Wildlife Damage Management, Internet Center for



Date of this Version

February 1978


Published in Proceedings of the Second Eastern Pine and Meadow Vole Symposium, Beltsville, Maryland, February 23-24, 1978, Ross E. Byers, editor. Copyright © 1978.



The Second Eastern Pine and Meadow Vole Symposium met at Beltsville, Maryland, February 23-24, 1978, to discuss various solutions to the serious damage caused by these rodents to fruit trees in the Eastern United States. Fruit growers, local, state, and federal research and extension specialists from many universities, Environmental Protection Agency, U. S. Department of Agriculture, U. S. Department of Interior, and the chemical industry participated in the program.

The purpose of the second symposium was to focus attention on one of the most serious cultural problems facing the fruit industry, to stimulate research, and to seek funds for a national pine vole damage control program. A number of universities reported their work on various aspects of the problem; but because of the lack of funding, the scope and intensity of coordinated research efforts was felt to be greatly needed.

The removal of Endrin by New York State in 1971 provided a classic example of serious farm losses caused by the irresponsible removal of a minor use pesticide with no planned alternate control measure. Since the Hudson Valley was on the northern most border of the pine vole range and because Endrin was being used until 1970, only approximately 7 orchards involving 600-700 acres were known to be infested. By 1977 the vole had enlarged its range to 30 orchards involving 4,200 acres (Warren Smith, personal communication).

In the center of the geographic range (Virginia and West Virginia) the problem had become most acute in the period 1965-1970 because Endrin had been used on an annual basis for about 10 years and Endrin resistant strains developed. Ten years have now passed since the first resistant strains were found. At this time (1978) Endrin resistance is widespread in the Cumberland-Shenandoah apple region. Therefore, we expect that Endrin will be only a temporary control agent for the margin areas where Endrin has had more limited usage on less than an annual basis. State by state labels for Chlorophacinone baits and ground sprays and Diphacinone baits are now the only cleared alternatives to Endrin. Research on two promising new anticoagulants Brodifacoum and Bromadiolone was reported.

A nationally funded coordinated research program was discussed at a night session. The USDI personnel presented a 1.3 million dollar "add-on" appropriation proposal to their budget designed for both in-house and contract research. This "add on" proposal was approved in early May by the Interior sub-committee. By early June it had passed the full committee on Interior. The House and Senate must yet act on the full Interior Bill, but it is not likely the pine vole research money would be altered after approval by the sub and full committees. In addition soon after the symposium, a tentative National Pine Vole Advisory Council was appointed by a number of State Horticulture Societies. This list of individuals appear to have the knowledge and expertise to assist in the development of a coordinated balanced re¬search program as federal funding becomes available.