November 2019
Florida Researchers Study Insects to Help Control Invasive Brazilian Peppertree

Brazilian peppertree (Schinus terebinthifolia) (BPT) is an invasive plant found along the Texas coast. It has been problematic in Florida for years. Recent research on a biological control agent in Florida may soon lead to a welcome tool for managing BPT here in Texas.

A research team from the University of Florida has been studying the effectiveness of two tiny insects, one called a thrip, Pseudophilothrips ichini, and the other called the yellow Brazilian peppertree leaf-galler, Calophya latiforceps. The research, which has been going on for decades, has found that these two species, also from Brazil, are great candidates as biological control agents because they feed very specifically on BPT. Furthermore, BPT has no native relatives that would be more likely to be susceptible to the insects.

The thrip adults and larvae feed on foliage, which reduces the tree's growth and production of flowers. The leaf-galler's larval stages (nymphs) feed by attaching to the leaf surface and feeding on plant juices. This causes damage including leaf rolling, withering, and gall formation.

This story from NPR describes the release of thrips on a Florida ranch. For more information on the insects, see these articles from the University of Florida, Institute of Food and Agricultural Sciences: thrips and the yellow Brazilian peppertree leaf-galler.

Credit: Stephen D. Hight, USDA Agricultural Research Service,

Brazilian peppertree thrip
Brazilian peppertree thrip adults. Credit: Carey R. Minteer, University of Florida

Calophya latiforceps damage
Brazilian peppertree damage by yellow Brazilian peppertree leaf-galler nymphs. Credit: Rodrigo Diaz, LSU AgCenter

Tawny Crazy Ants' Weird Genetics May Help Them Thrive in New Environments

The Tawny crazy ant (Nylanderia fulva) is an invasive ant that has been spreading in Texas since at least 2002. It causes ecological damage through its foraging and competition with natives, economic damage by destroying electrical equipment, and other urban and rural damages. They are very difficult to control with typical methods.

A team of Texas A&M AgriLife researchers has discovered a pattern of inheritance, apparently unique to the crazy ant, that may have helped the South American species spread in the U.S., and that may allow the development of genetic control methods.

Due to the fact that the ants - like all ants, wasps and bees, - have a very interesting means of sex determination (haplodiploidy), females tend to inherit their mother's versions of genes, and males tend to inherit their grandfather's. As a consequence and due to other mechanisms apparently unique to the tawny crazy ant, females are much more genetically diverse than males, and this may help them withstand the negative effects of inbreeding that occurs when a small population first invades a new area. This diversity does come with a cost, however, as almost 40% of females disappear as eggs.

Furthermore, "We might be able to use the mechanism to drive a lethal gene into the population," said Dr. Ed Vargo, senior investigator of the study and professor of urban and structural entomology in the College of Agriculture and Life Sciences at Texas A&M University.

Learn more at

Credit: Bastiaan Drees, Texas A&M University

Spotted Lanternfly Is Now Officially a Southern Region Pest.

According to Virginia State Extension, "The spotted lanternfly (SLF) [Lycorma delicatula] was detected in Virginia in January 2018. SLF has the potential to be a pest of grapes, peaches, hops, and apples in Virginia. It is commonly associated with tree-of-heaven, Ailanthus altissima. It also has the potential home gardens in Virginia." While not found in Texas yet, it could cause agricultural damage here if it should become established – the tree-of-heaven is planted around Texas and is invasive in some areas.

The Southern IPM Center has compiled a list of resources about how to identify this invasive pest, along with other information.

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

3 Panhandle Counties Participating in $1.4 Million Pilot Program to Help Control Feral Swine

The U.S. Department of Agriculture has awarded more than $1.4 million to fund three pilot projects to control feral swine in three Texas Panhandle counties. These projects are part of the Feral Swine Eradication and Control Pilot Program (FSCP) to help address the threat that feral swine pose to agriculture, ecosystems, and human and animal health.

“Feral swine cause significant damage to crops and grazing lands, while also impacting the health of our natural resources,” said acting NRCS State Conservationist Darren Richardson. “By collaborating with our partners nationally and here in Texas, our hope is to control and eradicate this invasive species - improving operations for farmers while also protecting our natural resources for the future.”

Landowners in these identified counties may be eligible for assistance from trapping technicians to trap feral swine on their property. Interested landowners should visit their local NRCS office.

The Texas pilot projects, which will run from 2-3 years, include outreach and education workshops and demonstrations in each county in the project areas. Texas A&M Natural Resources Institute will assist with monitoring and data collection.

More information, from News Channel 10.

feral hogs and piglets
Credit: Oregon Department of Fish and Wildlife
feral hog crop damage
Credit: Bruce Schultz, LSU

City of Pearland Clarifies What Residents Can Do About Muscovy Ducks

According to an article in The New York Post and a radiobroadcast of The Texas Standard, the city of Pearland released a public notice to clarify that residents can use deadly means to control the invasive Muscovy duck (Cairina moschata):

“Despite Pearland’s status as a bird sanctuary city, a federal control order against the Muscovy ducks supersedes the bird sanctuary ordinance, as well as other federal migratory bird statutes. As such, the general public has the legal authority to address the ducks—including Muscovy duck nests, eggs, and hybrids—on their property, without the requirement of a permit.”

Officials emphasize that residents can only kill a bird if it is captured on their own property -- and the animals cannot be kept, consumed or sold. Furthermore, it’s generally illegal to discharge a firearm within Pearland city limits. If a duck is shot in an area where shooting is allowed, nontoxic shot or nontoxic bullets must be used.

