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State Entomologist Warns About Viruses
Tuesday December 19, 2006
By Ed Barna
The worst problem with 29-year Agriculture entomologist Jon Turmel slide talk for the Salisbury Conservation Commission on Dec. 6 was that only about 15 people came.
Not only is he on the front lines of detecting things like West Nile Virus and Eastern Equine Encephalitis, he has become part of Addison County's history through his work with the Brandon-Leicester-Salisbury-Goshen Insect Control District, the new Lemon Fair district, and now Weybridge's district. And from his work around the state as head of the Ag Department's Plant Industry section, he has gathered plenty of intriguing or hilarious stories to accompany the more serious side of his informative talks.
For instance, although mosquitoes were his main topic in Salisbury, he was asked about the orange-and-black ladybugs which now, like cluster flies, seek to invade homes in the fall for winter shelter. These imported and now wildly successful Asian Ladybugs are not exactly harmful, he said, but they bite when you grab them, they leave yellow stains when you smush them, and when they are poisoned or winter-killed in walls, they stink.
Turmel recalled one lady in Starksboro who called for help. “She was in tears. She thought it was illegal to kill ladybugs.”
He came, and found a ball of Harmonia axyridis-“it looked like a bee swarm in her living room.” Vacuum them up, he advised, or scoop them up and toss them, and whatever you do, seal the cracks by which a few of them came in and then sent out a pheromone signal to attract the others.
But for most people, the really awful invaders have been the ticks, which can spread Lyme disease. Turmel said they are called “deer ticks,” but the white-footed mouse is actually more important as a tick carrier. Nor is it true that looking for a “bull's-eye rash” will let you know you've been infected, because “60 percent of people don't get a bull's-eye rash,” he said.
Fever, aches, and other cold-like symptoms are better indicators, Turmel said. Keep insisting on being tested, because there are still Vermont doctors who are reluctant to believe that Lyme disease has moved up from Connecticut and Massachusetts, though that situation seems to be getting better, he said.
Just to show that it could always be worse, Turmel showed slides of wild animals with fattened ticks ringing their eyes or clinging to their hides. Moose get ticks that bloat up to the size of half dollars.
But here in Vermont and around the world, mosquitoes are the worst, he said. They will account for about one in 17 deaths among people now living, he said. Looking at his watch near the start of his talk, he said that since he had begun, 135 children under the age of five had died of mosquito-transmitted diseases-one every 23 seconds.
There are also some who still think that only a few flatlanders are complaining about mosquitoes, he said. Such nonbelievers ought to go down Bullock Road in Leicester, which has so many mosquitoes after temporary flooding of Otter Creek that he used to get 200 to 300 bites in one minute when he tested such populations by exposing one arm (“Those on the back don't count,” he quipped).
One fellow researcher couldn't believe the mosquito counts that Turmel, fellow entomologist Alan Graham, and their seasonal associates were reporting. So Turmel set out two overnight dry ice traps in Bridport and Salisbury (mosquitoes are attracted to carbon dioxide, which mammals exhale), sent them to the skeptic, and said “You count them. He quit at 34,000”-in each trap.
“We'll win some battles. We won't win the war,” Turmel said. Mosquitoes are phenomenally adaptable and amazingly successful, found from 5,500 feet above sea level down to 1,200 feet below sea level in some mine shafts, he said. There are 37 families (genera) with 3,200 species, including a new species they found this year, bringing Vermont's tally to 44 species.
Each time it floods along Otter Creek or the Lemon Fair, enough Aedes vexans and Aedes trivittatis hatch that if there were enough bats to eat them all, the ground would be covered with bat guano, Turmel said. The eggs live a century or so, he said (groans from the audience) and each hatch releases only a “minuscule” number of those hidden in the mud.
To kill the larvae (“wrigglers”) before they curl up and pupate (“tumblers”), it's necessary to attack them in the first or second of four growth stages, Turmel said. In the heat of the summer, this can be nearly impossible: he has seen Aedes vexans go from egg to adult in five days.
There are mosquitoes that breed in spring pools, woodland tree holes, backyard gutters and birdbaths, flooded hayfields, swamps-anywhere there's standing water, Turmel said. That led someone to ask: what about all those tires that farmers use to hold down plastic sheets that cover their bunker silos of chopped hay or corn?
“They aren't a problem,” Turmel said, because they get too hot. However, once those tires are taken off and piled, the ones on the bottom can become perfect breeding grounds. Farmers are starting to realize this and are making smaller piles that don't create the same problems, he said.
In New Jersey and Massachusetts, every county has its insect control district, Turmel said-and Vermont should be grateful. With modern air travel, someone could arrive in this country carrying one of the microorganisms that mosquitoes spread, and thanks to such tight controls, so far any such transmission (of malaria, for instance) has been stopped.
In Vermont, there has been a good West Nile Virus testing and reporting network, to monitor its presence in animal and human populations, Turmel said. But the federal budget cut 50 percent of its funding, and is set to cut it another 40 percent, he said.
Another example of modern life affecting the mosquito situation has to do with the way the Champlain Valley has learned to expect flooding and mosquitoes shortly after heavy rains upstream in Rutland County. Turmel said that used to happen in two days, but now it only takes a day and a half-because so much land has been paved and covered through development.
Back in the early days of the B-L-S-G District, which began in 1979, manager Art Doty used to say that the way to deal with the area's many swamps (Otter Creek drops one foot in elevation from Rutland to Middlebury, he's been told) was to “drain them and pave them,” Turmel said.
Then came a day Turmel will never forget. They were at the Sanderson Covered Bridge in Brandon to monitor mosquitoes, and the mayflies were hatching everywhere. Doty stood and watched the matured pupal cases float up, break open, and release the winged adults, for about three hours.
“Jon,” he said, “I understand why we have to use (the biological larvicide rather than chemicals).” From then on, Turmel said, Doty was an advocate of preserving the wetlands, while doing what was possible to control the mosquitoes.
For the future, as more insect control districts form, a new type of state funding will be essential, Turmel said. In the past, he was able to get the larviciding done for about $65,000 a year; this past year, it cost about $180,000.
“Your representatives are hard at work,” Turmel said, and the Governor is from the area, and realizes “it's a quality of life issue. We'll see.”
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