Lack Of Plant Diversity Spurs Cankerworm Damage In Cities

Friday, May 23, 2014
Research from North Carolina State University finds that a lack of plant diversity is a key contributor to the widespread defoliation caused by cankerworms in cities, and highlights the role that increasing diversity can play in limiting future damage.

Fall cankerworms (Alsophila pometaria) are caterpillars that are native to the eastern United States and hatch in early spring. The cankerworms defoliate trees and other plants, eating new leaves as they emerge – which is both unsightly and can ultimately kill the plants.

“We see cankerworms doing more damage to trees in cities than in the wild and examples of widespread cankerworm damage are happening more often,” says Dr. Steve Frank, author of a paper describing the work and an assistant professor of entomology at NC State. “We wanted to know why.”

Dr. Frank looked at two aspects of urban environments that distinguish them from natural environments: the fact that urban environments have less diversity and density of plant life; and the fact that urban areas have more nonnative plant species, such as many ornamental shrubs.

To evaluate the impact of diversity and nonnative species on cankerworm damage, Dr. Frank focused on the damage cankerworms did to understory plants – those plants that grow near or under trees.

“I found that plant diversity plays a significant role,” Dr. Frank said. “Cankerworms did more damage in simple urban environments, where the understory consisted of only a few shrubs, than they did in more complex environments with greater plant diversity.”

Dr. Frank also found a sharp distinction between the impact on native and nonnative plant species.

Native plants were hit particularly hard in simple urban environments. They benefited significantly from complex environments that more closely resembled natural habitat. Nonnative species were largely ignored by cankerworms, regardless of the setting.

“This does not mean that everyone should plant nonnative species,” Dr. Frank said. “The take-home message is that we need to take steps to make urban environments more like natural environments in terms of plant diversity.”

The paper, Bad neighbors: urban habitats increase cankerworm damage to non-host understory plants, is published online in the journal Urban Ecosystems. The work was supported by the U.S. Department of Agriculture under grant number 2013-02476. Additional support came from the Department of the Interior’s Southeast Climate Science Center, which is based at NC State and provides scientific information to help land managers respond effectively to climate change.


TWRA Emphasizes Boating Safety Ahead Of Labor Day Weekend

The Labor Day holiday, the final major weekend of the 2016 summer boating season is Sept. 2-5. The Tennessee Wildlife Resources Agency wants to emphasize the use of life jackets while boating in a safe and responsible manner. The TWRA wants all those who visit the waterways to have an enjoyable time. However, TWRA officers will be on the watch for dangerous boating behavior, ... (click for more)

2016 Dove Season Opens Sept. 1, Early Canada Goose Season Also Begins

Dove season opens on Tuesday, Sept. 1 at noon (local time), which marks the annual start of one of Tennessee’s most long-standing outdoor sports traditions. Tennessee’s 2016 season is again divided into three segments: Sept. 1 through Sept. 28; Oct. 8 through Oct. 30; and Dec. 8 through Jan. 15, 2017. Hunting times, other than opening day, are one-half hour before sunrise until ... (click for more)

Maryville Police Department's Kenny Moats Was The Officer Slain Thursday

Officer Kenny Moats of the Maryville Police Department was shot and killed while responding to a domestic violence call on Thursday.  Officer Moats was with the department for over nine years and was currently serving as a drug enforcement agent. Assistant Commissioner David Purkey said, "It is with heavy heart that I express my condolences to the family and friends of ... (click for more)

Auto Burglary Thwarted In Bradley County

A man has been arrested in Bradley County, after attempting to steal a vehicle. On Thursday, Deputy Jessica Morgan observed a silver truck in a church parking lot on South Lee Highway. While checking the premises, Dep. Morgan observed a male wearing a black tank top and red shorts exiting the rear window of the cab into the bed of the truck. Once the suspect noticed Dep. Morgan, ... (click for more)

Pedestrians Have The Right Of Way - And Response

Often I visit Gold's Gym at Chestnut and 4th Street. I  park in the theater parking lot at Broad and 4th Street.  I depend on the walk signs to get me there safely.  Most days I almost get hit by someone turning left or right coming from the exit ramp off 27 or turning right on 4th street from Chestnut. This happened yesterday as I was almost mowed down by a garbage ... (click for more)

Roy Exum: Abused By An EpiPen

It is a good guess that for about 30 years I have kept an EpiPen on the top of my refrigerator. I have never had to open the box, much less jab a dose of life-saving epinephrine into a person suffering from anaphylaxis. Whether it is a bee sting, peanut butter, shellfish or other allergies, I watched somebody come within inches of dying in my early 20s and swore I would have one ... (click for more)