Meanwhile, some residents feed the ducks and even set up kiddie pools for them.

The Houston Chronicle also has an article with more information.

Credit: CC BY-SA 3.0,

muscovy duck problem
Credit: Sophia Germer, The Times-Picayune/

U.S. Sens. John Cornyn (R-Texas) and Ted Cruz (R-Texas) Introduce Legislation Concerning Water Transfer and Invasive Species

"The Public Water Supply Invasive Species Compliance Act [, S.2930,] would provide certainty to water agencies who supply water to Americans in Texas, Arkansas and Louisiana, by ensuring that interstate water transfers between the three states are not shutdown as a result of the Lacey Act, which affects trade in wildlife, fish, or plants across state lines.", according to Sen. Cruz. The Lacey act prohibits the transport of certain invasive species.

"For too long, water providers have had to deal with uncertainty about whether the Fish and Wildlife Service would prohibit them from providing water for Texans' use," said Sen. Cornyn. "This legislation will end the guessing game for local agencies by providing an exemption to the Lacey Act to ensure Texans have a reliable water supply."

According to Sen. Cruz, "The current version builds upon the previously introduced version by ensuring that appropriate actions are taken by the relevant water agencies before water transfers happen. This includes:
  • Notifying the recipient so that they can take adaptive measures in order to minimize and/or mitigate the impacts of invasive species water transfers.
  • Making the water transfer conditional upon implementation of effective mitigation measures should an invasive species be found."

The summary of the House version of the bill (sponsored by Rep. Louie Gohmert [R-TX-1]) reads, "This bill exempts certain water transfers between public water supplies in Texas, Arkansas, and Louisiana from prohibitions on illegal trade of plants and wildlife. Specifically, the prohibitions do not apply to covered water transfers containing a prohibited species if (1) the species are present in both public water supplies before the transfer and the water is transferred directly between them; or (2) the water is transferred in a closed conveyance system, such as a pipe system, and sent directly to treatment facilities where the species will be destroyed."

More information.

US Capitol

municipal water flow
North Texas Municipal Water District. Credit: Tom Fox, The Dallas Morning News

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

Invasive Spotlight:
Elephant Ears
(Colocasia esculenta)

While this plant can live in a well-watered landscape, it is typically found in moist soils along wetland fringes as well as stream, ditch, canal, and lake banks. It forms dense stands, outcompeting native species and thus altering natural habitat and ecosystem processes and reducing biodiversity.

Elephant ears, also called taro, is a perennial herb the leaves of which grow from a thick underground root (corm). The leaves are large: up to 2 m (6.5 ft) tall, with thick petioles making up most of that height and arrowhead-shaped blades to 60 cm (24 in) long and 50 cm (20 in) wide. Leaf margins are wavy, and the upper surface is dark green and velvety.

The inflorescence of elephant ears is on a fleshy stalk shorter than the leaf petioles. The tiny flowers are densely crowded on the upper part of the stalk and enveloped by a long yellow bract (spathe). The female flowers are below the male flowers. The fruit is a small berry, in clusters on the fleshy stalk.

Taro was introduced to the United States from tropical Asia in 1910 as a substitute crop for potatoes. It was later cultivated as an ornamental, and numerous varieties continue to be sold.

For more information on elephant ears, see its species profile.

elephant ears
Credit: Charles T. Bryson, USDA Agricultural Research Service,

More News

Invasive Species Short-Circuiting Benefits from Mercury Reduction in the Great Lakes
According to a new study, 40 years of reduced mercury use, emissions, and loading in the Great Lakes region have largely not produced equivalent declines in the amount of mercury accumulating in large game fish. Researchers say it's largely due to aquatic invasive species in Lake Michigan -- primarily quagga (Dreissena bugensis) and zebra mussels (D. polymorpha) -- that have upended the food web and forced fish to seek atypical food sources enriched in mercury. Learn more at

Invasive Grasses Promote Wildfire in US
In a first large-scale analysis, ecologists report that invasive grasses can double the number of fires. One species, cheatgrass (Bromus tectorum), has a well-earned reputation as a firestarter, making wildfires worse and more common. It is now clear that this involves more than a single species. The new analysis finds at least seven other non-native grasses can increase wildfire risk around the country, some doubling or even tripling the likelihood of fires in grass-invaded areas. Learn more at

Invasive Blue Catfish's Tolerance for High Salinities May Lead to Further Spread
A new study warns that blue catfish (Ictalurus furcatus) -- an invasive species in several Chesapeake Bay tributaries -- tolerate salinities higher than most freshwater fishes, and thus may be able to expand their range downstream into mainstem Chesapeake waters, and from there into new Bay tributaries and even Delaware Bay. Learn more at

The Effects of Ash Dieback and Emerald Ash Borer on European Ash Trees
For the past decade the outlook has been gloomy for European ash trees (Fraxinus excelsior) devastated by ash dieback (Hymenoscyphus pseudoalbidus) and facing the additional threat of the emerald ash borer (Agrilus planipennis) (EAB). However, recent research has found that European ash is relatively resistant to EAB. Learn more at

Unlikely Wasp Enemy of a Serious Alien Pest in North America Named Idris Elba
Idris is a worldwide genus of microscopic, parasitic wasps. A new species of Idris from Mexico (Guanajuato) and the United States (California, New Mexico) proved to be an unlikely enemy of the invasive bagrada bug (Bagrada hilaris), a major pest of various crops, including cruciferous vegetables. 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 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, February 15, 2020
Invaders of Texas Workshop
Location: Houston Advanced Research Center (The Woodlands, TX)
Contact: Teri MacArthur
(not open for registration yet)


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