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The Tennessee Department of Agriculture (TDA) is advising forest landowners to monitor their sassafras trees after detecting new cases of laurel wilt disease in Robertson and Hamblen Counties. In the last quarter of 2019, the disease was detected in trees in Montgomery, Cheatham, Dickson and Williamson Counties. "These new detections of this invasive disease show a significant geographic jump across the state," State Forester David Arnold said. "This is yet another unfortunate example of an invasive pest impacting our forests. Landowners should take caution to prevent the spread of this disease if detected on their property."

Laurel wilt is a fungal disease caused by an invasive pathogen, Raffaelea lauricola, which can affect a range of plants, including sassafras and spicebush in Tennessee. Choked of water, trees wilt and die within a few weeks or months. Currently, no treatment has been developed that can cure laurel wilt disease or protect trees from infection. The best way to prevent the spread of laurel wilt is to avoid movement of firewood or other untreated timber. Tennesseans are urged to monitor their sassafras trees for browning of leaves, leaf loss, and staining in the inner bark. If you suspect your trees might have laurel wilt disease, contact Forest Health Program Specialist Sam Gildiner at 615-837-5439 or sam.gildiner@tn.gov. TDA Division of Forestry staff will assist in identifying the disease and recommending management actions, if appropriate.

ARS scientists at the Plum Island Animal Disease Center in Orient Point, NY, have made two important advancements against African swine fever virus, which causes a lethal disease in pigs.

Humans adores trees. But humans also migrate and trade, habits that led to the accidental introduction of insects and diseases that harm trees and alter the landscape. Examples are easy to find and may be outside your front door: American elms that once dotted streets across America succumbed to Dutch elm disease. Now all colors of ash species – black, green, white, pumpkin, and blue – are threatened by emerald ash borer. The already uncommon butternut tree, also known as white walnut, faces the possibility of extinction from a mysterious attacker. Many invasive insects and fungi come from regions where native trees have evolved to resist their attacks. When these species enter the United States, they find trees that lack this resistance. There's no immediate end to this dismal pipeline, but there is hope on the horizon.

Agriculture Secretary Tom Vilsack today applauded research and protection efforts underway at the U.S. Department of Agriculture’s (USDA) Agricultural Research Service (ARS) and Animal and Plant Health Inspection Service (APHIS) to prevent the spread of African Swine Fever virus, which has been causing devastating losses to the swine industry across the globe. "USDA agencies are working together to protect U.S. livestock from foreign and emerging animal diseases that could harm our economy and public health," said Secretary Vilsack. "I am proud of the extraordinary research underway at the Agricultural Research Service to develop vaccine candidates to prevent African Swine Fever virus. In addition, the Animal and Plant Health Inspection Service has done tremendous work to establish protection zones to safeguard the entire U.S. swine industry."

African Swine Fever (ASF) was originally detected in 2007 in the Republic of Georgia and is known to cause virulent, deadly disease outbreaks in wild and domesticated swine. Since the original outbreak, ASF has had a widespread and lethal impact on swine herds in various countries in Eastern and Central Europe and throughout Asia. Although the virus is causing profound economic losses to the swine industry, there have not been any U.S. outbreaks.

ITP and the APHIS PPQ S&T Beltsville Lab are pleased to announce the release of IDphy: Molecular and Morphological Identification of Phytopthora Based on the Types, ITP’s first pathogen tool. This website offers PPQ and its partners the most complete, valid, and up-to-date resource for identifying the culturable species of Phytophthora. IDphy includes detailed standard operating procedures for all steps involved in culturing, sequencing, and identifying suspect samples, covering both molecular and morphological methods. Some species of Phytophthora are devastating plant pathogens that have a significant impact on agriculture and natural ecosystems.

Effective immediately, the Animal and Plant Health Inspection Service (APHIS) is modifying the conditions under which citrus fruit may be moved interstate from areas quarantined for sweet orange scab (SOS) when destined for processing or packing in a commercial citrus-producing state without a state-wide SOS quarantine.

Scientists from the U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS) have identified a new way to detect the presence of live African Swine Fever Virus (ASFV) that minimizes the need for samples from live animals and provides easier access to veterinary labs that need to diagnose the virus. "We have identified a cell-line that can be used to isolate and detect the presence of the live virus," said ARS Scientist Dr. Douglas Gladue. "This is a critical breakthrough and a tremendous step for African Swine Fever Virus diagnostics."

This research, which is highlighted in this month's issue of Viruses, was funded through an interagency agreement with the Science and Technology Directorate of the U.S. Department of Homeland Security, U.S. Department of Energy and the U.S. Department of Agriculture. A provisional patent application for this research was filed in April 2020 and the technology is now available for license. ARS scientists at the Plum Island Animal Disease Center in Plum Island, N.Y. will continue to perform research and work towards finding tools to control the spread of ASFV in the nation.

A genetic discovery by ARS and University of Florida scientists could speed the search for hybrid citrus trees that tolerate citrus greening disease (Huanglongbing) and produce orange-like fruit ideal for making juice.

