Insects, both beneficial and disruptive, have always been front-of-mind for the people growing our food. Of particular interest in today’s world are invasives: insects that are not native to a region and whose introduction (whether intentional or accidental) is likely to cause harm to our environment, our economy or human health. Or already has.
A 2016 report in Nature Communication estimates that the annual economic impact of invasive insects on goods and services in North America is at least $27.3 billion. And this, say the authors, is likely an underestimation because determining the economic impact of invasives can be particularly difficult. “Most cost estimates are disparate, regionally focused, cover variable periods and are not always grounded in verifiable data,” write the authors. Additionally, the spread and the impact of invasive insects is likely to increase in coming years due to climate change, rising human population densities and intensifying international trade. But, say the authors, there is a way to minimize the impact: increased surveillance, containment and public awareness. In other words: To protect our local farmers, food systems and economies, we – the general public – need to pay attention to the bugs around us.
In the Microbial Sciences Building at the University of Wisconsin-Madison, the incredibly efficient eating habits of a fungus-cultivating termite are surprising even to those well acquainted with the insect’s natural gift for turning wood to dust.
According to a study published today (April 17, 2017) in the journal Proceedings of the National Academy of Sciences, when poplar wood undergoes a short, 3.5-hour transit through the gut of the termite, the emerging feces is almost devoid of lignin, the hard and abundant polymer that gives plant cells walls their sturdiness. As lignin is notorious for being difficult to degrade, and remains a costly obstacle for wood processing industries such as biofuels and paper, the termite is the keeper of a highly sought after secret: a natural system for fully breaking down biomass.
“The speed and efficiency with which the termite is breaking down the lignin polymer is totally unexpected,” says John Ralph, a UW-Madison professor of biochemistry, researcher at the Great Lakes Bioenergy Research Center (GLBRC) and lignin expert. “The tantalizing implication is that this gut system holds keys to breaking down lignin using processes that are completely unknown.”
By Dennis Pillion
A full-grown Southern pine beetle is still about half the length of a grain of rice, but state and federal forestry officials worry this tiny bug could have a monster impact this year on the state of Alabama’s $11 billion wood products industry.
“With Southern pine beetles, the Latin name (Dendroctonus frontalis) actually means tree killer, and it is,” said Edward Loewenstein, associate professor of silviculture at Auburn University’s School of Forestry and Wildlife Sciences. “It is well-suited to take trees out.”
This year’s concerns are rooted in the large number of trees left stressed or already dying from last year’s record-setting drought. Drought-stressed trees don’t make sap as well as healthy ones, and that sticky sap is the tree’s primary defense against beetles.
By Holly Ramer, Associated Press
They may be down but they’re not out: Damaging insects can emerge from fallen trees and logs for several years after a major storm, according to a U.S. Forest Service study that reinforces long-standing warnings against moving firewood from place to place.
Timber that gets blown down, broken or damaged by wind is often cut and used as firewood, which in turn can enable the spread of invasive, destructive insects that drain the life out of forests from New England to the West Coast.
Such pests are projected to put 63 percent of the country’s forest at risk through 2027 and carry a cost of several billion dollars annually in dead tree removal, declining property values and timber industry losses, according to the peer-reviewed study last year in Ecological Applications.
Researchers were surprised to find that wood harvested even three years after the tornado produced a significant number of insects.
By Deanna Weniger
The emerald ash borer has proved an elusive foe to conservationists. It hides in the tree tops and its larvae stow away under the bark of the ash tree, making early detection difficult.
Scientists have tried a host of methods — purple sticky boxes, yellow pan traps and bark stripping — in a desperate effort to stop the destruction of the invasive wood boring beetle that has killed tens of millions of ash trees in over 20 states.
While the beetle can hide from humans, it’s not as good at hiding from natural predators, such as the smoky-winged beetle bandit, also known as Cerceris fumipennis.
The University of Minnesota Extension office is looking for volunteers to locate and monitor these harmless wasps that build their nests in sandy soil.
Release by University of Exeter
Ash trees which can resist the killer dieback fungus may be more vulnerable to attacks by insects, according to new research.
Scientists from the universities of Exeter and Warwick examined trees which are resistant to ash dieback and – unexpectedly – found they had very low levels of chemicals which defend against insects.
With efforts under way to protect ash trees from dieback, the scientists warn that selecting trees for fungal resistance could put them at risk from insects.
Aside from ash dieback, the other major threat to European ash trees is the Emerald Ash Borer beetle, which has already devastated vast tracts of ash in the USA and is currently spreading westwards across Europe.
By NPT Staff
One strategy to control the spread of mountain pine beetles in Banff National Park sometimes does the opposite, a study by a University of British Columbia researcher shows.
While pheromone baiting followed by tree removal — purposefully attracting the pests to a tree, which is then cut down in winter when the larvae are trapped inside — can be successful where there is a dense population of beetles, the strategy can increase the number of beetles in some areas of the Canadian Rockies, according to mathematical modeling led by Rebecca Tyson, an associate professor of mathematics at UBC’s Okanagan campus.
“What our study found is that where the beetle population is low, the pheromone is actually attracting more beetles and thus helping the beetle population increase,” said Ms. Tyson, whose research was recently published in ScienceDirect.
By Rowena Lindsay
Hemlock woolly adelgids aren’t native to North America, but droves of them have settled into American forests where they threaten entire ecosystems.
A tiny bug, no bigger than a grain of pepper, is wreaking big-time havoc in US forests, and forest managers are scrambling to keep up.
Hemlock woolly adelgids aren’t native to North America, but droves of them have taken up residence in hemlock forests, from New England to the West Coast, thanks to increased trade and travel. Nestled under the needles of hemlock trees, the invasive insects cut off nutrients to the tree and can eventually take down trees that have stood for 300 years.
If left unchecked, the hemlock woolly adelgid and other pests are projected to put 63 percent of the nation’s forests at risk by 2027, according to a study published this year in the journal Ecological Applications. The tiny invaders could put several species of hemlock at risk for extinction, threatening the biodiversity and stability of ecosystems across the country and cutting a carbon sink for mitigating greenhouse gas emissions.
Globalization has opened the door for hundreds of invasive pests, from the Asian longhorned beetle to the emerald ash borer. And climate change, it seems, will make it even more difficult to evict them.
The Asian longhorned beetle, also known as the starry sky beetle, is native to eastern Asia but has successfully invaded North America and Europe where it infests maple, birch, willow, elm, and poplar trees. An international team of scientists report on the sequencing, annotation, and comparative exploration of this beetle’s genome in an effort to develop novel tools to combat its spread and better understand the biology of invasive wood-boring pests.
Do severe wildfires make forests in the western United States more susceptible to future bark beetle outbreaks?
The answer, in a study published Monday (Nov. 7, 2016) in the Proceedings of the National Academy of Sciences, is no. By leading to variability in the density and size of trees that grow during recovery, large fires reduce the future vulnerability of forests to bark beetle attacks and broad-scale outbreaks.
“Fire creates a very heterogeneous landscape,” says study co-author Kenneth Raffa, professor of entomology at the University of Wisconsin-Madison. “Beetles can only reproduce in an individual tree once, so they take advantage of this patch of trees and that patch of trees as they become available, but when the number and size of trees vary a lot, it’s hard for a large outbreak to develop.”
Read more at: http://phys.org/news/2016-11-variable-tree-growth-forests-future.html#jCp