Featured Research

from universities, journals, and other organizations

Emerald ash borers were in U.S. long before first detection

Date:
May 7, 2014
Source:
Michigan State University
Summary:
The uber-destructive emerald ash borer arrived at least 10 years before it was first identified in North America, new research confirms. shows that EABs were feasting on ash trees in southeast Michigan by the early 1990s, well before this pest was discovered in 2002, arriving inside wood crating or pallets imported from Asia where the beetle is native.

New research at MSU shows that the uber-destructive emerald ash borer arrived at least 10 years before it was first identified in North America.
Credit: Kurt Stepnitz

New research at Michigan State University shows that the uber-destructive emerald ash borer arrived at least 10 years before it was first identified in North America.

The study, published in the current issue of journal Diversity and Distributions, shows that EABs were feasting on ash trees in southeast Michigan by the early 1990s, well before this pest was discovered in 2002, said Deb McCullough, MSU professor of forest entomology.

"We suspect they arrived inside wood crating or pallets imported from Asia where the beetle is native," she said. "There were probably only a few live beetles that arrived, but ash trees are common in urban landscapes as well as in forests. When they emerged, there were likely ash trees nearby, providing food for the beetles and their offspring."

Slender cores were collected from the trunk of more than 1,000 ash trees across six counties in southeast Michigan. By studying the tree rings on each core and identifying key "marker" years, the team was able to determine the year each tree was killed by emerald ash borers. This study, which encompassed more than 5,800 square miles, is by far the largest area sampled with tree rings. In addition, this was the first study to use tree rings to track the spread of an invasive tree-feeding insect.

The scientists found ash trees were killed as early as 1997. Since it takes many years before the beetle population was large enough to kill ash trees, the team concluded that the invasive species had been in southeast Michigan since 1992 or 1993 and perhaps even earlier.

Emerald ash borers now have infested at least 22 states and two Canadian provinces and have become the most destructive and costly forest insect to ever invade North America, McCullough said.

"Emerald ash borers are killing trees so fast across such a large geographic area, that nobody actually knows how many trees are dead," she said. "We do know there are tens of millions of dead ash in lower Michigan alone."

Data from the tree ring study showed how the infestation grew and spread. Some of the spread was natural -- adult beetles flying from one ash tree to another. However, new "satellite" populations were started by people transporting infested ash trees from nurseries or as logs and firewood. By 2003, they had expanded beyond the six counties encompassed by the tree ring study.

Part of the problem was the difficulty of detecting new infestations, said McCullough. Ash trees have no symptoms when they are first infested. By the time a tree is declining, at least three or four generations of beetles have emerged and gone off to colonize new ash trees.

In addition, reports of declining ash trees were not uncommon in Michigan and surrounding states in the 1990s. Problems ranged from road salt to drought to changing water tables. When shiny green beetles emerged from dying ash trees, however, researchers knew it was something out of the ordinary.

Specialists at the Smithsonian Institute and London's Museum of Natural History could not identify the beetles. Eventually, an entomologist in Slovakia, who intensively studied these and similar beetles, was able to identify the specimens. Still, the species had no common name until the MSU entomologists and their colleagues came up with "emerald ash borer."

By the time Michigan identified the invader, ash trees across southeast Michigan were dead or dying, McCullough said. "We think emerald ash borers probably arrived from China, where they attack only very stressed or dying ash trees. Because of that, they are not considered an important pest in China. The Asian ash species have evolved with the beetles so healthy trees there are resistant to them. In North America, emerald ash borers would still prefer to attack stressed trees but it will do fine on healthy trees, too."

The latest news is featured at www.emeraldashborer.info, which is housed at MSU. The site features current research, which is exploring improved methods to detect new populations as well as identifying natural enemies of emerald ash borers imported from China that may become effective biocontrol agents.


Story Source:

The above story is based on materials provided by Michigan State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nathan W. Siegert, Deborah G. McCullough, Andrew M. Liebhold, Frank W. Telewski. Dendrochronological reconstruction of the epicentre and early spread of emerald ash borer in North America. Diversity and Distributions, 2014; DOI: 10.1111/ddi.12212

Cite This Page:

Michigan State University. "Emerald ash borers were in U.S. long before first detection." ScienceDaily. ScienceDaily, 7 May 2014. <www.sciencedaily.com/releases/2014/05/140507132746.htm>.
Michigan State University. (2014, May 7). Emerald ash borers were in U.S. long before first detection. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2014/05/140507132746.htm
Michigan State University. "Emerald ash borers were in U.S. long before first detection." ScienceDaily. www.sciencedaily.com/releases/2014/05/140507132746.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins