PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Dartmouth research offers new control strategies for bipolar bark beetles

Dartmouth research offers new control strategies for bipolar bark beetles
2013-01-25
(Press-News.org) Population explosions of pine beetles, which have been decimating North American forests in recent decades, may be prevented by boosting competitor and predator beetle populations, a Dartmouth study suggests.

Bark beetles are the most destructive forest pests worldwide. Management and climate change have resulted in younger, denser forests that are even more susceptible to attack. Though intensively studied for decades, until now an understanding of bark beetle population dynamics—extreme ups and downs—has remained elusive.

The Dartmouth-led study, published in the January issue of the journal Population Ecology, confirmed, for the first time, that the abundance of a certain animal species—in this case the southern pine beetle—fluctuates innately between extremes, with no middle ground.

"That is different from most species, such as deer, warblers and swallowtail butterflies, whose populations tend to be regular around some average abundance based on food, weather, and other external factors," says Matt Ayres, a professor in the Department of Biological Sciences at Dartmouth and senior author on the paper. "They don't appear and disappear in cycles. Rather, they exist in two stable equilibrium states—one of high abundance and the other of scarcity." Once the population pendulum swings toward the high end, it won't quickly or easily swing back.

The new research by Dartmouth scientists and their forester colleagues could provide the means to limit this seemingly bipolar dynamic, keeping the bark beetles at the lower stable population level.

The studies identify the presence of bark beetle competitors and predators (specifically two other beetles) as the predominant limiting factor that can keep the bark beetles at a low, stable equilibrium. The authors suggest that the presence of these competitors and predators could be encouraged as a control strategy.

"The pine beetles produce pheromones, chemical signals, that attract enough competitors and predators to prevent outbreaks," says Sharon Martinson, a member of the research team and first author on the new paper. "Leaving more dead trees in forests can provide habitat for competitor beetles that rarely kill tree, and for predators that eat both beetle species."

The authors suggest that other pest species with catastrophic impacts may also have natural dynamics that include a tipping point between the bipolar population states. By learning what factors control those tipping points, impacts on ecosystems can be averted through monitoring and occasional intervention strategies.



INFORMATION:


[Attachments] See images for this press release:
Dartmouth research offers new control strategies for bipolar bark beetles

ELSE PRESS RELEASES FROM THIS DATE:

Gene mutation immortalizes malignant melanoma

2013-01-25
About ten percent of all cases of malignant melanoma are familial cases. The genome of affected families tells scientists a lot about how the disease develops. Prof. Dr. Rajiv Kumar of the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) together with Prof. Dr. Dirk Schadendorf from Essen University Hospital studied a family where 14 family members were affected by malignant melanoma. The scientists analyzed the genomes of family members and found an identical mutation in the gene for telomerase, an enzyme often called 'immortality enzyme', in all ...

At least 1 in 5 were infected in flu pandemic, international study suggests

2013-01-25
The highest rates of infection were in children, with 47 per cent of those aged five to 19 showing signs of having caught the virus. Older people were affected less, with only 11 per cent of people aged 65 or older becoming infected. The findings come from an international collaboration led by the World Health Organization and Imperial College London, which analysed data from 19 countries, including the UK, US, China and India, to assess the global impact of the 2009 influenza pandemic. The results, published in the journal Influenza and Other Respiratory Viruses, showed ...

Global warming less extreme than feared?

2013-01-25
Internationally renowned climate researcher Caroline Leck of Stockholm University has evaluated the Norwegian project and is enthusiastic. "These results are truly sensational," says Dr Leck. "If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate." Temperature rise is levelling off After Earth's mean surface temperature climbed sharply through the 1990s, the increase has levelled off nearly completely at its 2000 level. Ocean warming also appears to have stabilised somewhat, despite the fact that ...

Put me in, coach! How trained literacy coaches can improve student reading comprehension

2013-01-25
PITTSBURGH—The language and reading comprehension skills of low-income upper elementary-school students—especially English-language learners—can improve markedly if trained literacy coaches engage teachers in conducting interactive text discussions with students, according to a three-year University of Pittsburgh study. The Pitt researchers report in the journal Learning and Instruction that language and reading comprehension showed measurable improvement for young students when their teachers had worked "at-elbow" with content-specific literacy coaches to foster a more ...

Fighting back against citrus greening

2013-01-25
This press release is available in Spanish. U.S. Department of Agriculture (USDA) scientists in Fort Pierce, Fla. are helping citrus growers and juice processors address the threat posed by Huanglongbing (HLB), a disease that is costing the citrus industry millions of dollars each year. Citrus trees infected with HLB, also called citrus greening, usually die within five to 10 years. Fruit on infected trees often falls to the ground before harvest, and fruit that remains on trees may become misshapen and sometimes only partially ripen. Supervisory horticulturalist ...

Diet, parental behavior, and preschool can boost children's IQ

2013-01-25
Supplementing children's diets with fish oil, enrolling them in quality preschool, and engaging them in interactive reading all turn out to be effective ways to raise a young child's intelligence, according to a new report published in Perspectives on Psychological Science, a journal of the Association for Psychological Science. Using a technique called meta-analysis, a team led by John Protzko, a doctoral student at the NYU Steinhardt School of Culture, Education, and Human Development, combined the findings from existing studies to evaluate the overall effectiveness ...

Black silicon can take efficiency of solar cells to new levels

Black silicon can take efficiency of solar cells to new levels
2013-01-25
This press release is available in German. Scientists at Aalto University, Finland, have demonstrated results that show a huge improvement in the light absorption and the surface passivation on highly absorbing silicon nanostructures. This has been achieved by applying atomic layer coating. The results advance the development of devices that require high sensitivity light response such as high efficiency solar cells. This method provides extremely good surface passivation. Simultaneously, it reduces the reflectance further at all wavelengths. These results are ...

DNA and quantum dots: All that glitters is not gold

DNA and quantum dots: All that glitters is not gold
2013-01-25
A team of researchers at the National Institute of Standards and Technology (NIST) has shown that by bringing gold nanoparticles close to the dots and using a DNA template to control the distances, the intensity of a quantum dot's fluorescence can be predictably increased or decreased.* This breakthrough opens a potential path to using quantum dots as a component in better photodetectors, chemical sensors and nanoscale lasers. Anyone who has tried to tune a radio knows that moving their hands toward or away from the antenna can improve or ruin the reception. Although ...

More than 1 brain behind E=mc2

2013-01-25
Two American physicists outline the role played by Austrian physicist Friedrich Hasenöhrl in establishing the proportionality between the energy (E) of a quantity of matter with its mass (m) in a cavity filled with radiation. In a paper about to be published in EPJ H, Stephen Boughn from Haverford College in Pensylvannia and Tony Rothman from Princeton University in New Jersey argue how Hasenöhrl's work, for which he now receives little credit, may have contributed to the famous equation E=mc2. According to science philosopher Thomas Kuhn, the nature of scientific progress ...

National Cancer Centre Singapore scientists discover p53 mutation hinders cancer treatment response

2013-01-25
Reducing the level of mutant p53 gene increases susceptibility to treatment Scientists from the National Cancer Centre Singapore (NCCS) have discovered the workings of the gene that has been hindering treatment response in cancer patients. This discovery was made after 5 years of studying the mutant form of the p53 gene, the major tumor suppressor in humans, which is generally found mutated in over 50% of all type of human cancers. The dominant-negative (DN) effect of the mutant p53 gene in cancers was found to affect the outcome of cancer treatment modalities. DN effect ...

LAST 30 PRESS RELEASES:

Global analysis shows hidden damage from men’s alcohol use

DRI recognizes Ashley Cornish as the 2025 Peter B. Wagner Memorial Award Winner for Women in Atmospheric Sciences

Unlocking the blueprint for a powerful plant-based drug

Bringing modern science to vitamin biology: Isha Jain wins NIH Transformative Research Award

University of Houston scientists learn that rare bacterium ‘plays dead’ to survive

Introduced animals change how island plants spread, new global study finds

Mayo Clinic researchers discover ‘traffic controller’ protein that protects DNA, and may help kill cancer cells

Protein sidekick exhibits dual roles in stress granule assembly and disassembly

New hope for MS

Kennesaw State professor receives grant to study cancer origins

Pain and antidepressant drug combo linked to increased seizure risk in older adults

Cancer researchers shape new strategies for immunotherapy

Physical exercise can ‘train’ the immune system

Calm red brocket deer can learn to "Come" and other commands - but the flightiest, most restless individuals struggle

China, the world's largest tea producer, is predicted to experience increases in land suitable for tea-growing under climate change, with the overall range shifting northwards, per AI modeling study

Composing crews for Mars missions

Early humans butchered elephants using small tools and made big tools from their bones

1,000-year-old gut microbiome revealed for young man who lived in pre-Hispanic Mexico

Bears and pandas in captivity develop significantly different gut microbiomes compared to their wild counterparts, and giant pandas in particular have less diverse microbiomes than their wild counterp

Prenatal and postnatal support apps might not work

Dancing dust devils trace raging winds on Mars

Raging winds on Mars

Real-time biopsies uncover hidden response to glioblastoma therapy

Repeated brain tumor sampling uncovers treatment response in patients with glioblastoma

Novel immunotherapy combination destroys colorectal liver metastases

Farmed totoaba could curb poaching

Avalanches: user-carried safety device increases survival time fivefold

It’s all in your head: Select neurons in the brainstem may hold the key to treating chronic pain

Time-restricted eating can boost athletes' health and performance

Burning issue: study finds fire a friend to some bees, a foe to others

[Press-News.org] Dartmouth research offers new control strategies for bipolar bark beetles