New clues to how the bacteria associated with citrus greening infect the only insect that carries them could lead to a way to block the microbes' spread from tree to tree, according to a study in Infection and Immunity by Agricultural Research Service (ARS) and Boyce Thompson Institute (BTI) scientists.

Dogs specially trained by Agricultural Research Service (ARS) scientists have proven to be the most efficient way to detect huanglongbing—also known as citrus greening—according to a paper just published in the Proceedings of the National Academy of Sciences. Currently, the only solid hope of curtailing the spread of citrus greening is to eliminate trees with the disease as quickly as possible to prevent further spread. Early detection of the citrus greening pathogen is crucial because trees can be infected and act as a source to spread the disease months or years before showing symptoms that are detectable by the naked eye. ARS plant epidemiologist Timothy R. Gottwald with the U.S. Horticultural Research Laboratory in Fort Pierce, Florida, discovered that dogs can be trained to sniff out the presence of Candidatus Liberibacter asiaticus, the bacteria that causes citrus greening, with greater than 99 percent accuracy.

The yield losses attributed to Asian citrus greening disease once established can be devastating. If the disease continues to spread unabated in the citrus growing regions of East Africa, the annual value of lost production could potentially reach up to US $127 million over the next ten to 15 years, according to a recent paper published by CABI. The paper, The Asian Citrus Greening Disease (Huanglongbing): Evidence Note on Invasiveness and Potential Economic Impacts for East Africa (Jun 2021) [PDF, 2.9 MB], provides a review of the global literature on Asian citrus disease or huanglongbing (HLB) and estimates its potential economic impact on East Africa. The paper also makes recommendations for biosecurity preparedness, surveillance and management options to help decision-makers and citrus growers.

Provides news updates and other resources. See also: Avian Influenza Surveillance

Understanding how wild birds facilitate the maintenance, reassortment, and dispersal of influenza A viruses (IAV) is key to forecasting global disease spread. The current highly pathogenic avian influenza outbreak in North America highlights the question of how viruses are transported between continents. Recent NWHC research sheds light on this question and the potential role Iceland may play.

A unique program run by the Agricultural Research Service in Fort Pierce, FL, uses specially trained dogs to detect citrus greening in orchards. The canine-detection method has an accuracy rate of 99 percent.

USDA Forest Service researchers are monitoring the effects of white-nose syndrome, a fungal disease from Eurasia that has decimated cave-hibernating bats across the U.S. since its arrival in 2006. "The fungus that causes white-nose syndrome grows on bats in the wintertime. It causes them to wake up during their hibernation and burn their fat reserves," says Phillip Jordan, wildlife biologist. Jordan is among the experts featured in a new video, Bats on the Brink. Forestry technician Virginia McDaniel created and produced the video.

The Michigan departments of Natural Resources and Agriculture and Rural Development today announced the addition of beech leaf disease to the state's invasive species watch list. Invasive species on the watch list have been identified as posing an immediate or potential threat to Michigan's economy, environment or human health. These species either have never been confirmed in the wild in Michigan or have a limited known distribution. Beech leaf disease is associated with the microscopic worm Litylenchus crenatae, a nematode that enters and spends the winter in leaf buds, causing damage to leaf tissue on American beech and European and Asian beech species. Infestations result in darkened, thick tissue bands between leaf veins, creating a striped effect on the leaves, leaf distortion and bud mortality. Trees weakened by leaf damage become susceptible to other diseases and can die within six years. Beech leaf disease has not been found in Michigan. The disease was first discovered in Ohio in 2012. Since then, it has been identified in seven eastern states and Ontario.

Beech leaf disease has now been confirmed in Prince William County – the first detection in Virginia. The disease affects American beech (Fagus grandifolia) trees and is associated with a foliar nematode. Symptoms include dark stripes between leaf veins, thickening and curling of leaves, and canopy thinning. Contact VDOF's forest health program if you see these symptoms. For more information, view this Beech Leaf Disease Pest Alert (Jan 2021) [PDF, 312 KB] publication.

See also: More Information Relating to the First Report of Beech Leaf Disease in Virginia [Aug 2021) [PDF, 951 KB]

Citrus canker, a serious disease of citrus, was recently found on trees in East Baton Rouge and Livingston parishes, according to LSU AgCenter plant doctor Raj Singh. Citrus canker is a highly contagious bacterial disease that was first detected around 1914 in Louisiana and declared eradicated by 1940. The disease is known to cause defoliation, premature fruit drop, blemished fruit and tree decline. Severely infected trees ultimately may stop producing fruit. If you believe your citrus trees have citrus canker, contact the U.S. Department of Agriculture at 225-298-5410 or the LDAF Horticulture and Quarantine Division at 225-952-8100. 

Scientists from the Connecticut Agricultural Experiment Station (CAES) are reporting that Beech Leaf Disease (BLD) has increased dramatically in both severity and distribution in 2022 compared to 2021. First detected in lower Fairfield County in 2019, BLD is now widespread on American beech (Fagus grandifolia) throughout all eight Connecticut counties, with symptoms most severe in Fairfield, New Haven, Middlesex and New London Counties. Given that BLD is now widely established throughout Connecticut, reports of BLD to CAES and DEEP are no longer requested.