Chuck,

There is apparently no impact on bees from spraying Btk. Different variants of Bt will effectively target different orders of insects: Btk will only hit Lepidoptera. Of course, Lepidoptera is one of the more diverse orders of insects (approximately 13,700 species in North America) and Btk will kill most species of moths and butterflies in addition to the targeted gypsy moth.

Btk is widely used under the guise of being a benign or less damaging treatment than the chemicals previously used. It is (remember Fenitrothion spraying in New Brunswick to control spruce budworm?), but we should still be concerned about the widespread use of an insecticide that wipes out an order of insects. Imagine a dead zone for butterflies, especially if you are correct about Chicago being targeted.

The second issue is related to you using Bt in your backyard. Bt is a valuable tool of gardeners and organic growers and primarily used for spot treatments. Large-scale, widespread and repeated use will likely lead to resistance in pest species to it and it will be no longer of any use. There are reports or diamond back moths developing resistance to Bt in the Northeast, and it may be just a matter of time until resistance develops in other species. This is well recognized in relation to genetically modified crops that have Bt inserted. There is a requirement for farmers to grow a percentage of non-GM crops to reduce the chances of this happening in corn borers and similar. If Bt becomes useless, what do we replace it with?

We have been opposing (unfortunately, unsuccessfully) aerial Btk spraying here in Portland, Oregon, but there is a fair amount of information about Btk on our website (www.xerces.org) under "What we do." You'll also find a lot of information on native bees, and our work to conserve native pollinators.

Matthew Shepherd
The Xerces Society, Portland, OR

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On 5/16/01 at 12:33 PM Chuck wrote:

>The newspaper says that gypsy moth spraying using
>bacillus thurengiensis kurstaki (BTK) will begin
>20 or so miles from my area (Wheaton & Wayne, IL).
>I had previously heard that the whole Chicago area
>would be sprayed for gypsy moth this summer.



_____________________________________________________________
Matthew Shepherd
Director, Pollinator Program and Publications

The Xerces Society
4828 SE Hawthorne Blvd, Portland, OR 97215
Tel: 503-232 6639   Fax: 503-233 6794
Email: [log in to unmask]
_____________________________________________________________
The Xerces Society is an international nonprofit organization
dedicated to protecting biological diversity through the
conservation of invertebrates.
For information and membership details, see our website:
http://www.xerces.org/
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