March 2018
Insect Killing Louisiana's Native Cane Discovered in Texas

Across the Mississippi delta lands, roseau cane (Phragmites australis) plays an important role in maintaining the wetlands. "Known for its soil-building prowess, roseau is saltwater tolerant and resistant to flood and drought. When conditions change, roseau holds firm. About 60 percent of its mass lies in its thick roots."1It also helps sediment drop out of the water, building up soil. As a major component of the marshes of the delta, it helps to protect marshes, shipping channels, shrimping and fishing grounds, and oil and gas pipelines. Unfortunately, the cane is being devastated by the roseau cane scale (Nipponaclerda biwakoensis). Discovered only 2 years ago, this insect has spread widely through Louisiana's coastal marshes.

Originally from Asia, the roseau scale is small, only about the size of a grain of rice. It sucks on the sap of the cane, weakening it. Large infestations kill the cane.

And now the little insect has been found in Texas. Louisiana State University wetland scientist John Nyman spotted scale insects in the J.D. Murphree Wildlife Management Area near Port Arthur, about six miles west of the Louisiana border. It is a puzzle as to how the scale got all the way to Texas from southeast Louisiana.

In Texas, the dominant roseau cane variety is an aggressive European strain. As it does along the Atlantic coast and other places, this strain clogs Texas waterways and crowds native plants. So the scale might seem like a welcome check against European roseau. Unfortunately, it avoids the bad roseau and only eats the good. It remains to be seen how the roseau scale will affect Texas marshes.

If you find the Roseau scale, please contact the Texas Parks and Wildlife Department.

Learn more at The Times-Picayune.

1For more on the roseau cane scale in Louisiana, see this article in The Times-Picayune and this information of the Louisiana Department of Fish and Wildlife.
And finally, The Times-Picayune has a fantastic visual guide to the plague killing Louisiana's roseau cane.


Credit: John "Andy" Nyman, Louisiana State University


Infested cane in the J.D. Murphree Wildlife Management Area. Credit: John "Andy" Nyman, Louisiana State University

roseau cane scale map in Louisiana

Credit: The Times-Picayune, The New York Times

Are Fire Ants Worse This Spring Because of Hurricane Harvey?

Rice University ecologists are checking to see if Hurricane Harvey's unprecedented floods gave a competitive boost to red imported fire ants (Solenopsis invicta) and tawny crazy ants (Nylanderia fulva), two of southeast Texas' most important invasive ants. Fire ants in particular are well known to be flood-adapted: they survive by forming floating balls of ants.

"We're conducting monthly pitfall sampling at 19 established sites in the Big Thicket, a national preserve near Beaumont," said Sarah Bengston, an ant expert, co-principal investigator and Huxley Research Instructor of BioSciences. "Rice's team has been working at these same sites for three years, and we know fire ants and tawny crazy ants, which are each invasive species, had begun to penetrate the intact native ecosystems in the park before the hurricane. We now want to know whether Harvey accelerated this invasion process…If the floods cleaned the slate by drowning all the native ant colonies in the area, our hypothesis is that this may provide a competitive advantage to invaders."

Learn more at See also this article from NBC News on the floating balls of ants seen after Hurricane Harvey.

red imported fire ant

Credit: USDA APHIS PPQ - Imported Fire Ant Station,

floating fire ants

A ball of floating red fire ants. Credit: Mike Hixenbaugh, Houston Chronicle via Twitter

7th TIPPC Conference: Submission Open for Abstracts, Symposium Proposals, Student Travel Grant Applications

The 7th Texas Invasive Plant and Pest Conference 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 deadline for submitting symposium proposals is Friday, May 25. The deadline for submitting abstracts and applications for Student Travel Grants is Friday, June 29.

Check back at the conference 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


Invasive Species Spotlight:
Salt Cedar (aka Tamarisk)
(Tamarix ramosissima)

Salt cedar plants are spreading shrubs or small trees, 5-20 feet tall, with numerous slender branches and small, alternate, scale-like leaves. The pale pink-to-white flowers are small and arranged in spike-like racemes. The distinct petals and sepals occur in fours or fives. It is sometimes confused with Roosevelt weed (Baccharis neglecta), but its leaves and flowers are very different.

Salt cedars have long taproots that allow them to monopolize limited sources of moisture by intercepting deep water tables. They disrupt the structure and stability of native riparian plant communities, degrading native wildlife habitat by outcompeting and replacing native plant species, and increasing the frequency, intensity and effect of fires and floods.

Salt cedar spreads vegetatively. In addition, each flower can produce thousands of tiny seeds that are wind dispersed. Seeds can also be dispersed by water.

The leaf feeding chrysomelid beetle, Diorhabda elongate, is being used as a biological control agent. This beetle has caused spectacular mortality of salt cedar in some release areas in the southwest USA. Learn more in this review article (restricted access). Also see the first article in the More News section below.

Learn more about salt cedar.

salt cedar

Credit: Steve Dewey, Utah State University,


More News

Beetle Odor Could Help Tackle Invasive Shrub Tamarisk
Scientists have found that a synthetic version of a pheromone produced by northern tamarisk beetles (Diorhabda carinulata) could be used to double the effectiveness of the beetles in controlling the invasive shrub. Tamarisk (Tamarix ramosissima), or salt cedar, is an invasive plant in Texas (see above). Learn more at

Cutting and Leaving Encroaching Western Juniper May Lead to Increase in Invasive Grasses
Our Texas Invaders program stresses the point that often removing invasive plants requires restoration afterwards. In another example that emphasizes this point, a study conducted in the Northern Great Basin found that without additional restoration efforts, the removal of western juniper (Juniperus occidentalis) led to an increase in invasive grasses. Learn more at

Native "Invasives" Pose Unique Challenges Compared to Non-Native Invasives
The federal definition of "invasive species" focuses only on non-native species. Native species that act like invasive species we call "aggressive native species" to distinguish between the two. "Because of their unique status as both biological heritage and ecological villains, native [aggressives] cannot be shoehorned into the policy frameworks used for managing alien invasive species." Learn more at

Native Wildflowers Bank on Seeds Underground to Endure Drought
Native wildflowers were surprisingly resilient during California's most recent drought, even more so than exotic grasses. Native wildflowers increased the seeds that accumulated underground by 201 percent during the drought. [Emphasis added] Learn more at

Pine Martens Are Helping To Save Red Squirrel by Controlling Invasive Gray Squirrels in UK
For many years, populations of a little red squirrel with cute ear tufts (Sciurus vulgaris), a native of Great Britain, Ireland and Europe, have been in serious decline because of competition for food from an invasive North American gray squirrel (S. carolinensis) and a pox it carries for which the native animal has no defense. Now, new research suggests that native pine martens (Martes martes), also once on the decline, are suppressing the invading squirrels' numbers. Learn more at See also this article in the Daily Mail.

Invasive Beetle Threatens Japan's Famed Cherry Blossoms
Across Japan's capital, delicate pink and white cherry blossoms are emerging. However, the famed blooms are facing a potentially mortal enemy, experts say: an invasive foreign beetle known as the red-necked longhorn beetle (Aromia bungii). Learn more at

Disease-Carrying Mosquito Goes Extinct Following Rat Eradication on Palmyra Atoll
The Asian tiger mosquito (Aedes albopictus) -- carrier of such diseases as dengue, yellow fever, Rift Valley fever, Chikungunya and Zika -- appears to have vanished from Palmyra with the eradication of the black rat (Rattus rattus). Learn more at

Uncoordinated Trade Policies Aid Alien Bee Invasions
Patagonia may lose its only native bumblebee species due to invasions by alien bee species sanctioned by government policy. The non-native bumble bees also promote the spread of invasive plants. 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:

Friday, April 20, 2018
Location: Phil Hardberger Park Ecology Center (San Antonio, TX)
Contact: Rachel Cywinski

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.