Cornell University entomologist Ann Hajek told a national conference earlier this month that when the gypsy moth – whose caterpillars have defoliated entire forests – started spreading westward more than 100 years ago from New England to Wisconsin, its fungal and viral pathogens followed close behind.
"We were pretty surprised," Hajek says. "No one knew how long it took the pathogens to chase their hosts."
The findings are important because gypsy moth populations can develop unpredictably and erratically, with lots of caterpillars eating all the leaves off of most of the trees, Hajek told attendees at the Cornell-hosted Eighth Annual Ecology and Evolution of Infectious Disease workshop and conference, June 3-4, in Ithaca. Land managers, she says, can rest assured that pathogens will follow the migrating moths, providing natural controls.
Gypsy moths are slowly moving west across the United States after being introduced to Massachusetts from Europe in 1869. They migrate slowly because the females do not fly. By tracking the edges of the migration, where population densities are low, researchers have an opportunity to investigate how long it takes their viral and fungal pathogens to catch up, Hajek says.
The fungal pathogen, entomophaga maimaiga, was first reported in 1989 and attacks the caterpillars. The virus, lymantria dispar nucleopolyhedrovirus, which was accidentally introduced near Boston in 1906, also infects gypsy moth caterpillars.
Hajek and colleagues studied "leading edge" populations of moths and pathogens in central Wisconsin in 2005-07. They set pheromone traps west of the migrating population and then traveled east to lay traps to catch the flying males. Once their traps caught more than 74 moths each in single year, there was a more than 50 percent chance of finding the fungus in that area in the following year. When more than 252 moths were trapped in a year, there was more than 50 percent chance of finding the virus the next year.
"Our data show that the fungus spreads into lower density leading edge populations sooner than the virus, but the virus eventually colonizes the populations, too," Hajek says.
Fungal spores actively shoot out of the moth cadavers and disperse in the environment, thereby spreading quickly. The virus spreads from one caterpillar to another, and possibly via parasitoid flies and predators, which is a slower process, she said.
Hajek has also discovered that the efforts of land managers to release the pathogens along the leading edges of spreading moth populations are ineffective and unnecessary. Hajek and colleagues found no association between the release of pathogens nearby and presence of the pathogens among the moths.
"These results suggest that the pathogens are dispersing on their own and land managers don't need to release them in leading edge gypsy moth populations, because they'll get there on their own anyway," said Hajek.
The conference was sponsored by the Cornell University Center for a Sustainable Future, Institute for Computational Sustainability, National Science Foundation and Cornell.
John Carberry | EurekAlert!
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering