Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Edge density key to controlling gypsy moth spread

16.11.2006
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.

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>