Study Shows Stiltgrass Invasion May Facilitate Invasion by Garlic Mustard

Photo by S. Luke Flory

New results provide experimental evidence that an initial plant invasion associated with suppression of resident species and increased resource availability can facilitate a secondary invasion. Such positive interactions among species with similar habitat requirements, but offset phenologies, may exacerbate invasions and their impacts on native ecosystems.

A study conducted by S. Luke Flory and Jonathan Bauer used a long-term field experiment to test for indirect facilitation by Microstegium vimineum (stiltgrass) on a secondary invasion of Alliaria petiolata (garlic mustard). These species represent two of the most widespread and problematic invasive plant species in eastern North America. They found that Alliaria produced seven times more biomass and nearly five times more fruit in plots that had previously been invaded by Microstegium­. In addition, Microstegium-invaded plots had substantially less resident biomass than controls, and very little Microstegium early in the growing season when Alliaria is most productive, presumably due to the direct effects of Microstegium in prior years. 

Photo by S. Luke Flory

The study experimentally demonstrates that Microstegium can facilitate Alliaria across a range of disturbance regimes. Greater growth and reproduction of Alliaria in Microstegium-invaded plots may be indirectly facilitated by Microstegium’s suppression of shared resident competitors and associated increases in resource availability, although other mechanisms are possible. Understanding how direct and indirect interactions among species, particularly non-native invasive species, might structure communities is a primary need in ecology.

Photo by S. Luke Flory

For a copy of the full article email S. Luke Flory.

Researchers revise Darwin's thinking on invasive species

Researchers revise Darwin's thinking on invasive species

Evidence of possible new invasive species in Great Lakes found

Evidence of possible new invasive species in Great Lakes found: Scientists say genetic material from an invasive fish called the Eurasian ruffe has been detected in southern Lake Michigan for the first time.

Two thousand mice dropped on Guam by parachute — to kill snakes

Two thousand mice dropped on Guam by parachute — to kill snakes

Google Street View for Invasive Species?

Check it out article here and journal article from PLOS ONE here.

Tawny Crazy Ant Found in Southwest Georgia

A UGA Today article by Sharon Dowdy reports that the tawny crazy ant, Nylanderia fulva, has been reported in Dougherty County by the County Extension Agent, James Morgan. They have already been found in Texas, Florida, Mississippi and Louisiana, but this is the first report of an occurrence in Georgia.

Tawny crazy ant, Nylanderia fulva
photo by Eli Sarnat, Bugwood.org

They have also been called crazy raspberry ant. They are referred to as crazy, because they travel in an irregular pattern. Tawny crazy ants have been known to displace all other ant species, including fire ants, in areas they infest. They cause damage by killing small livestock and shorting out electrical systems. In addition they become a nuisance for homeowners, limiting use of  outdoor areas by both people and their pets.

• University of Georgia
• Texas A&M University
• PestWorld.org
• PCT: Pest Control Technology
• University of Texas at Austin

Emerald Ash Borer (Agrilus planipennis) Found in DeKalb and Fulton Counties

EAB Adult: Photo by David Cappaert, Michigan State University, Bugwood.org

Emerald Ash Borer (Agrilus planipennis)
Found in DeKalb and Fulton Counties

EAB Adult: Photo by Marianne Prue, Ohio Department of
Natural Resources - Division of Forestry, Bugwood.org

The invasive forest insect emerald ash borer (EAB), Agrilus planipennis, (Order Coleoptera: Family: Buprestidae) has been found in DeKalb and Fulton counties. The attached announcement from The Georgia Forestry Commission provides an overview of the situation in Georgia. The Center for Invasive Species and Ecosystem Health, University of Georgia, is a member of the Georgia Invasive Species Task Force and has been involved in the development of the announcement and will be providing educational information and educational programming as needed and appropriate.

EAB is a serious tree pest that has caused havoc and has killed multiple millions of ash trees across a wide swath of the upper U.S. mid-West and Canada. EAB kills trees in both rural and urban forests. EAB is a Federally Regulated Pest and thus, there are several actions related to transport of wood products and materials containing wood that are regulated by Federal and State-laws that may be of more significance to Georgia than the potential loss of ash trees.

News Release from Georgia Forestry Commission:

• Destructive Tree Pest Detected in Georgia - August 12, 2013

EAB larvae
Photo by James W. Smith,
USDA APHIS PPQ, Bugwood.org

Adult's exit hole from tree
Photo by David Cappaert,
Michigan State University, Bugwood.org

 Additional Information on EAB:

• 2013 Georgia Fact Sheet
• Frequently Asked Questions in Georgia
• Insecticide Options for Protecting Ash Trees from Emerald Ash Borer
• Additional EAB information and images at Invasive.org
• EAB Information at Georgia Invasive Species Task Force Website
• Forest health alerts & updates on emerging threats to Georgia's forests
• US Federal Quarantine Regulations relating to EAB

How You Can Help Slow the Spread of EAB and Other Tree Pests:

• Don't Move Firewood: Burn It Where You Buy It