Feral hogs (Sus scrofa) have been a plague for years in Texas, causing environmental harm and over $50 million in annual property and crops damage. Citing the recent decision by the EPA to approve the use of KFHB to control feral hogs, Texas Agriculture Commissioner Sid Miller announced in February that the Texas Department of Agriculture (TDA) would allow the use of Kaput Feral Hog Bait (KFHB) in Texas as a "state-limited-use pesticide". State-limited-use pesticides may only be bought and used by a licensed applicator or someone under the direct supervision of a licensed applicator. Subsequently, a judge blocked the rule change.

KFHB is a hog bait that contains warfarin. As an anticoagulant, warfarin causes animals to bleed to death, usually over several days. It is typically used for controlling rodents. Unlike with other mammals, only a small dose is required to kill a hog (KFHB contains one fifth the amount in rat poison). It is not water soluble, and according to a 2004 EPA report, is metabolized and cleared from a living animal's body relatively quickly. According to that same report, formulations used to control rodents appear to have little impact on birds, although it is unclear how much study has been performed on impacts on avian scavengers.

TDA's decision is controversial. Some consider warfarin inhumane, because it takes several days for the poison to kill an animal, during which the animal suffers. It is also argued that poisoned hogs and their carcasses could pose environmental, human health, and economic problems, because they will contain warfarin. Environmentally, decomposing carcasses could release warfarin into the environment, and predators killing and eating ill hogs and scavengers feeding on carcasses, especially mammals, could be poisoned. Similarly, hunters might risk health problems by eating poisoned hogs. Economically, businesses that process feral hog meat into pet food would be concerned about contaminated meat. In fact, it was a meat processor who obtained the judge's restraining order.

The counterarguments are that first, it is highly unlikely that living hogs and hog carcasses would pose risks to the environment or humans because hogs require very low doses of warfarin to be killed, and amounts in their bodies would be lowered further by the relatively high rate at which it is cleared from the body. Because warfarin is water-insoluble, it would not leach into the environment. Restrictions placed on the use of KFHB by TDA further reduce the environmental risks. Second, KFHB turns hog fat blue, making it potentially easy for hunters and meat processors to tell when a hog has been poisoned. TDA provides a fact sheet with more information, although it provides no citations. A final counterargument is that efforts to control the feral hog population have clearly been unsuccessful, and therefore using KFHB provides another potentially powerful tool, one whose environmental benefits, not to mention the reduction in property and crop damage, would far outweigh the apparently very limited potential harm.

Texas Parks and Wildlife Department is still evaluating TDA's decision. It states, "Texas Parks and Wildlife Department (TPWD) has received numerous inquiries regarding the recent announcement from the Texas Department of Agriculture that the Warfarin-based toxicant, Kaput, has been approved for feral hog control in Texas. TPWD has recognized for many years that feral hogs pose substantial risks due to the damage they cause to wildlife, lands, habitat and crops. While TPWD has supported and encouraged responsible feral hog control management practices, it has not yet evaluated the risks and impacts this toxicant may have on non-target species when used as a means to control feral hog populations. TPWD is in the process of requesting the research information utilized by the EPA in recently approving the use of Kaput as a feral hog toxicant. Once an assessment of the research on Kaput is completed, TPWD hopes to express its position on the risks the use of this toxicant may have on Texas wildlife."

Credit: Texas Department of Agriculture

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

Farmer Troy Fruge of Basile, LA shows how wild pigs have damaged areas of his grain sorghum crop. (Photo by Bruce Schultz, LSU)

In the next week, Earthzine will begin publishing the articles included in the first quarterly theme of the year, Ecological Impacts of Biological Invasion. Article topics include fighting invasives with fire in the Everglades, understanding symbiotic relationships among exotic species in Texas, the role of citizen science in tracking invasives, and why data preservation of exotic species tracking is so important. "We're excited to have so rich a first quarterly theme, and it wouldn't have been possible without the assistance of our theme Guest Editor, Hans Landel of the Lady Bird Johnson Wildflower Center."

The Florida Department of Agriculture has an active biological control program for air potato, Dioscorea bulbifera, that has been implemented successfully throughout Florida, Georgia and Louisiana. The team is trying to identify collaborators throughout the southeastern states where air potato can be found to work with in controlling a noxious weed. Assistance is needed in identifying infestation sites, releasing beetles and monitoring for establishment/impact. If you are interested see this link for more information.

University and USDA Entomologists are teaming up to map the location and population density of a newly invasive insect, the Brown Marmorated Stink Bug (BMSB), Halyomorpha halys. Representative elementary and middle schools in all 48 states are invited to help track the insect in urban environments and put BMSB on the map. Learn more.

See more information on the BMSB below.

Photographer: Susan Ellis, Bugwood.org

Registration is open for the North American Invasive Species Forum, to be held May 9-11, 2017, in Savannah, Georgia. Registration is $200 and includes 3 lunches and 2 dinners. Early Registration and Hotel Block is available until March 31, 2017. Optional Field Trips are available on Thursday Afternoon, May 11 – Saturday, May 13. Space is limited for some trips. The North American Invasive Species Forum is a biennial conference encompassing the interests of professionals and organizations involved in invasive species management, research, and regulation in North America. In addition to the three-day event and the post-forum field trips along the Georgia coast, there will also be a pre-forum workshop on invasive species mapping and data. Click here for more information.

