At first glance, the University of Vermont’s Plant Diagnostic Clinic and the U.S. Centers for Disease Control and Prevention seem to have little in common beyond their soundalike acronyms. While the CDC has an annual budget of more than $6 billion and employs thousands of scientists worldwide, the PDC operates on less than $90,000 a year and has just one full-time scientist serving all of Vermont.

But the two organizations have similar missions. Like the CDC, the PDC is always on the lookout for new and invasive biological agents that can infiltrate the food supply, harm human health and devastate the economy. It, too, must work quickly to identify new bugs, fungi and bacteria to contain outbreaks and minimize their impact. And, the PDC also relies on a network of far-flung experts in the field who keep their eyes and ears to the ground, sometimes literally, to detect the first signs of trouble.

The PDC’s lead investigator is Ann Hazelrigg, a plant pathologist and 25-year veteran of the UVM Extension. Like every land-grant university in the country, UVM has a federally supported plant diagnostic clinic whose mission is to help commercial growers and home gardeners identify and treat the thousands of pests that can ruin their crops, ardens and landscaping. The UVM Extension provides this educational service at little or no cost to the public.

Hazelrigg wears many hats in her job, including overseeing Vermont’s Master Gardener Program. In the war against invasive species, Vermont’s 900 or so active master gardeners are Hazelrigg’s volunteer soldiers. Often the first to spot new blights and insects, they receive “first detector training” in how to proceed when they come across something of interest or concern.

The PDC gathers intelligence rather than making policy. Unlike the Vermont Agency of Agriculture, it has no regulatory authority to issue a stop-sale order when, say, batches of tomatoes with “late blight” show up in Vermont’s big-box stores and garden centers, as they did last June. Late blight, a fungal disease that afflicts tomatoes and potatoes, is probably best known as the cause of the great Irish potato famine of the mid-1800s, which killed tens of millions of people.

Late blight is no stranger to the Green Mountain State. As Hazelrigg explains, each year it naturally migrates here from the southern United States. It arrives in Vermont by late summer or early fall — hence its name — and can be difficult to treat or control. Last year, late blight showed up very early and spread quickly because of the summer’s unusually cool and wet weather. If you grew tomatoes that year and saw your plants wither and die, chances are good that they were infected with late blight.

“In Vermont, tomatoes are sort of a holy fruit. They embody summer,” Hazelrigg observes.

But that reverence for sweet sungolds and plump beefsteaks probably kept many home and community gardeners from cutting down their infested plants. As a result, Hazelrigg says, late-blight spores spread far and wide across the state, costing Vermont’s commercial tomato and potato growers about $1 million in lost revenues.

Some local farmers point out that their losses would have been even worse if it hadn’t been for Hazelrigg and the PDC. Last summer, she visited scores of farms and greenhouses around the state and provided commercial growers with free identifications, as well as advice on how to stop the blight from spreading to other plants.

“Ann is the best,” says Bob Pomykala, president of the Vermont Vegetable and Berry Growers Association, who also operates the 70-acre Pomykala Farm in Grand Isle with his wife, Jane. “If it weren’t for Ann, we probably wouldn’t be in business. You can bring something to her, and you’ll know the next day whether it’s bad or not.”

Hazelrigg isn’t just watching for pests that destroy crops and gardens easily replaced by the next growing season. She’s also on the lookout for foreign invaders that can set up permanent residence in Vermont and wipe out native species. Two such public enemies are the Asian longhorned beetle and the emerald ash borer. The latter is an exotic beetle that first showed up in Michigan in 2002. Carried in hardwood lumber and often spread inadvertently by people who transport firewood, the ash borer has killed tens of millions of trees in at least 14 states and Canadian provinces, including New York and Québec.

“These big invasive insects are really a major worry for our hardwood forests,” Hazelrigg says. “The emerald ash borer and Asian longhorned beetle could really change our landscape, wiping out our ash trees and maples.”

In one respect, invasive insects are more problematic than diseases, she explains. Vermont’s long, cold winters tend to kill off soilborne pathogens. By contrast, insects are adaptable and can often find warm places to overwinter in Vermont.

