June 2018
Cedar Park, Round Rock and Leander Battle Zebra Mussels in Lake Travis

The cities of Cedar Park, Leander and Round Rock are located miles from Lake Travis, yet they are being impacted by the zebra mussels (Dreissena polymorpha) that recently infested the lake. The invasive bivalve was discovered in Lake Travis just last year, and already it is causing concern. The cities obtain at least part of their water from the lake through the Brushy Creek Regional Utility Authority (BCRUA), which was founded in 2007. Now the three cities and BCRUA will fund a $1.35 million joint chemical treatment station located in Cedar Park’s water treatment plant along Lake Travis. The station will utilize sodium permanganate—a common chemical used for water treatment—that will prevent the attachment and growth of zebra mussels in the raw water intake structures. Because it is impossible to rid the lake of zebra mussels, the chemical treatment will be a recurring cost that will need to be passed on to the consumers. For more information, see this article from the Leander/Cedar Park issue of the Community Impact newspaper.

zebra mussels
Credit: Amy Benson, U.S. Geological Survey

USGS Creates Maps Illustrating How Hurricanes Have Spread Aquatic Non-Native Species

More than 1,270 non-native (or non-indigenous) aquatic species (NIS) have been reported in the United States. Some of these have no known negative impacts, but of course many are invasive, causing a wide range of problems. Unfortunately, but not surprisingly, these species have the potential to spread further when hurricanes produce floodwaters and storm surges. Freshwater species can even move along the coast as freshwater flooding from inland reaches the shore and temporarily displaces salt water. To gain insight into the potential spread of NIS caused by the 2017 hurricanes, the Unites States Geological Survey (USGS) has produced a series of maps for 226 of them.

"The U.S. Geological Survey's Flood and Storm Tracker maps are terrific tools we now have available to help determine the spread of aquatic invasive fish, wildlife and plants caused by major storms like the hurricanes we had last fall," said John Galvez, who leads the Peninsular Florida Fish and Wildlife Conservation Office for the U.S. Fish and Wildlife Service, which is a branch of USGS. "The county-by-county maps are helping us make better decisions about where to target surveys and identify ways to eliminate the invaders before they get a foothold in new areas."

“The U.S. Fish and Wildlife Service is using it to decide where to conduct field surveys at national wildlife refuges in Texas and Louisiana,” said biologist Pam Fuller, the leader of USGS’s Nonindigenous Aquatic Species Program.

For more information, go here.

USGS logo

USGS map potential invasives spread after hurricanes

7th TIPPC Conference: Deadlines 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 deadlines for submitting abstracts, symposium proposals, and applications for Student Travel Grants have been moved to Friday, July 27. Please submit as soon as possible!

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


Kudzu, the Kudzu Bug, Soybeans and Two Tiny Wasps

This is a story about the sometimes complex nature of invasive species control. Kudzu (Pueraria Montana) is a highly invasive vine that can over-top native plants and trees. Having a biological control agent would be great, and that's exactly what the kudzu bug (Megacopta cribraria) is. It was not intentionally released, but found its way to North America on its own, probably through international commerce, and has spread throughout the southeastern United States. This would be wonderful story were it not for the fact that the kudzu bug likes to eat other leguminous plants, including soybeans. As a soybean pest, the kudzu bug can cause up to 60% loss in yields.

As if the story were not complicated enough, enter a tiny wasp, Paratelenomus saccharalis, that appeared in 2013; like the kudzu bug, the wasp was not intentionally released. It parasitizes the kudzu bug, and has been controlling it in Georgia. “There’s no manipulation or manual placement,” said Michael Toews, a University of Georgia entomologist. “The wasps naturally find any place that is infested with kudzu bugs. We found this wasp in every field that we examined in south Georgia.”

You can read more about the wasp and the bug in this article at ipmsouth.com. What the article doesn't discuss is that while the wasp has been great for the soybean farmers, it has made it more difficult for land managers trying to control kudzu. After all, the wasp is not limiting itself to kudzu bugs on soybeans. Fewer kudzu bugs means less control of kudzu, after all.

And now, another wasp enemy of the kudzu bug, also from Asia and also one that made it here on its own, was recently discovered.

