Treesearch

Reference is made to a recent interprovincial review of the performance of present day B.t. viz a viz conventional chemicals. The argument is presented that in the Canadian context its practical acceptability to resource managers remains highly jurisdictionally-specific for reasons over and above conventional technical assessments. The New Brunswick situation is reviewed as a case in point.

Spray operations against the spruce budworm have been conducted in New Brunswick in 1980, 1982 and 1983 and in Nova Scotia from 1980 to 1983. The results obtained in terms of foliage protection have been extremely variable. Attempts to pinpoint the causes for this variable result suggest that a number of factors are responsible. These are weather during and after spraying and sampling problems.

Operational programs to suppress gypsy moth populations in residential and recreational areas first began in New Jersey in May of 1980. Bacillus thuringiensis was used on approximately 17,000 acres applied at the dosage rate of 8 B.I.U.'s in one gallon of water per acre. Two treatments approximately one week apart were applied.

Pennsylvania's first experience with using Bt on insect control occurred in 1964. For the next 17 years, various projects were conducted, in cooperation with the USFS and industry, in an effort to secure operational status of Bt for gypsy moth suppression. This point was reached in 1982, and the Governor was convinced that the time was right to convert most gypsy moth suppression operations from chemical spray to Bt. In 1983, 326,000 acres of high-use areas were treated with Bt, making it the largest Bt operation on the gypsy moth undertaken to date. Suppression results were virtually on a...

The Passamaquoddy Indian Forestry Department treated 40,300 acres in Maine in 1983 using Bt to protect red spruce and eastern hemlock from spruce budworm damage. The post treatment evaluation indicated that the protection objectives were achieved. In cooperation between the Passamaquoddy Indian Forestry Department and two commercial Bt suppliers, Abbott Laboratories and Zoecon Corporation, four commercial products were applied as eight field formulations. Where possible, these treatments were compared for effectiveness. The results show an average defoliation of 23 percent and population...