May 9-11, 2017
Savannah, GA
 

There will be a webinar on laurel wilt (Raffaelea lauricola) and the insect that spreads it, the redbay ambrosia beetle (Xyleborus glabratus), 2:00 pm on April 22, 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 how to register for the webinar will be available on the Texasinvasives.org Facebook page.

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

Mighty American Chestnut Poised for Return to America's Forests
Scores of American chestnut, Castanea dentate, seedlings growing in upstate New York are the vanguard in the restoration of what was once the most dominant tree in the eastern forests. The trees carry one gene, added by scientists, that makes them capable of withstanding the invasive blight that wiped out billions of their ancestors a century ago. Learn more at sciencedaily.com.

Scientific Advisory Panel Report on Carcinogenic Potential of Glyphosate Available
The Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel met December 13-16, 2016, to consider a set of scientific issues being evaluated by the Environmental Protection Agency (EPA) regarding EPA’s evaluation of the carcinogenic potential of the herbicide glyphosate. The meeting minutes and final report from the meeting are now available, and offer some very interesting reading.

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.

Sexually Confused Invasive Flies May Send Native Species into Decline
Females of the native fruit fly Drosophila persimilis that have been coerced into sex by invasive males of the wrong species are less likely to reproduce with their own kind later. Invasive species are known to threaten native biodiversity by bringing in diseases, preying on resident species or outcompeting them for food. But these results show invasives pose a risk through unwelcome advances, too. Learn more sciencedaily.com.

Invasive Brown Tree Snake Indirectly Impacting Forest Regeneration in Guam
When the brown tree snake, Boiga irregularis, invaded the island of Guam after World War II, it drove 10 of 12 forest bird species extinct. A new study demonstrates that the loss of the frugivores that helped disperse the seeds of trees indirectly negatively affects the regeneration of trees on the island of Guam over a span of decades. Learn more at sciencedaily.com.

Repellent Emitted by Redbay May Be Key to Fighting Beetles
UF/IFAS scientists might have just tracked down the right scents to help deter a beetle that's been delivering disease and devastation to Florida avocado growers. According to a recently published study, UF/IFAS researchers found that when infected with the laurel wilt fungus (Raffaelea lauricola), redbay trees (a close cousin to the avocado) emit methyl salicylate to repel redbay ambrosia beetles (Xyleborus glabratus), the vector of the deadly pathogen. Read more at ipmsouth.com.

Spotted Lanternfly: A National Pest Alert
The spotted lanternfly, Lycorma delicatula, is an invasive sap-feeding planthopper, first discovered in the United States in Berks County, Pennsylvania in 2014. It is recorded utilizing 67 host plant species in Korea, many of which also occur in the U.S. Given the wide range of hosts upon which it feeds, the spotted lanternfly poses a serious economic threat to multiple U.S. industries, including viticulture, fruit trees, ornamentals and timber. Read more at ipmsouth.com.

Rapid Range Expansion of a New Hybrid Species of Tumbleweed Salsola
Salsola ryanii is a new species that is a hybrid between the invasive species S. australis and S. tragus (tumbleweed or Russian thistle). 10 years after its initial discovery in the Central Valley of California, USA, this new species has rapidly expanded its range, contrary to expectations given its hybrid characteristics. Two potential mechanisms of range expansion are discussed. Read more.

Introduced European Beach Grass Plays Role in Rarity of a Californian Lupine
A four-year study of two congeneric lupines, one rare (Tidestrom's lupine, Lupinus tidestromii) and one common (Chamisso bush lupine, Lupinus chaissonis), growing in the dunes near Abbotts Lagoon in Point Reyes National Seashore in California has yielded possible clues about factors leading to rarity. The study discovered that a native deer mouse, Peromyscus maniculatus, takes the seeds of the rare plant while still attached to the plant. European beachgrass (Ammophila arenaria), originally planted to stabilize the dunes, has had the unintentional side effect of giving the mice cover for nocturnal forays among the lupines. It also outcompetes the Tidestrom's lupine. Read more, for an interesting twist involving the endangered western snowy plover(Charadrius alexandrinus nivosus).

Predatory Lizard Enters Brazil Clandestinely
Anolis porcatus, a species native to Cuba, has been identified in several areas near the Port of Santos on the São Paulo coast, in Brazil. Although native to Cuba, DNA study suggest that these lizards could have come from Florida, where they are also exotic. Its introduction into Brazil may threaten the survival of local lizard populations. 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.

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.

Saturday, April 22, 2017
Location: Williamson County Extension Office (Georgetown, TX)
Contact: Judith Currier

Saturday, July 29, 2017
Location: Jesse H. Jones Park & Nature Center (Humble, TX)
Contact: Rose Belzung Holmes