Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biocontrol of wavyleaf thistle being studied in Texas

30.11.2006
BUSHLAND û Wavy leaf thistle was difficult to find along Panhandle highways five years ago. But now the noxious weed can be found moving into pastures, said a Texas Agricultural Experiment Station researcher.

Dr. Jerry Michels, Experiment Station entomologist at Bushland, along with Nagendra Earle, a West Texas A&M University graduate student, began looking at controlling the intruding noxious weed with natural controls about two years ago.

Michels' entomology team travels the highways to Colorado frequently each year to monitor biocontrol work with the U.S. Fish and Wildlife Service. At first, they noticed wavyleaf thistle growing in small clumps along roadsides, Michels said, but in the past few years it seemed to be spreading.

Deciding they wanted to look at possible control measures, he submitted a proposal for a grant to the Joe Skeen Institute for Rangeland Restoration. His team received funding for two years.

In spring 2005, Earle began mapping the infestations across the Panhandle. The highest concentrations were found in the northern Panhandle down to U.S. Interstate 40, he said. Wavyleaf thistle has been found along I-40 from New Mexico to Colorado, but not much to the south.

"Our idea was that it was coming in through vehicle traffic, because it is common in Colorado, Nebraska and Wyoming," Michels said. "Also, thistles love disturbed areas, so any road work could have increased the infestation."

Once it was all mapped, Earle looked for naturally occurring insects that fed off the plant. He found one large beetle that fed on the seed heads, but that beetle was considered an economic pest of sunflowers, so it was undesirable for use as a biocontrol agent, Michels said.

This spring, Earle resurveyed to measure the plant's spread and density, Michels said.

"We're finding it is spreading into pastures and becoming a problem," he said. "We need to continue to monitor it for several years to get a good line on it, but we wanted to start treatments also."

A large patch covering several acres in Hutchinson County was selected as a treatment site, Michels said. Cages were set up with four treatments: no action, mowing, chemical control and biocontrol agents.

The thistle seedhead weevils used for the biocontrol study were collected around Kerrville, where the beetle has been released on wavyleaf thistle with good results, he said. This beetle feeds on the seed heads.

"This preliminary year, the biocontrol seems to be working better than the mowing or chemical control," Michels said.

However, he is going to study a musk thistle rosette weevil used in Colorado to help control musk thistle. This beetle feeds on the root of the plant.

Michels hopes the combination of beetles can control the perennial plant and keep it from resprouting each year.

The musk thistle rosette weevil is found primarily north of Texas where the growing season of thistle is different, Michels said. The problem is trying to gather enough of the beetles in Colorado and bring them to Texas while the plants are still growing.

While the musk thistle rosette weevil hasn't been established in Texas, it has been approved by the U.S. Department of Agriculture for use as a biocontrol. Neither beetle is considered a threat to crops.

"Whenever we do biocontrol work, that is our first concern," Michels said.

The ultimate goal is to get both beetles established in cages on roadside wavyleaf thistle plants at high enough numbers so they can be released around the region to naturally spread, he said.

Another part of the study will be to look at a combination of chemical or mechanical methods with the biocontrol using the beetles, Michels said. The hope is a combination will either kill out the plant or weaken it enough to lessen reproduction.

Dr. Jerry Michels | EurekAlert!
Further information:
http://www.tamu.edu

More articles from Agricultural and Forestry Science:

nachricht Filling intercropping info gap
16.11.2017 | American Society of Agronomy

nachricht Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Antarctic landscape insights keep ice loss forecasts on the radar

20.11.2017 | Earth Sciences

Filling the gap: High-latitude volcanic eruptions also have global impact

20.11.2017 | Earth Sciences

Water world

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>