complex, 3355 Cherry Ridge Dr., San Antonio. Cost is $15. Attendees are asked to RSVP by Aug. 25 to Denise Perez at the AgriLife Extension office, 210-631-0400.

"Each year, feral hogs cost the state millions of dollars in property damage,” said Sam Womble, AgriLife Extension agent for agriculture and natural resources, Bexar County. "They are also responsible for contributing to the contamination of water resources and can be purveyors of disease. While people usually think of them as a problem for rural areas, they also invade urban spaces."

The program will address several aspects of urban feral hogs as well as methods for their control. "Experts from AgriLife Extension, Texas Parks and Wildlife Department and the Texas Animal Health Commission will present at the program," Womble said.

Three hours of Texas Department of Agriculture continuing education units are available. Refreshments will be provided.

Learn more.

feral hog
Credit: Texas Department of Agriculture

feral hog damage
Credit: Billy Higginbotham, Texas AgriLife Extension Service, Bugwood.org

Perhaps We Needn't Worry About the Giant African Land Snail?

The giant African land snail (Lissachatina fulica) is considered one of the most invasive species in the world. It eats a variety of vegetation, including crop species. Introduced to Florida, it threatens to appear in Texas, and thus is one of the species on the Texasinvasives.org's Sentinel Pest Network list of species to be on the look out for.

However, research from Christmas Island suggests that the snail may in fact not be problematic. There, it was found to feed only on leaf litter, and not on seedlings as predicted or other living plants. It therefore doesn’t appear to be impacting the environment, at least by the measures of the study. While the study doesn't rule out other negative impacts, it does illustrate that research is needed to demonstrate whether a species is actually harmful. In the meantime, perhaps following the "precautionary principle", which states that we should err on the side of caution, is the best course of action. For more information, see the article at The Conversation.com.

lissachatina_fulica 2
Andrew Derksen, FDACS/DPI

Invasive Species Curriculum for High School Teachers Presented at Workshops

The new high school curriculum on invasive species that can be used in environmental science classes and was developed by Texasinvasives.org, was presented in two workshops in July in Austin and San Antonio. It is designed to introduce students to invasive species and train them as Invaders of Texas citizen scientists. It consists of four units with a total of eleven lessons covering basic information on invasive species, mapping and GPS, invasive plant identification, and training to collect data on invasive plants as Invaders of Texas citizen scientists, plus a summative assessment. The lessons satisfy the TEKS 11-12 grade Environmental Science Section 112.37 (Environmental/Systems). Particpants in the workshops felt the curriculum can be fairly easily adapted for middle school. After revisions based on reviews by teachers piloting the curriculum, the curriculum will be made available on Texasinvasives.org. If you would like to pilot the curriculum, please contact us at invaders@texasinvasives.org.

Invaders of Texas citizen science training at Jacksonville High School in 2015, provided by Mike Murphrey, TAMFS. Credit: Laura Cook

Invasive Prey Indirectly Increase Predation on Their Native Competitors

Research published in 2015 by Max C. N. Castorani (Marine Science Institute, University of California, Santa Barbara) and Kevin A. Hovel (Coastal and Marine Institute Laboratory and Department of Biology, San Diego State University) demonstrate that an invasive species that is preyed upon by native predators can have both direct and indirect negative impacts on native species. The researchers performed experiments in Southern California to study the interactions among the invasive Asian nest mussel (Arcuatula senhousia) and native bivalves and predators. They found that the nest mussel "reduces the diversity, abundance, and size of native bivalve recruits by preemptively exploiting space in surface sediments". In other words, when the nest mussel larvae settle out of the water and begin the final stage of their life on the bottom, they outcompete the native bivalves for space. In addition, the nest mussels attract more native predators, which increases predation on the native bivalves. This is am important result because it illustrates another, indirect mechanism by which an invasive species can impact native species. Learn more from the research article.

Credit: Anthony Fisher, exoticsguide.org

nest mussel impacts
Credit: Castorani & Hovel, Ecology 96:1911-1922. Solid lines = direct effects, dashed line = indirect effects.

Laurel Wilt Webinar

There will be a webinar on laurel wilt (Raffaelea lauricola) and the insect that spreads it, the redbay ambrosia beetle (Xyleborus glabratus), in August, 2017, sponsored by Texasinvasives.org and USDA-APHIS. Presenters from Texas A&M Forest Service will discuss the disease and the insect. More information on the date, time and registration for the webinar will be available on the Texasinvasives.org Facebook page.

red bay ambrosia beetle
Credit: Michael C. Thomas, Florida Department of Agriculture and Consumer Services, Bugwood.org

Invasive Spotlight:
Tawny Crazy Ant
(Nylanderia fulva)

The tawny crazy ant was first found in Houston (Harris County) in 2002 and has since spread to many counties in central and eastern Texas.

Tawny crazy ants could be suspected if you detect many uniformly sized, 1/8 inch long ants with reddish-brown coloration in your landscapes, including foraging indoors from outdoor nests. The ants form loose foraging trails and also forage rapidly and randomly, which earns them the title as "crazy".  The ant has a smooth and rather dull body surface, bears rows of stiff hairs on its thorax, has a covering of fine hairs on its sides, and possess relatively long legs and antennae. There is a small circle of hairs, called the acidopore, present at the tip of the abdomen, as opposed to the typical stinger found in most ants.

The ants form colonies under objects in the outdoor landscape, including rocks, timbers and debris piles, among other things. A good distinguishing nest trait compared to other ants is that they do not build centralized mounds and do not emerge from nests through central openings.

In infested areas, large numbers (millions) of crazy ants cause a great annoyance to residences and businesses. They also tend to accumulate in electrical equipment, causing short circuits. Once a colony forms, the ants are practically impossible to eradicate.

The ants threaten wildlife, such as birds, by covering the ground and trees and will cause wildlife to move out of the area. Very little is known about other impacts to wildlife in the United States. They do displace the red imported fire ant.

Because of its potential negative impacts in Texas, the tawny crazy ant is a Report It! species as part of the Sentinel Pest Network, a component of Texasinvasives.org. If you believe you have found tawny crazy ants, please report this species.

Follow this link for more information on the tawny crazy ant.

tawny crazy ant
Credit: Bastiaan Drees, Texas A&M University

tawny crazy ant labeled
Credit: Alex Wild, http://www.myrmecos.net/2012/06/

crazy ants swarming on hand
Credit: http://insectbio.rice.edu/2013/12/02/texas-vs-ants-who-will-win/

More News

Getting to the Roots of Sahara Mustard Invasion in the American Southwest
Old World Sahara mustard (Brassica tournefortii) is spreading rapidly through southwestern US deserts, smothering the native wildflowers that draw tourists to the region and disrupting the desert ecosystem. A new study is investigating when the invasion originated and what enabled Sahara mustard to adapt so successfully, to gain insight into how to stop it. [Sahara mustard has been found in Ellis, El Paso, and Hudspeth Counties in Texas. (EDDMapS)] Read more at sciencedaily.org.

Invasive Weevil Spreads North, Endangering California's Palms
An invasive beetle, the South American Palm Beetle (Rhynchophorus palmarum) that crossed from Mexico into southern San Diego County more than five years ago is continuing to head north, threatening widespread destruction of ornamental palm trees and date palms. [The SAPB has also been found in south Texas.] Learn more at phys.org.

Intensive Fishing Finds No More Asian Carp Beyond Barrier to Lake Michigan
A major scare occurred on June 22 when a live 8-pound, 28-inch-long silver carp was caught beyond the barriers just nine miles from Lake Michigan. This sparked two weeks of intensive fishing in and around the Chicago waterway. Happily, it failed to produce any proof that more Asian carp have made it past the electronic barriers. However, the capture of the silver carp does indicate that the barriers are not foolproof and that continued vigilance is needed. Read more at phys.org.

Shale Gas Development Spurring Spread of Invasive Plants in Pennsylvania Forests
Vast swaths of Pennsylvania forests were clear-cut circa 1900 and regrowth has largely been from local native plant communities, but a team of researchers has found that invasive, non-native plants are making significant inroads with unconventional natural gas development. Researchers show a direct correlation between the extent of non-native plant invasion and distinct aspects of shale gas development. Learn more at sciencedaily.org.

Invasive Plant Species Can Enhance Coastal Ecosystems
A new study finds that an invasive species of seaweed, Gracilaria vermiculophylla, provides vital ecosystem functions in North Carolina mudflats where native habitat has severely declined. "With the progressive decline of coastal habitats worldwide, our findings suggest it's better to have a non-native habitat than no habitat at all," said Aaron Ramus, one of the researchers. Learn more at sciencedaily.org.

Common Carp Indirectly Threaten Waterbirds in Spain
The presence of the common carp (Cyprinus carpio), a freshwater invasive species spread worldwide, is alarmingly reducing the populations of diving ducks and waterbirds in Spain, including an endangered and a vulnerable species. According to new research, the carp feed on aquatic vegetation, which "radically" changes the waterbird community in shallow lakes. Learn more from the original research article at sciencedirect.com.

Removal of Invasive Shrub Could Be an Easy Way to Help Reduce Malaria Transmission
Removing the flowers of an invasive shrub, Prosopis juliflora from mosquito-prone areas might be a simple way to help reduce malaria transmission, according to a new study. Removing the flowers from villages in Mali decreased the local mosquito vector population by nearly 60 percent. This suggests that removing the plants themselves would also decrease mosquito populations. Learn more at sciencedaily.org.

Native Leech Preys on Invasive Slug in Japan
Citizen science has revealed the spread of the invasive giant slug Limax maximus and its potential native predator in Japan, providing new insights into predator-prey dynamics between introduced prey and native predators. Learn more at phys.org.

Ancient Pollen Study Indicates An Invasive Plant May Actually Be Native
A study of ancient pollen from Losotho demonstrated that what was thought to be an invasive plant is more likely a native shrub that has taken advantage of habitat disturbed by grazing. The results indicate the shrub has been in the area for at least 4000 years, instead of 100 years as previously thought. Learn more at 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.

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 Texasinvasives.org designed to help organize and track volunteer-based eradication efforts.

Upcoming Workshops:

--- None scheduled.

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