(a) Btk: Due to proprietary information exemptions in the Access to Information Act, Agriculture and Agri-Food Canada (AAFC) cannot disclose the total contents of Foray 48B, the particular formula of Btk used for the eradication of gypsy moths. What we can say is that the active ingredient is a bacterial insect disease, Bacillus thuringiensis Kurstaki-Btk. Small amounts of chemicals are used in the commercial fermentation process, and the bacteria metabolize these into complex and simple sugars and water in the final formulation. The final formulation has been examined by Health Canada and Environment Canada and has been proven safe; it is even certified for use by organic growers.
(b) Treatment Effectiveness: European gypsy moths (also knows as North American gypsy moths) have been accidentally moved to British Columbia on household effects numerous times in the last 17 years from infested areas of eastern North America and elsewhere. Thirty-nine male moths wer caught in pheromone-baited sticky traps in B.C. in 1994 and again in 1995; prior years moths trapped have numbered over 200 males. (The pheromone is a sexual lure used to attract male gypsy moths only.) When gypsy moths are trapped at low density (one or two in a trap with no moths in surrounding traps), the figures do not necessarily indicate a sustainable population and therefore eradication is not necessary. However, the area surrounding such finds is always closely monitored for two subsequent years to determine whether the population is increasing or has failed to develop.
British Columbia is uniquely placed in that it has the pressure of introductions of North American gypsy moths by land and air from eastern North America and of Asian gypsy moths by sea and air from countries to the west. The Asian gypsy moth threatens its habitat far more than the European gypsy moth, being a more aggressive feeder, feeding on a wider host range, and having females capable of flying before they deposit their prolific egg masses. It was multiple catches of the Asian gypsy moth on the Vancouver waterfront that launched the intensive spray program in 1992. Asian and North American gypsy moths are capable of cross-breeding, the result of which is a North American gypsy moth with females capable of flying. Prior to determining a treatment response, it is thus essential to determine whether the gypsy moth is of the Asian, European, or hybrid genotype; this is done through genetic fingerprinting.
The following shows the number of male gypsy moths trapped before and after spraying during the last 10 years in the greater Vancouver regional district.
Vancouver waterfront (includes areas of North Vancouver, West Vancouver, Burnaby):
-1988-1 male was trapped1; -1989-6 male gypsy moths were trapped2; -1990-10 male gypsy moths were trapped3; -1991-33 male gypsy moths were trapped inside the spray zone (27 Asian gypsy moths introduced from Russian freighters in Vancouver Harbour)4; -1992-area was treated with Btk for Asian gypsy moth; following treatment 2 male gypsy moths were trapped, one just outside the treatment zone; -1993-0 male gypsy moths were trapped;
Burnaby
-1992-9 male gypsy moths were trapped (3 of these were outside the treatment zone); -1993-area was treated with Btk; following treatment no male gypsy moths were trapped in treatment area;
Richmond
-1991-3 male gypsy moths were trapped (just outside what later became a treatment zone); -1992-61 male gypsy moths were trapped; -1993-area was treated with Btk; following treatment 2 male gypsy moths were trapped outside the treatment block; -1994-0 male gypsy moths were trapped; -1995-1 male gypsy moth was trapped5;
1 Singleton moth not requiring immediate treatment.
2 Singleton moths not requiring immediate treatment.
3 Singleton moths not requiring immediate treament.
4 Information pertaining strictly to treatment zones was forwarded to MP's Ottawa office as a result of a request to Gypsy Moth Information Line.
5 Singleton moth not requiring immediate treatment.
South Vancouver
-1991-1 male gypsy moth was trapped6; -1992-5 male gypsy moths were trapped (1 just outside what later became a treatment zone); -1993-20 male gypsy moths were trapped; -1994-area was treated with Btk; following treatment no male gypsy moths were trapped in treatment area;
New Westminster (Sapperton)
-1993-1 male gypsy moth was trapped7; -1994-1 male gypsy moth was trapped; -1995-8 males gypsy moths were trapped in what is the proposed treatment zone;
New Westminster (other than Sapperton)
-1995-4 male gypsy moths were trapped8.
(c) Notification/Education:
(i) Gypsy Moth Open House public information session on February 15, 1996 in New Westminster; (ii) mailout to residences in treatment blocks; (iii) newspaper advertising of pesticide use permit application; (iv) newspaper and television education and interviews; (v) door-to-door contact with homeowners during egg-mass searching; (vi) resource materials in local libraries; (vii) information letters to the school in the New Westminster treatment block; (viii) frequently-asked question list sent to the newspaper (this list was not published): (ix) telephone 666-MOTH line to answer questions on a one-to-one basis; (x) presentations to city Councils in treatment blocks; (xi) consultation with local medical health officers; (xii) detailed information sent to B.C. Environmental Appeal Board in response to appeals against AFFC's pesticide use permit.
(d) Alternative Treatment Information: An aerial application of a chemical insecticide is the most cost-effective and efficacious method of eliminating gypsy moths. However, these chemicals tend to affect a wide range of non-target organisms and to raise public concerns about human health. While AAFC chooses not to use these alternatives and therefore does not know the cost-effectiveness ratio for such a treatment, it can be deduced that the treatment would be cheaper because chemical insecticides are cheaper than bacterial insecticides and only one spraying is needed to eradicate the moths.
Mass pheromone trapping is a non-viable alternative for eradiction because of the fact that it is not a legal option in Canada. It is an experimental approach of using huge numbers of traps to interfere with mating: 5,000 traps per square mile are set out two years running at a current cost of around $100,000/square mile.
For the eradication of the gypsy moth population indicated in Sapperton, the British Columbia Regional Office of Food Production and Inspection Branch of AAFC has chosen to use an efficacious ground-spraying program of Btk to take into consideration public discomfort with the aerial application of a pesticide. This year, the cost-effectiveness ratio of a ground application compared with an aerial application of Btk is 8:1, though this varies with the size of the areas.
6 Singleton moth not requiring immediate treatment.
7 Singleton moth not requiring immediate treatment.
8 Moths not requiring immediate treatment.