Extension News: Plant health Archives

"Beetle Blitz" will recruit and educate citizen monitors

Forest health experts fear that an exotic pest called the Asian longhorned beetle (ALB), which made its way into the U.S. in wooden packing crates from China more than a decade ago, could move into New Hampshire and devastate our forest landscape.

To prevent an infestation, the state's Forest Pest Advisory Committee has planned a "beetle blitz" later this summer and fall to raise public awareness and recruit citizen volunteers to monitor forest and landscape trees for signs of the insect.

Beetle not yet found in N.H.
"So far, we haven't found ALB in New Hampshire," says UNH Cooperative Extension entomologist, Dr. Stan Swier. "But last summer, the beetle was discovered in Worcester, Massachusetts. State and federal officials have mounted a massive eradication program there, expected to last many years and to cost tens of millions of dollars."

First discovered in Brooklyn in 1996, the beetle turned up in other New York sites, New Jersey, Chicago, Toronto before being discovered in Worcester.

Beetle behavior
"The female ALB chews holes in the trunks and branches of many hardwood species--especially maples, but also birch, elm, ash, poplar, willow, horsechesnut, and many more--to lay her eggs," says Swier. "The eggs hatch, and the larvae excavate large galleries inside the tree, disrupting sap flow, weakening and eventually killing it. ALB attacks many hardwood trees, but is most common in maple and birch."

Beetle threatens forest values
"New Hampshire's 4.6 million forested acres provide the scenic natural backdrop for the quality of life we all enjoy," says Swier. "Our timber industries are collectively worth $2 billion and support 21,000 jobs. Forests also help protect our water quality, prevent flooding, provide wildlife habitat, give us our maple syrup industry, and support many recreational activities for both tourists and residents alike.

"Because the beetle attacks many different tree species, scientists fear an infestation could have long-lasting negative impacts on the entire forest ecosystem if it became established over a large area," Swier says.

Prevention: first line of defense
"Prevention is our first line of defense, followed by aggressive eradication programs if the beetle is found," says Swier. "The larva burrows deeply into the tree, making it extremely difficult to control. We currently have no biological control methods for this pest, although the USDA is conducting experiments testing the effectiveness of some insecticides.

"Chemicals reduce the problem on landscape trees but aren't practical in a forest. Chemicals cannot eradicate ALB.
"Once the beetle has been discovered, it becomes a very expensive search-and-destroy operation, involving cutting, burning and chipping." says Swier.

A call to citizen action
"With nearly five million forested acres in New Hampshire, we believe ordinary citizen observers are the most important key to identifying this potential threat," Swier says. "To that end, we're organizing a 'beetle blitz' of citizen awareness programs, beginning with two early-evening "twilight" meetings, August 18 in Manchester and August 25 in Portsmouth, from 5:30 to 8:30."

"Volunteers will sign up to join specific groups for the survey in their community. Each group will survey for ALB the following Saturday morning, by inspecting suitable host trees within a specifically designated grid area for that group.

"Cooperative Extension staff will follow the initial meetings with similar workshops in each of the state's 10 counties over the fall and winter, as well as with a series of train-the-trainer meetings for garden club members, master gardeners, community tree stewards, and others," Swier says.

"As people learn to recognize the adult ALB and its emergence holes, we hope they'll alert the state authorities: the Department of Agriculture, Markets and Food, the Division of Forests and Lands, or their local Cooperative Extension office.

Primary means for distribution: firewood moving in from infested areas
"The primary way the beetle may move into New Hampshire is on firewood," says Swier. "People transport firewood long distances, especially to summer camps. In late May, both State and Federal regulators banned the movement of firewood into government-owned parks and the White Mountain National Forest. We've identified residents of the Worcester area who own property in New Hampshire and sent individual letters to them all, urging them not to bring firewood into the state and to notify us if they have.

For more information

Beetle blitz kickoff workshops, August 18 and 25 Learn more about the threat to forest and landscape trees, how to scout for and identify ALB signs, and how to participate as a citizen monitor.

N.H. Asian Longhorned Beetle Web site

Video clip: Dr. Stan Swier talks about ALB

Contact information
Dr. Stan Swier
Dept Biological Sciences, UNH
Spaulding Hall, 38 Academic Way
Durham, NH 03824
Ph. ( 603) 781-8248 (cell)
Fax: (603) 862-2717
Email: stan.swier@unh.edu

earliest appearance on record; devastating disease spreads fast, kills quickly

Late blight, a devastating fungal disease that infects tomatoes and potatoes, has been confirmed in Maine, upstate New York, Pennsylvania and in several areas of New Hampshire.

Left unchecked, the fungus can quickly wipe out plantings of these popular vegetables.

Premature arrival, probably on infected tomato seedlings
"Late blight usually doesn't strike the Northeast until August," says Extension Plant Health Specialist Cheryl Smith. "Rainy, overcast weather has provided very favorable conditions for development and spread of the disease."

"Some large, nationwide retail stores have apparently sold infected tomato seedlings. If you bought tomato seedlings at one of these stores, check your plants and keep on checking," Smith says.

Symptoms
"Classic symptoms include large, irregularly-shaped, water-soaked, olive-green-to-brown spots on leaves. Under wet or very humid conditions, a slightly fuzzy, white fungal growth may be visible on the underside of the leaf," says Smith." "Leaf lesions begin as tiny, irregularly-shaped dark green or brown spots. Brown to blackish irregular lesions also develop on upper stems. Firm, brown spots develop on tomato fruit, and infected fruit often looks bumpy".

