Findings from the U.S. Forest Service-funded study appear in the February issue of Forest Ecology and Management. The study was conducted in California and Idaho, and showed how applications of laminated flakes containing a substance called verbenone resulted in a three-fold reduction in insect attack rates, compared to areas where they were not applied.
The technique could provide a way to treat infestations on a large scale and limit further spread into millions of acres of trees made vulnerable because of climate change, overcrowding and fires.
It could also be an alternative to insecticides, which can have adverse environmental effects. Thinning of some overstocked forests is still recommended to reduce susceptibility to bark beetles. But, the flakes can provide some protection for the dense, old-growth stands required by wildlife, according to the scientists.
The largest beetle outbreak in North American history is now occurring in Canada, where more than 22 million acres are affected, according to the British Columbia Ministry of Forests and Range. Outbreaks of this magnitude exacerbate global warming by converting forests from carbon sinks to carbon sources.
Scientists have known for more than a decade that one of the safest strategies for deterring such infestations was through application of verbenone, which beetles release to inhibit aggregation by members of their own species, and the Food and Drug Administration has approved for use as a flavor ingredient. But, manual application of verbenone is difficult where infestations cover thousands of acres in remote, steep terrain.
"Verbenone flakes gave significant protection from mountain pine beetles when applied to low to moderate beetle populations," said Nancy Gillette, a Forest Service scientist at the Pacific Southwest Research Station and one of nine researchers involved in the study. "Higher beetle populations will probably require higher application rates."
Gillette and her colleagues speculated that flakes released from the air might better disperse and simulate natural beetle release than large, manually-applied verbenone packets so they used helicopters to release flakes.
They treated 10 plots at two sites, one near Mount Shasta in Northern California and another in Idaho's Bitterroot Mountains. The sites had similar tree densities and existing rates of infestations. Helicopters dropped flakes on half of the plots and left the others untreated, with application rates of about 9.7 flakes per square meter.
The treatments reduced the level of attack to about a third of that in untreated plots in both California and Idaho. Future studies will test a biodegradable formulation of the flakes.
The study, "Aerially Applied Verbenone-Releasing Laminated Flakes Protect Pinus Contorta Stands From Attack by Dendroctonus Ponderosae in California and Idaho" can be seen in the journal Forest Ecology and Management at: http://dx.doi.org/10.1016/j.foreco.2008.12.017
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
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...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine