December 2016
Tawny Crazy Ants So Bad, Some Wish for the Return of Fire Ants

Yes, that’s right. In some places in Texas, the invasion of tawny crazy ants (Nylanderia fulva) is worse than the red imported fire ants (Solenopsis invicta) that it has replaced. Yes, that’s right, too: the crazy ant displaces the fire ant. Both are from South America, where they naturally compete and are kept in check by the full ant community there. The crazy ant has evolved resistance to the fire ant’s venom, which combined with its ability to form large, multi-queen colonies and the absence of other population control factors, allows them to outcompete the red fire ant here in Texas.

It's the crazy ant’s ability to form huge colonies, rather than a sting or bite, that makes it such a nuisance. It will nest in any cavity and literally take over buildings, swarming inside and wreaking havoc with electronics, air conditioning units, and wiring. Outside, "they drive out almost all other bugs, including spiders, through sheer weight of numbers… Even nesting songbirds can be overrun by crazy ants."

In order to learn more about the crazy ant as part of efforts to control it, researchers at the University of Texas Brackenridge Field Laboratory (BFL) are focusing on its behavior, and on a species of fungus and of phorid fly that are potential biological control agents.

Learn more about the tawny crazy ant and the research at the BFL in this very interesting American-Statesman article.

For video, see these stories on Austin’s KVUE and Dallas’

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 If you believe you have found tawny crazy ants, please report this species. Please also contact your local AgriLife Extension agent, as well.

Follow this link to learn more about the tawny crazy ant.

tawny crazy ant

Credit: Photographer: Bastiaan Drees, Texas A&M University



Research Reveals the Negative Impacts and Other Aspects of Nonnative Forest Insects and Diseases in the United States

A recent study (Here) reviewed and synthesized "information on invasions of nonnative forest insects and diseases in the United States, including their ecological and economic impacts, pathways of arrival, distribution within the United States, and policy options for reducing future invasions. Nonnative insects have accumulated in United States forests at a rate of ~2.5 per yr over the last 150 yr. Currently the two major pathways of introduction are importation of live plants and wood packing material [WPM] such as pallets and crates. Introduced insects and diseases occur in forests and cities throughout the United States, and the problem is particularly severe in the Northeast and Upper Midwest. Nonnative forest pests are the only disturbance agent that has effectively eliminated entire tree species or genera from United States forests within decades. The resulting shift in forest structure and species composition alters ecosystem functions such as productivity, nutrient cycling, and wildlife habitat. In urban and suburban areas, loss of trees from streets, yards, and parks affects aesthetics, property values, shading, stormwater runoff, and human health. The economic damage from nonnative pests is not yet fully known, but is likely in the billions of dollars per year, with the majority of this economic burden borne by municipalities and residential property owners…

"Data from the U.S. Forest Service's National Insect and Disease Forest Risk Assessment indicates that 334 million ha, or 63% of the nation's forestland, are at risk for additional basal area mortality of host tree species, and 24.8 million ha are predicted to experience more than 20% loss of host basal area through 2027... These estimates are conservative because they are based on projected damage from 13 already-established pests, whereas more than 60 different pests are currently damaging to United States forests … and many new pests are likely to establish in the United States in the coming decades…

“[A] recent analysis indicates that the direct economic impact of nonnative forest insects in the United States is estimated to be at least $2 billion per year in local (e.g., municipal) government expenditures, $1.5 billion per year in lost residential property values, $1 billion per year in homeowner expenditures (e.g., tree removal and replacement), $216 million per year in federal government expenditures, and $150 million in losses to timber owners.” However, this doesn’t include losses due to diseases.

"There are numerous means by which nonnative pests enter the country, but the two most important pathways are global trade in live plants for horticultural use and WPM such as pallets and crates. Global trade is likely to continue to expand, and current policies place the country at high risk for increasing ecological and economic damage by nonnative pests in the future. Although national and international regulations have reduced the international transport of pests, important opportunities exist to strengthen existing policies and bolster our nation's forest pest defense system."

hemlock woolly adelgid

Hemlock woolly adelgid. Credit: USFS

hemlock woolly adelgid damage

Hemlock kill-off. Credit: USFS


USDA-APHIS PPQ Posts WRAs for Five Plants, Including Two Found in Texas

The USDA Animal and Plant Health Inspection Service’s (APHIS) Plant Protection and Quarantine (PPQ) has posted Weed Risk Assessments (WRA) for the following five weed species:

The purpose of a WRA is to evaluate the likelihood that a weed species will escape, naturalize, and spread in the United States, and harm U.S. natural and agricultural resources. All five of these species have been determined to be in the High Risk assessment category.

  • Apera spica-venti (common windgrass) [found in Texas]
  • Chondrilla juncea (rush skeletonweed)
  • Phalaris brachystachys (short-spike canary grass) [possibly found in Texas]
  • Phalaris paradoxa (awned canary grass)
  • Philydrum lanuginosum (woolly frogs mouth)
Link to announcement, with links to each species’ WRA.


Lowering of Lake Austin Will Help Kill Hydrilla

At the request of the city of Austin, the Lower Colorado River Authority will be temporarily lowering Lake Austin by 10 feet. This will allow people living along its banks to repair their docks, shore up retaining walls and remove debris, and the city of Austin to combat invading plants that have flourished at the expense of native ones. The whole process — gradually lowering the lake, performing the various kinds of work and then filling it back up again — should take about a month and a half before likely concluding Feb. 13.

Hydrilla (Hydrilla verticillata) is an invasive plant that arrived in Austin in 1999. It formed thick mats at and just below the surface. By 2012, it occupied about a third of the lake, entangling boat propellers, swimmers and water intake stations. Hydrilla growth was so prolific that it began pushing out native plants. The city hopes that exposing the base of some of the plants to cool air will kill them. The city also plans to plant native vegetation, such as water willow. Read more at

hydrilla on Lake austin


Chris Evans, River to River CWMA,

Conservation Effort Spreads Seeds of Destruction Across the Midwest

Weed scientists in at least two Midwestern states have been reporting for years that a conservation program meant to provide habitat for pollinating insects is sowing bad seeds -- including seeds of the potentially devastating agricultural weed Palmer amaranth (Amaranthus palmeri) -- along with the good. Now, researchers at the University of Illinois have traced the weed seeds to at least one source: pollinator habitat seed sold by a company in the Midwest. Learn more at

Palmer Amaranth in corn field

Dwight Lingenfelter, weed science extension associate in the College of Agricultural Sciences of Penn State, stands next to a Palmer amaranth plant in a corn field. Credit: Penn State

Invasive Spotlight:
Guinea grass
(Urochloa maxima)
(Now considered Megathyrsus maximus)

Guinea grass originates from tropical Africa. It forms dense stands in open pastures and disturbed areas. Guinea grass can suppress or displace local plants on fertile soils in pastures. Its resistance to drought also means it builds up a dangerous mass of plant material so that when fires occur, the blaze is fiercer and native plants, which have not built up fire-tolerance, are wiped out. As guinea grass can survive fires, it can dominate the ground after a fire.

Guinea grass is a tufted perennial, often with a short creeping rhizome, 60-200 cm high, and with leaf blades 10 to 100 cm long and up to 35 mm wide and tapering to a fine point. The sheath is shorter than the internode, and the collar is densely pubescent. It produces open panicles that are 20-65 cm long with whorled lower branches. The spikelets are 3-3.5 mm long. The upper floret (seed) has distinctly transversely wrinkled lemma and palea.