Advice to home gardeners
"The late blight fungus produces many spores, which can travel long distances through the air. It's crucial that everyone who grows potatoes or tomatoes, including home gardeners, is monitoring for late blight to avoid being a source of spores that move on to infect potatoes and tomatoes in neighboring gardens and commercial fields.

"There's no need to take action if your plants show no signs of infection," Smith says. But she urges home gardeners to heed this advice:

• Thoroughly inspect potato and tomato plantings on a daily basis, because late blight moves fast and can be difficult to control once established in a planting.
• Fungicides containing the active ingredient chlorothalonil are fairly effective in protecting plants from infection. Although copper fungicides are an option for organic gardeners, copper is not highly effective. Gardeners don't have access to fungicides effective for controlling the disease once plants are infected.
• Don't attempt to treat infected plants with fungicides, even those labeled for late blight. Fungicides available to home gardeners can't cure plants that are already infected.
• If you see signs of infection, pull all infected plants from the ground, bag them up, and dispose of the bags in the trash. Do not put them in the compost or in a refuse heap.
• Put a few samples (include several stems plus leaves and/or fruit) into a plastic bag and bring it to your County Extension office, but don't wait for confirmation to pull out the infected plants.
• Don't touch healthy plants after handling infected plants until you've scrubbed your hands with soap and water thoroughly.

Cornell University's late-blight photo gallery

Late blight/early blight photos Photos compare late blight with early blight.

Cornell University vegetable disease updates Frequent updates about vegetable diseases in the Northeast, including late blight.

Photo of late blight on tomato leaves by Eric Sideman, Maine Organic Farmers and Gardeners Association.

Bill Lord, UNH Cooperative Extension fruit specialist emeritus, brings his renowned wit and wisdom to the blogsophere with his new blog, Fruit Grower's Journal: A journal of the activities of a typical fruit grower.

Lord, who retired officially in 2003, but has remained active in Extension tree fruit work, says the information in his blog will apply to backyard fruit producers as well as commercial growers. Lord says he'll devote some posts to small fruits, too.

Current posts feature commentary how New Hampshire's fruit trees are enduring the harsh New Hampshire winter; each post then describes a "variety of the week." (The latest: Buerre Bosc pear.)

Widely acclaimed for his hands-on teaching and extraordinary pruning skills, Lord says he ventured into cyberspace because, "The New Hampshire Fruit Growers Association already had a Web site. A blog seemed like another good opportunity to share information, so why not?"

Check out the Fruit Grower's Journal. Lord says he eagerly awaits comments and questions from readers.

Cheryl Smith, UNH Cooperative Extension's plant health specialist recently returned from a trip to Bangladesh where she served as co-instructor for a week-long Plant Disease Diagnosis Training Workshop held at Bangladesh Agricultural University (BAU) in Mymensingh, Bangladesh.

"I've always been interested in international agriculture, sharing my knowledge and expertise to improve the plant disease diagnostic skills in developing nations, particularly in Asia," says Smith. "When my colleague Dr. Robert Wick of the University of Massachusetts asked me to join him for this first-of-its-kind training, I jumped at the chance. The plant disease diagnostic training workshop was the first of its kind ever offered in Bangladesh, or in Southeast Asia for that matter."

Wick and Dr. M. Bahadur Meah of BAU have collaborated as co-investigators on a U.S. Department of Agriculture-Bangladesh Cooperative Research Project aimed at establishing a plant-disease diagnostic clinic at BAU, the first of its kind for all Southeast Asia, and training faculty and staff in diagnostic techniques.

Smith says Wick and Meah hope to develop 8-10 satellite labs throughout Bangladesh, but funding efforts to develop them and train diagnosticians to staff them hasn't succeeded. "We're all hopeful that funding efforts will be successful now that the BAU clinic is up and running and the first group of workshop students have been successfully trained," she says.

"Before this workshop, many Bangladeshi plant diagnosticians relied heavily on visual identification of symptoms with little microscopic examination to identify plant health problems," Smith says. "They haven't had the intensive hands-on laboratory training they needed to work effectively with microscopes and conduct laboratory tests, which provide more accurate diagnoses and more cost-effective, environmentally sound treatments. Rob and I emphasized the importance of making an accurate diagnosis before an appropriate treatment can be prescribed."

Ten students from various Bangladeshi institutions, all with degrees in plant pathology, attended the week-long intensive training. Conducted in English, the workshop included work in clinical pathology, learning the steps to plant diagnosis, proper care and use of microscopes, preparing slides, making culture media, incubating samples for disease microorganisms and identifying pathogenic fungi, bacteria and viruses.

"Working with such a small group of students gave everyone plenty of hands-on experience," Smith says. "Several growers even brought in samples during the workshop, giving the students (and us) a chance to tackle some real-life samples."

A UNH professional development grant helped subsidize Smith's trip. "I consider Rob one of the best diagnosticians in the U.S., if not the world," Smith says. "Working with him on this workshop reinforced and expanded my own skills. Even though the climate and many of the crops grown in Bangladesh are different from our own, the process for identifying pathogens is the same. What I taught and learned in Bangladesh will certainly help me solve plant health problems in my own work at the UNH Plant Diagnostic Lab."

See a slide show of Smith's trip to Bangladesh.