And the PDC’s problem of invasive insects is increasing, Hazelrigg adds, for many of the same reasons that the CDC faces a growing threat of novel diseases and viruses. In a globally interconnected world, people and products spread pests of all kinds at an ever-faster pace. Visit many of Vermont’s larger garden centers and you’ll find once-rare cultivars that were imported from elsewhere in the United States and abroad.

Moreover, Hazelrigg says, in the last 25 years she’s seen the effects of global climate change. Certain bacterial and fungal diseases that were once found in Connecticut, New Jersey and the mid-Atlantic states are now establishing footholds in Vermont. Wetter than normal growing seasons in recent years have only exacerbated that problem.

Such blights aren’t just a concern for gardeners and growers, either. As Hazelrigg points out, a recent push to grow organic wheat in Vermont has brought with it a potentially dangerous invader: Fusarium head blight. Caused by the fungus Fusarium graminearum, the disease can cause tremendous declines in both yield and quality. More importantly, though, it produces a mycotoxin that can show up in wheat flour and, in high enough concentrations, be very dangerous to humans.

With mounting threats posed by global warming and invasive species, UVM Extension needs its experts more than ever. But in recent years, Hazelrigg, 55, has noticed another change in the course of her work: a generational shift away from the “Jack-of-all-trades,” such as herself, who have both formal training and hands-on experience in agriculture. Recently, she notes, the Extension lost a full-time plant pathologist and two entomologists to retirement.

These days, many of the students coming up through the agricultural programs have never gotten dirt under their fingernails. Hazelrigg calls them “gene jockeys” because they study the genetic makeup of plants in the lab and can identify bacteria and fungi under a microscope. But many have little or no practical field experience with the natural life cycles of plants.

“That’s a real loss to the Extension,” she says. “And I think that’ll be a problem for land-grant universities in the future.”

It’s not the only loss. Like other government-funded programs, the Plant Diagnostic Clinic has seen its federal dollars dry up in recent years. Although all PDCs across the country got infusions of cash after 9/11 to upgrade their equipment in preparation for a potential bioterrorist attack on our food system, much of that money has gone away. As a result, Hazelrigg has to personally hunt down grants to cover 60 percent of her salary and benefits. That’s time not spent helping gardeners and growers.

But the PDC has another resource at its disposal: conscientious Vermonters. What can “civilians” do to help the PDC and the state’s ag community check the spread of invasive bugs and blights?

To start with, Hazelrigg strongly recommends buying locally grown products when possible, whether you’re starting a vegetable garden, stocking up on firewood, or landscaping your home or business. Some of the most devastating and costly infestations hitch a ride into Vermont from warmer climates via plants grown in large nurseries and on farms in the southern United States. While there’s no guarantee, plants sprouted in the Green Mountain State are less likely to contain these unwanted foreign passengers.

Home gardeners or commercial growers who are having trouble pinpointing the source of a problem often turn to a chemical pesticide. Hazelrigg suggests they first call the Master Gardener Helpline for advice. The PDC works with organic and conventional growers alike: Hazelrigg is both a technical advisor to the Northeast Organic Farming Association of Vermont and an instructor who certifies pesticide applicators. But her preferred approach is to educate the public on integrated- pest-management techniques. In other words, spraying toxic chemicals should be the last resort after all other tools have been exhausted.

Finally, when advice from the helpline isn’t enough to nail down the problem a gardener or grower is wrestling with, Hazelrigg suggests they contact the PDC office immediately. In a typical year, Hazelrigg receives as many as 1000 inquiries, which she addresses in cooperation with other PDCs and experts all over the country. She doesn’t charge commercial growers to identify their blights unless it requires expensive lab tests; home and community gardeners can get a blighted sample identified for a nominal $15 fee.

That’s a bargain. More importantly, samples collected from folks in the field help the PDC get a bird’s-eye view of the health of Vermont’s living environment. “A lot of it requires detective work, but that’s what makes my job fun and interesting,” Hazelrigg says. “It’s always something different, and I’m constantly learning. That’s why I’ve been here 25 years.”