Featured Research

from universities, journals, and other organizations

Edge Density Key To Controlling Gypsy Moth Spread

Date:
November 20, 2006
Source:
Penn State
Summary:
Controlling population peaks on the edges of the gypsy moth range may help to slow their invasion into virgin territory, according to a team of researchers.

The Gypsy moth is highly destructive to trees. Pictured here are the adult European/North American female (top) and male (bottom). Introduced in Massachusetts in 1869, the Gypsy moth is a plain-looking insect, usually noticeable in its caterpillar stage. A female moth lays a cluster of eggs on and near trees, and each cluster can hatch up to a thousand tiny caterpillars. They are one of the most destructive leaf eaters of hard and softwood trees, and feed on over 500 species of trees and shrubs.
Credit: USDA APHIS PPQ

Controlling population peaks on the edges of the gypsy moth range may help to slow their invasion into virgin territory, according to a team of researchers.

"Slowing the spread of the gypsy moth is a priority in forest management in the U.S.," says Ottar Bjornstad, associate professor of entomology and biology, Penn State. "Understanding the underlying patterns in the spread of invasive species is important for successful management."

The accidental release of the gypsy moth in 1869 in Massachusetts has led to an infestation covering more than 386,000 square miles of the U.S. Northeast. Native to Europe and Asia, gypsy moths are currently found from Maine to North Carolina and west into Wisconsin where they defoliate trees and occasionally, cause extensive damage to northern deciduous forests.

"We analyzed historical data on the spread of the gypsy moth in the U.S. and found that its invasion has been characterized by regular periods of rapid spread interspersed between periods of little expansion," says Bjornstad. "This is the first identification of pulsed invasions for an invading species."

Bjornstad; Derek M. Johnson, Department of Biology, University of Louisiana, and Andrew M. Liebhold and Patrick C. Tobin, U.S. Forest Service, used historical, county-level quarantine records as well as forest service data from more than 100,000 pheromone traps set along the expanding gypsy moth population front for their theoretical model. The pheromone trap data were collected from 1988 to 2004.

They used a theoretical model to show how an interaction between negative population growth at low densities -- "the Allee effect" -- and the existence of a few satellite seed colonies created by human transfer of the insects over long distances, explain the invasion pulses, the researchers explain today (Nov. 16) in Nature. The gypsy moth adult is flightless and usually only spreads a short distance beyond infestation boundaries. External colonies occur when moths hitch a ride on vehicles or other items relocated by people. Without an Allee effect, these colonies would establish, but because gypsy moths exhibit an Allee effect, the low populations are insufficient for establishment of permanent populations.

This is also true at the edges of the population area. If the population density is low, the Allee effect prevents growth across the boundaries. The model showed that no pulsed expansion exists for populations unaffected by the Allee effect. However, when the it is a factor, not only does pulsed expansion occur, but it mimics the historic pulses of the gypsy moth population from 1960 to 2002 found in the quarantine records.

Currently, the containment program for gypsy moths aims at controlling outbreaks outside the current population boundaries. The researchers suggest that "the invasion might also be slowed by suppressing outbreaks near the invasion front (within the populated area), to reduce the number of dispersers to below the donor threshold." This would decrease edge populations and prevent the periodic surges of growth that expand the territory.

Other invading species may also exhibit pulsed spreading. If researchers can determine that the Allee effect is in place, than this same plan of containment might aid in controlling a variety of pests.

The National Research Initiative of the USDA Cooperative State Research, Education and Extension Service supported this research.


Story Source:

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


Cite This Page:

Penn State. "Edge Density Key To Controlling Gypsy Moth Spread." ScienceDaily. ScienceDaily, 20 November 2006. <www.sciencedaily.com/releases/2006/11/061116084149.htm>.
Penn State. (2006, November 20). Edge Density Key To Controlling Gypsy Moth Spread. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2006/11/061116084149.htm
Penn State. "Edge Density Key To Controlling Gypsy Moth Spread." ScienceDaily. www.sciencedaily.com/releases/2006/11/061116084149.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 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:
from the past week

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