Invasive insects cause at least $77 billion in damage every year, according to a study released Tuesday that says this figure is “grossly underestimated” because it covers only a fraction of the globe.
Climate change is on track to boost the area affected by nearly 20 percent before mid-century, the authors reported in the journal Nature Communications.
Canvassing more than 700 recent scientific studies, researchers looked at the impact of non-native species on goods and services, healthcare and agricultural output.
Most of these studies applied to North America and Europe, which means the devastation wrought by crop-chomping and disease-carrying bugs from afar has not been adequately measured, the authors said.
The most destructive of the insects canvassed was the Formosan subterranean termite, which lives in huge colonies and feasts on wooden structures and living trees.
Pine trees in California forests will die out and give way to brush and chaparral, forestry experts warn, unless agencies undertake what one analyst called a “massive effort” to reduce fuels and replant trees. Otherwise, the conversion to chaparral could further increase risk of wildfires and affect the state’s water supply.
A U.S. Forest Service survey, released in June, revealed that 66 million trees—mostly pine species—have died in the southern Sierra alone, due to bark beetle infestations, drought, wildfire and climate change. One question now, experts say, is what will replace those dead trees.
“We know in the Sierra and Sequoia national forests east of Fresno, the beetles have killed at least 85 percent of the entire pine vegetative type and at least 20 percent of the mixed conifer type, which is pine and fir,” said Steve Brink, California Forestry Association vice president of public resources. “By the end of this summer, essentially 100 percent of the pine type will be dead in the Sierra and Sequoia national forests, and you are going to have a massive conversion to chaparral.”
New Brunswick is on the brink of another spruce budworm outbreak and the forestry industry — the largest in the province — is doing everything in its power to prevent massive defoliation like that of the 1970s.
But to control the insect’s population, the province is banking on a different approach than the intensive aerial spraying of the past, according to the research scientist with the Canadian Forest Service.
“We’re trying to do a very surgical targeted, very small areas, instead of treating half the province, which happened during the previous outbreak,” said Johns.
Scientists together with the industry have started treating several hot spots in New Brunswick in the face of a looming epidemic.
Laurel wilt is caused by Raffaelea lauricola, a fungal pathogen transmitted by the ambrosia beetle Xyleborus glabratus. This beetle and fungus are native to southern Asia, and the beetle was first detected in Georgia in 2002. This disease impacts several trees in the family Lauraceae, including redbay, sassafras, pondspice, bay laurel, and avocado. Extensive mortality to redbay has occurred in coastal areas from North Carolina to Mississippi, with detections also occurring inland in Alabama, Louisiana, and Arkansas. Infected trees generally die within months, often showing a full crown of dead, brown leaves. There is no cure once a tree has this disease. Preventing the spread of this disease by transporting firewood is of the utmost importance, as management options are limited. Current management involves sanitation (chipping, burning) of infested material, and chemical treatments may be effective for high value trees.
This fungus may be called many names – including annosum root rot, annosus root rot, or Heterobasidion root rot – and is caused by Heterobasidion irregulare (formerly named Heterobasidion annosum and Fomes annosus). This fungus is present throughout North America, has a very wide host range, and is commonly found in southeastern U.S. forests. The fungus causes root decay, although infected trees may survive for many years after infection. Weakened roots are at an increased risk of windthrow. Infected roots generally show heavy resin leakage, and the spread of the fungus through root grafts may cause pockets of tree mortality. Fungal spores are also spread by wind, and often infect stumps from recently harvested forest stands. Annosum root rot is most common on deep, sandy soils or former agricultural land. Prevention is the best way to manage this disease, but post-treatment of stumps with borax can limit fungal spread.
DEADWOOD — In roughly two decades, the Black Hills mountain pine beetle infestation has decimated approximately 215,000 acres of pine trees in the Black Hills, leaving drastically changed woodlands in its wake.
Designed to reduce fire hazards and promote biodiversity on more than one million acres of public land in western South Dakota and eastern Wyoming, the framework for the major new management plan, is set forth in a document titled the “Black Hills Resilient Landscapes Project.”
An insect responsible for the loss of much of the eastern United States Appalachian region’s hemlock trees has found its way into Michigan. The hemlock woolly adelgid poses a threat to the state’s valuable hemlock stands. A call to action by citizens may be the most realistic path to further detection and control.
Justin Whitehill is hopeful that “we will eventually be able to produce EAB-resistant ash trees by borrowing from other ash trees that have natural resistance. Applying modern genomic technologies to conventional tree-breeding methods has the potential to preserve not only a single species, but a whole genus that is being impacted worldwide.”
Paul Merten has spent nearly a decade chasing down a killer in the Southern Appalachians, armed with no more than a pocket knife and measuring tape.But recently the entomologist with the U.S. Forest Service in Asheville, N.C., has been homing in on the tiny, yet lethal pest with what he hopes is a secret weapon — parasitoids, also known as wasps.Merten and Haywood County Community College forestry student Caroline McGough were deep in the woods on the Appalachian Trail slicing across the North Carolina-Tennessee border last week, unleashing parasitoids in a science fiction-like attack on the emerald ash borer.
Researchers here are hatching a plan to stop the woolly adelgid. A 1-acre plot of forest is the site of a budding insectary, a farm in the trees of the predator beetle Laricobius nigrinus that has been shown in some cases to kill the adelgid.