See also the scientific article "From Asian curiosity to eruptive American pest: Megacopta cribraria (Hemiptera: Plataspidae) and prospects for its biological control", by Ruberson et al. (2012).

kudzu infestation
Kudzu bug. Credit: Hans Landel, Lady Bird Johnson Wildflower Center

Megacopta_cribraria (kudzu bug)
Kudzu bug. Credit: Flickr user CharlesLam, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=2344964

Invasive Spotlight:
Crested Floating Heart
(Nymphoides cristata)

Last month we covered the yellow floating heart, (N. peltata). This month we cover its relative.

Crested floating heart is a freshwater floating perennial. It has stolons (runners) that aggressively root. Most of its leaves float, and are somewhat heart-shaped with purplish undersides. It produces a 5-petaled white flower on a stalk. When it's not flowering it can be identified by its clusters of tuberous propagules that dangle from the node where the stem connects to the leaf.

As with many floating aquatics, crested floating heart will grow rapidly, covering the surface and shading out other aquatic plants and algae, disrupting the entire food web. As it dies and decomposes it can negatively impact water quality and other species.

It was intentionally introduced as an ornamental plant for water gardens and subsequently escaped. It is still widely available from on-line sellers. 

It can spread when fragments float to new locations. Control is difficult once established. Any attempt at physical or mechanical control will lead to fragments that will root, leading to further infestation. It has been found to be resistant to most herbicides, with those that affect it offering only temporary, somewhat effective control.

The best control method for controlling crested floating heart is preventing infestation in the first place. Water recreationsits should clean, drain and dry their boats, trailers, and equipment to prevent spreading this highly invasive species.

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

Follow this link to learn more about crested floating heart..


Photographer: Ann Murray. Source: University of Florida

NYCR map



More News

South Korea Consults with Texas A&M on Fire Ants
South Korea has asked Texas A&M University for help in stopping an alien pest new to their country, but all too familiar to most Texans. Learn more at ipmsouth.com.

Invasive Plant Internships in Asheville, NC
American Conservation Experience, a Non-Profit Conservation Corps based in Flagstaff, AZ, in partnership with the National Park Service, is seeking TWO Natural Resource Management Interns to dedicate 26 weeks in support of the NPS Southeast Exotic Plant Management Team (SE-EPMT). The purpose of the SE-EPMT is to provide support to partner parks in the management, control, and eradication of invasive, exotic plants and forest pathogens. Learn more at ipmsouth.com.

Citizen Science: A Powerful Tool to Combat Invasive Giant Slugs in Japan
With the help of citizen science, researchers have unraveled the close correlation between weather conditions and the appearances of a giant slug species, enabling them to predict the slug's activity on the following day. Read more at sciencedaily.com.

Florida Working Group Successfully Manages Conehead Termites
An invasive termite, the conehead termite (Nasutitermes corniger), in southeastern Florida is losing its grip on the area, thanks to successful eradication efforts by a multi-agency working group. Learn more about this fascinating pest and the control efforts at ipmsouth.com.

California Aedes Mosquitoes Capable of Spreading Zika
Over the last five years, Zika virus has emerged as a significant global human health threat following outbreaks in South and Central America. Now, researchers have shown that invasive mosquitoes in California -- where cases of Zika in travelers have been a regular occurrence in recent years -- are capable of transmitting Zika. Read more at sciencedaily.com.

Toxic Toad Invasion Puts Madagascar's Predators at Risk, Genetic Evidence Confirms
The recent introduction of the common Asian toad (Duttaphrynus melanostictus) to Madagascar has led to fears that the toxic amphibian could wreak havoc on the island's already severely threatened fauna. Now, researchers report genetic evidence showing that those fears are well founded: virtually all predators native to Madagascar are highly sensitive to toad toxins. If they should eat the toads, it would be a potentially fatal mistake. Learn more at sciencedaily.com.

Invasive Species of Coral Boasts Amazing Capacity for Regeneration
Colonies of sun coral (Tubastraea coccinea and T. tagusensis), multiply rapidly, driving native corals out along the coast of Brazil. Scientists are investigating whether the rising of oceanic temperature, combined with increasing activity of the oil and gas industry, might be favoring the invasive species. Learn more at sciencedaily.com.


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:

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.