Spray trial in the Cape Breton Highlands--Op-Ed Piece

By Eric Georgeson, provincial entomologist with the Department of Natural Resources.

The Department of Natural Resources is conducting the spray trial component of its research work with the Canadian Forest Service against the blackheaded budworm. The budworm is threatening about 114,000 hectares of the Cape Breton Highlands.

The spray trial will involve a maximum of 5,000 hectares and only use Bacillus thuringiensis kurstaki (Btk).

There have been recent questions in the media about "inert" ingredients in Btk. The complete formulation for the compound (active ingredient and inert) is tested as a whole. All ingredients are known to Health Canada and the federal Pest Management Regulatory Agency before they make their assessment and review. Health Canada lists Btk as a natural biological control with no impact on humans or animals.

Btk does not affect humans, wildlife or fish, as none of these organisms have the alkaline gut conditions to activate the Btk.

Nor does Btk kill other types of insects such as honeybees, beetles, or flies; only the feeding larvae of moths and butterflies in the treatment area. Most important of all, it does not kill the natural predators and parasites that attack the target population.

Some recent articles have made inaccurate claims about the inert ingredients. Any lists produced by non-scientific organizations and unqualified individuals, are merely conjecture and not based on facts. Health Canada and the company which produces the product are the only credible sources of information about the product, its ingredients and its effects.

One article indicates that Btk can be found in the soil for years after a spray operation. Btk is a natural bacterium, always present in the soil regardless of spraying. Another statement that Btk can be "detected in the air for up to 17 days" after a spray is false. This is impossible as the spray degrades after three to five days.

Similarly, the statement about Btk aerosol being found up to 80 kilometres from the spray site due to drifting on the air is also incorrect. The accuracy of modern technology is impressive; the aircraft flies very low and the spray is deployed only when weather and wind conditions permit. All guidelines from federal and provincial government departments concerning setbacks and conditions of spray application, such as weather and wind, are followed exactly to ensure the product is applied only where it is supposed to go.

All insect outbreaks will ultimately collapse, but when and at what cost? The Eastern spruce budworm outbreak in Cape Breton didn't collapse until more than 70 per cent of the merchantable spruce and fir trees were lost, which cost about $37 million to replace. The result of the damage to the forest was mirrored in damage to the economic and social structures of Cape Breton Island.

All forestry-related employment in the area of the Cape Breton Highlands was adversely affected, and Nova Scotia's taxpayers and industry had to carry the cost of regenerating the Highlands forest. Yet, the loss to Cape Breton cannot be measured in dollars alone. Residents who depended on forestry for part or all of their livelihoods were left to seek other opportunities, often in other parts of the province.

The cost to register Btk as a tool we can use against the blackheaded budworm is small compared to the losses that can be experienced by Cape Bretoners from another major insect infestation in the Highlands.

Spraying is a last resort, used only when all other forest-management options are not found to be effective.

The spray trial is only one of several research components that the province is working on with the Canadian Forest Service. On our behalf, the Canadian Forest Service is also studying the natural predators and diseases of the blackheaded budworm and the impact of the defoliation on forest stands. The federal agency is also developing a monitoring tool for use as an early warning system.

This research, together with the data resulting from the spray trial, will be used to develop forest-management tools for the future. We are not trying to exterminate the budworm. It is a part of the ecosystem of the Highlands forest, and we recognize that it can form a valuable link in the system's food chain and ecosystem. We are trying only to control its population explosion.

It is important that any debate on the use of aerial spraying be based on sound scientific evidence and not on unfounded and unsupported conjecture.

To do otherwise benefits no one and serves only to endanger the livelihoods of those who depend, directly and indirectly, on a healthy and sustainable forest.