University of Illinois ecologist Adam Davis has created a computer model that in combination with quarantined research tests he believes will be able to predict the perfect predator -- a pest that can be introduced into a forested area that will help reduce the garlic mustard population.
“The traditional method has been to release multiple agents into the environment and overwhelm the pest,” said Davis. “But with multiple introductions comes an increased likelihood that one of the agents will become invasive as well. So, what we’re trying to do is to figure out which one is the most likely to actually have an impact on garlic mustard (Alliaria petiolata) and release as few agents as possible.”
Davis is a member of the research team for USDA’s Invasive Weed Management Unit at the U of I. He has been working since 2004 on a project along with scientists at Michigan State, Cornell, and the Commonwealth Institute of Biological Control in Switzerland.
Davis’ computer model creates a simulation of the population dynamics of the pest species – its seed and growth cycle, stressors, etc. “Then you can introduce the biological control agents that you’re considering one at a time and see whether you can get away with just introducing one agent,” said Davis. “I collected data from field experiments and entered them into the computer model which then projects forward which agent will be most effective.”
The computer simulation was used to select a tiny weevil, about the size of an “o” in 12 point type. “There are actually several weevils that feed on garlic mustard back home in Europe, where it comes from,” said Davis. “This particular weevil that we’re looking at (Ceutorhynchus scrobicollis) feeds on the plant at several stages in its life cycle so it’s a much more effective agent than some of the other ones.”
What happens if the control agent also becomes an invasive species?
“A stringent battery of tests is performed on each biocontrol agent in quarantine before it is ever released. For example, garlic mustard is in the same family (Brassicaceae) as cabbage, so one test might be to only feed the weevil cabbage and see if it survives on it or can reproduce on it. If it does, then the possibility exists that it could move from the garlic mustard and threaten cabbage plants, which we don’t want to happen. But, this particular weevil has passed that test for a wide variety of plants.”
Davis said that there are different strategies for biological control. One strategy is inundative in which the control agent eats its way through the garlic mustard and then dies out itself because there isn’t anything left to support it. The other strategy is to introduce a natural enemy that will just bring the population down to a lower level and the plants and pests just continue to coexist. “The idea is that you reunite plants with a natural enemy from back home – which in garlic mustard’s case is Europe. In Switzerland garlic mustard and the weevil coexist and neither one is invasive.”
Garlic mustard was brought to the United States from Europe innocently in the 1870’s as a culinary herb but its natural enemy didn’t accompany it.
Davis says there are some concerns among ecologists about biological control because of the risk of negative effects on nontarget species. “But when you have invasive plant species covering very large acreages it’s almost impossible to manage by hand,” he said. “There are herbicides that will work on garlic mustard, but it infests millions of acres of forest and there’s no way you can get out there and spray all of that. And because garlic mustard has a really long-lived seed bank, in order to eradicate it, you’d have to hit it for about eight to ten years in a row.”
Pending approval from APHIS-PPQ (the species evaluation and quarantine arm of the USDA) the weevil is scheduled to be released into an infested forest later this year. Davis said that the beauty of using simulation models to guide biocontrol is that this approach can be adapted for use in controlling other invasive species, not just garlic mustard.
Debra Levey Larson | EurekAlert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
19.10.2017 | Materials Sciences
19.10.2017 | Materials Sciences
19.10.2017 | Physics and Astronomy