Follow this link for more information on guinea grass.

guinea grass

Credit: Steve Conklin, Invaders of Texas

    guinea grass

Credit: Krystal Watson, Invaders of Texas

More News

Using Sound to Stop Destructive Beetles in Their Tracks
The coconut rhinoceros beetle (Oryctes rhinoceros) has caused significant damage to palm trees in Guam, and it may do the same in Hawaii, where it has been since 2013, if nothing is done to stop it. A team of researchers at the University of Hawaii in Honolulu is using acoustics to help to understand this beetle, its habits and movements in order to protect the state's valuable natural resources. In particular, they hope to develop acoustic methods of tracking the nocturnal beetle. Learn more at

Coconut Rhino Beetles Are Being Moved Around Guam in Commercial Bags of Compost
On Guam, where the coconut rhinoceros beetle (O. rhinoceros) has been destroying palms, it turns out that homeowners have unwittingly been moving the beetles around the island in bags of compost they'd bought at their local nursery or garden center. The beetles find the compost a great place for their eggs and larvae to develop. Learn more at

2017 Imported Fire Ant and Invasive Ant Conference is May 16-18
The 2017 Imported Fire Ant and Invasive Ant Conference will be held May 16-18, 2017 in Mobile AL. The meeting starts with an evening reception on Tuesday May 16. There will be a 2-hour meeting of the Ant Pests eXtension CoP immediately following the conference on the afternoon of May 18. Please bookmark this site so it will be handy: Invasive ant conference.

Is the Arctic Ground Squirrel Non-native on Gulf of Alaska Islands?
The invasive Arctic ground squirrel (Spermophilus parryii) was thought to have been introduced across much of the Gulf of Alaska region as part of the historic fox farming industry. However, using archaeological squirrel remains recovered from middens on Chirikof Island, researchers have found that the squirrel has been on the island much longer. The longevity of the Chirikof squirrel population complicates its classification as an "invasive" or "native" species. Learn more at .

Ash Tree Genome Aids Fight Against Disease
Tens of millions of ash trees across Europe are dying from the fungus, ash dieback (Hymenoscyphus fraxinea). Researchers have successfully decoded the genetic sequence of the European ash tree (Fraxinus excelsior) in an effort to help in the fight against the fungal disease. Knowing the ash tree's genome may also help in stemming the attack of the emerald ash borer (Agrilus planipennis). Learn more at

Carcasses of Invasive Species Provide Food for Invasive Species in Hawaii
Researchers studied the invertebrates and vertebrates that feed on the carcasses of invasive species using camera traps. They found that no native scavengers ate the carcasses, indicating that invasive species provide a "feedback-loop" by providing a source of nutrients for invasive species. Learn more at

Impacts from Introduced Predatory Fish in Panama Still Being Felt 45 Years Later
Since the early 1970s, non-native peacock bass (Cichla monoculus) have been living in Gatun Lake, the reservoir forming the main channel of the Panama Canal, where they have been preying on the native fish. Researchers have found that the abundance of native fishes is greater in lakes that had not been invaded by the peacock bass or another invasive predator, the jaguar cichlid (Parachromis managuesis). Only three of the 12 native species originally found in an un-invaded portion of Gatun Lake were found 45 years later. Learn more Smithsonian Insider.

Sequence of the Whitefly Provides Potential for Control Methods
The genome of the whitefly (Bemis tabici), an invasive insect responsible for spreading plant viruses worldwide and causing billions of dollars in crop losses each year, has been sequenced, providing a potential tool for controlling this pest. Researchers discovered that the whitefly "has acquired 142 genes from bacteria or fungi, including some coding for enzymes that break down foreign chemicals. These genes likely allow the whitefly to feed on diverse types of plants and to rapidly evolve resistance to insecticides." The researchers hope to "develop new varieties of crops that will produce RNA molecules that block the expression of those necessary genes, killing the whitefly or preventing it from spreading viruses." 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 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 designed to help organize and track volunteer-based eradication efforts.

Upcoming Workshops:

March 2017
Stay tuned!

Location: TBA
Contact: TBA

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