American Nurseryman Magazine - Horticulture Magazine and Horticulture Books - Plant Health - October, 2013 - DEPARTMENTS

American Nurseryman Magazine - Horticulture Magazine and Horticulture Books - October, 2013

DEPARTMENTS

Plant Health

EAB in Colorado



An emerald ash borer infestation is clearly evident in this suburban parkway tree. Defoliation of the upper branches and a flush of growth on the lower trunk are sure signs of EAB presence.
Photo courtesy of Sally Benson

Emerald ash borer (EAB), the scourge of ash trees in the U.S. since its discovery near Detroit in 2002, continues its march across the country. Its presence now has been confirmed in Boulder, Colo., where it's estimated that 98,000 of the city's trees are ash. The Denver metro area, just a short drive southeast of Boulder, is home to approximately 1.45 million ash trees. The Colorado Department of Agriculture (CDA) estimates that ash comprise 15 percent of the state's urban forest.

According to the CDA, a suspect tree was spotted in Boulder County on September 23 by City of Boulder Forestry staff. Insect specimens from the ash tree were collected and sent to the USDA Systematic Entomology Laboratory, where the identity of the insects was confirmed.

"The confirmation of these specimens as emerald ash borer marks the western-most occurrence of this invasive pest in North America," said Patrick McPherren, USDA State Plant Health Director in Colorado. "To date, Colorado is the fourth state to detect EAB in 2013."

Quarantines will be ordered for the affected area, and additional efforts will include bark inspections and tree sampling, as well as increasing education and outreach programs.

The CDA has been trapping for EAB for five years; this is the first confirmed infestation. It's estimated that EAB has killed more than 50 million ash trees since its initial discovery. In the past 10 years the small, metallic green pest, originally from Asia, has spread from Michigan to 21 states - now including Colorado.

EAB in Georgia

That persistent little devil also has been positively identified in DeKalb and Fulton Counties in Georgia, the first such confirmation in the state, according to the Georgia Forestry Commission. Robert Farris, Georgia Forestry Commission director, says that only 1 percent of the state's forested acres contain ash trees, some 3 million ashes are located in urban environments and another 2 million are in rural settings. Potential losses could reach $1 billion.



Emerald ash borers can be seen lurking in holes in the bark of an ash tree.
Photo courtesy of Debbie Miller, USDA Forest Service; Bugwood.org

Forestry specialists in Georgia have been monitoring for EAB for more than a decade, and have been actively surveying since 2005. The Georgia Invasive Species Task Force is working on a plan to prevent spread of the pest and to educate the public.

For information regarding treatment options, visit http://www.gainvasives.org/eab/Multistate_EAB_Insecticide_Fact_Sheet.pdf.

Earthworms can survive drought

It appears there's hope for the lowly earthworm, even in areas prone to drought. Often incorporated into organic gardens to improve soil structure and productivity, earthworms need moisture for many things, such as respiration (yes, they do breathe), to keep their bodies from dessicating, and to help produce the mucus that allows them to slide through soil. When water is in short supply - as has been the case in many drought-stricken areas of the country - the worms enter estivation, a kind of summer hibernation, during which they curl themselves into a tight ball to conserve moisture. But how long can they last?



Photo courtesy of Joseph Berger; Bugwood.org

Researchers at Colorado State University have discovered that the slimy beasts can survive up to three weeks without significant damage. When soil was rewetted, the worms were able to recover from their dormancy.

More research is planned to determine the ideal length of time for acclimation. Any volunteers?

Read more at: http://www.soils.org/discover-soils/story/earthworms-can-survive-and-recover-after-three-week-drought-stress