Alan Eaton
Cooperative Extension IPM Coordinator
Ever since he was in grade school, Alan Eaton had a passion for bugs. And indeed, he eventually made his career studying insects, and he is the entomologist with Cooperative Extension at UNH who coordinates the Integrated Pest Management (IPM) program.
"IPM at UNH is a grower-centered program", Eaton explains. "We focus our research and extension work on the growers' main pest problems at the time. Then, our approach is to teach growers on how to do their own scouting for the pests, and to use controls only when needed". Up to five years ago, Eaton trained growers around the state on an IPM program in sweet corn to manage the caterpillars that attack the ears, resulting in reduced spraying of pesticides. Currently, a main focus is on the management of pest and diseases of greenhouse crops, primarily on poinsettia and bedding plants. "We have a collaborative program with colleagues in Maine and Vermont. For the past three years in January, we have run a series of workshops on Greenhouse IPM, and this last year we focused entirely on biological controls of greenhouse pests. The workshops are held as a one-day training session, and we do it on three consecutive days and at three different sites: UNH, UV and in Manchester, ME. Growers love it!" Alan says.
The greatest success, as Eaton sees it, is the apple IPM program applied at the orchards at Woodman and Kingman Farms at UNH. "The IPM program on apples has been a compilation of efforts by entomologists and pathologists in New England", he says. "The orchard management techniques we have developed have resulted in 30 to 40% less usage of fungicides, insecticides and miticides as compared to 20 years ago". From the beginning of April till the end of August, Eaton puts out a weekly newsletter to apple growers and also runs an automatic telephone Fruit Pest Update (ph. 603-862-3763). "Basically it is a 3 minute long time-sensitive message on what is happening right now, for example what pest is out there, it is time to put up the traps for such pest, and so on", he says.
Another more recent success story is the introduction of predatory mites to control pest mites in apples, such as the European red mite (ERM) and two-spotted spider mite (TSSM). "In 1996, Dr. Jan Nyrop of the New York Agricultural Research Station invited me to join a project", Eaton explains. "The idea was to introduce a predator mite Typhlodromus pyri from Geneva, New York, to orchards across New England. This mite attacks the pest mites that feed on apple leaves. The biggest question was, would it survive well in New Hampshire weather? After a year or two in NH test orchards, the answer seemed to be "yes".
The predator mite survived very well and controlled the leaf-feeding mites in four of the five orchards around the state where it was introduced.
Normally, without miticides, the number of pest mites per 100 leaves can exceed 1000. In orchards where the predator mite was introduced, the populations of pest mites were almost non-existent. "It quickly became obvious that the predator mite could save apple growers from spraying a lot of miticides, if the predator could multiply quickly enough, and if we could figure out how to spread the mites around easily", Alan says.
No one has figured out how to rear the mites so they are not commercially available right now. In trials at different orchards, Eaton has tried several methods to spread the predator mites, and has found that the best may be to use special tree bands wrapped around the trunks. The predator mites congregate in them, and later the bands are moved to trees in new orchards.
"I am very enthusiastic about results with this predator mite so far", he says. "Miticides have not been required at all on trees where this mite became established. This has far exceeded my expectations, which were only to reduce miticide use. We now have them in sections of eight New Hampshire orchards, and I brought them to five more in April, 2000".
This biological control has the potential to save thousands of dollars for NH apple growers. Miticides are typically applied once or twice per season on the 3000 plus acres of apples in NH. At $30 to $75 per acre, miticide costs can be high. Simple arithmetic puts potential impacts at $90,000 or more per year. It will take 10 years or more to realize the full potential, since the mites spread somewhat slowly. Negative aspects? There are a few. It might be that a future killer winter will badly knock back the predator mite populations, but that seems unlikely, based on their survival in trials in NH, VT and ME. The growers can also kill the predators by applying certain pesticides. And there is the slow reproduction and spread problem. "The bottom line is that our apple growers are continuing to cut back on pesticide usage. We are all beneficiaries of this work, with plenty of healthy fruit produced nearby for less money, and our environment stays clean and protected", Alan says.
November 2004 Update: The Typhlodromus pyri project shows some gains, but some losses, too (apple blocks taken out of production because of global over-production of apples). The latest project is another biological control effort, aimed at European apple sawfly. EAS makes a long, curving scar on the fruit. It has few natural enemies here, but Eaton has introduced a European parasite to attack it. His collaborator is Dr. Charles Vincent of Agriculture Canada, who has already successfully introduced the parasite to Quebec. The parasite is very selective; it only attacks this species. That (and the fact that it was already in Canada) made it possible for USDA to grant permission to bring it in. Now it will take time to see if the parasite can build up to high levels in the UNH test orchard, and begin to spread elsewhere. Eventually, Eaton hopes to introduce it to other sites in New Hampshire and the Northeast.
* From: Predatory Mites; Cornell Cooperative Extension, Sheet No.123, 1995
