Research Report #26— Gypsy Moths and Man-A Story of Mutual Accommodation
For many years scientists and naturalists have been studying and observing the flora and fauna of the Shawangunk Ridge. Foremost among them was Daniel Smiley, for whom Mohonk Preserve’s Daniel Smiley Research Center is named. Dan wrote numerous reports summarizing his observations on various topics. This regularly occurring series will feature some of these reports; some hold tremendous scientific value today and just await an interested researcher to follow up, others showcase a quirky sense of humor or highlight an oddity of nature.
Read the report: Gypsy Moths and Man-A Story of Mutual Accommodation. 1975. Revised 1980. Daniel Smiley.
A Note from Paul C. Huth, Director of Research Emeritus: In the introduction of this Research Report, Daniel Smiley expressed the “….conviction that fear is in part a product of ignorance, and understanding is prerequisite to a durable accommodation between human interests and the natural environment.”
Dan felt that experiencing a “severe infestation” of thousands of Gypsy Moth caterpillars devouring leaves from trees and leaving them nearly bare, abundant droppings from caterpillars heard and seen falling to the ground “like an ominous rain,” and caterpillars crawling on the ground and low vegetation and on all the nearby tree trunks, could literally “be a fearsome experience.” Dan also felt that “no less fearsome is the frequent response,” which included the broadcast application of insecticides or microbial pest control to large forest areas. Repeated, as often as an new outbreak might reoccur.
The Gypsy Moth was deliberately introduced to America almost 150 years ago, in Massachusetts, as a possible commercial experiment that quickly failed. As with many introductions, the aftermath was the disaster. Escaping into the wild, it began to multiply and rapidly spread in mostly deciduous forests as a frontal wave both west and southward. In New York State, around 1920, the first Gypsy Moths were reported on the east side of the Hudson River in Rensselaer County. It is suspected that the big hurricane of September 1938, was, in part, the vehicle for the insect’s transport to the forests on the west side of the river.
Looking back through the detailed Gypsy Moth data in the Archives of the Daniel Smiley Research Center, is a documentary of the extensive field work and observations in the Shawangunks for some 60 years, including population updates, egg mass counts, Mohonk Preserve Research Associate Projects, educational articles by Dan in the bulletin of the John Burroughs Natural History Society, and summaries of population buildups and crashes. As background for his Research Report, focussing on a strategy of “mutual accommodation,” was Dan’s personal experience from the first large outbreak of Gypsy Moths in the late 1950s and the unacceptable response to it.
The first hatched egg masses were found on Undercliff Road in 1956 by Charles Beeler, with the NYS Conservation Department. There were a few visible spots of defoliation on the foothills of the Shawangunks. In 1957, a “considerable infestation” was noted in the areas of Terrace Drive, Woodland Bridge, and in the vicinity of Mohonk Lake by Conservation Department staff.
As part of a national effort to “eradicate” the Gypsy Moth, the USDA implemented an aerial spraying of affected forests with DDT, including some of Mohonk’s forests. Dan reports, that “by arrangement in advance, Mohonk Lake was not sprayed, yet within a few days I collected a number of dead fish and other aquatic organisms. Presumably this kill came from (spray) drift.”
The next big Gypsy Moth population build up started in 1964, with “wide-spread defoliation in the Shawangunks and in the foothills of the Catskills.” The next year, 1965, there was very heavy defoliation. Dan notes,
“now at the end of June….thousands of acres of woodland in Ulster County are without leaves, and look nearly as brown as in early April! Where homes are located in these areas, people are outdoors for recreation, large fuzzy caterpillars drop down their necks. It’s a real problem, in which biology, economics, and emotion become involved.”
Dan noted that public agencies look at the “facts” and, hearing loudly from constituents, feel that spraying is the only way to go. “Naturalists and conservationists study the same “facts” and conclude that spraying is not [the answer].” Spraying at best is a temporary control, does not eradicate the Gypsy Moth, and was usually applied after much of the aesthetic damage was done. Also, at the time, mounting and alarming evidence was building of the extensive negative affects of pesticides like DDT. As a result, Mohonk made a bold decision to implement a no spray policy.
Dan acknowledged that the evolution of a philosophy of accommodation “to meet the Gypsy Moth problem did not develop with a flash of insight….(but was) first made on the basis of a hunch.” An educated “hunch” of course, reinforced by Dan’s life long observation of Shawangunk species and ecosystem processes, and the shared experience and field work of a considerable number of researchers and naturalists. Over the years, it was found that many species of insects, like parasitic wasps, birds, and mammals responded to Gypsy Moth population spikes. Spraying interrupts and “delays the ultimate accommodation.” And, in more recent years, potent viral, fungal, and bacterial diseases have also devastated population outbreaks. “Thus a new web of interrelationships is being formed within the ecosystem.” Dan acknowledged that in major Gypsy Moth defoliations, the resources expended by trees triggered to re-leaf a second time in the same year severely stressed, and in drought times, ultimately killed some trees like mature Chestnut Oaks. This has been recorded in Mohonk Preserve forests after a number of Gypsy Moth outbreaks, but was felt acceptable as natural change in our culturally evolved forests.
This important and timely Research Report was again brought forward in 1990 when I was contacted by writer Bonnie Marranca as part of her creative work to assemble a new book entitled “Hudson Valley Lives, Writings from the 17th Century to the Present” (The Overlook Press, Woodstock, N.Y., 1991). After a visit and discussion about Dan’s life long work in the Shawangunks, she felt “Gypsy Moths and Man-A Story of Mutual Accommodation” captured the essence of “knowing where you live.” Of the 45 selections profiled, Bonnie placed Dan’s paper in section five, “Natural Histories,” with other writers like John Burroughs, Hector St. John de Crèvecoeur, Theodore Gordon, Peter Kalm, Alf Evers, Cadwallader Colden, Albert Butzel, and Adriaen van der Donck. Of Dan, Bonnie noted that Dan “followed in the tradition of 18th century self-trained naturalists, such as John Bartram, and Thomas Jefferson, and later Thoreau, who watched and recorded natural life in one place, over a long period of time.” Of this Research Report, it “illustrates Smiley’s approach to all aspects of the ecosystem, with some surprising comparisons on pesticides and natural predators in the life of the Gypsy Moth.”
Read the report: Gypsy Moths and Man-A Story of Mutual Accommodation. 1975. Revised 1980. Daniel Smiley.
