Hi Mathew and Everyone,

I just have to comment on this one.

Mathew wrote in part:

"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."

Sorry Mathew but Btk only kills leps in the first and second larval instars.  Anyone who has used in their garden has notices this if they carefully watched.  It is very effective on the small larvae but does not seem to touch the larger ones.  One or two gypsy moth sprays in an area about one week apart timed by oak leaf emergence pretty closely targets gypsy moth and here does not hit the forest tent capillar with is ahead of the gypsy moth.  It will also have no effect on leps that are more than a week or so later in hatching due to its being washed off the vegation and degraded by sunlight.  I agree it is to be used carefully but how much more closely can you target a treatment?  And also remember with gypsy moth there is likely going to be more applications of other less targeted insecticides if the Btk is not used.  On balance it appears to be the best option for dealing with this situation.  Not perfect but the best available.
It will not produce a "butterfly free zone".

blane


******************************************
Blane White
MN Dept of Agriculture
[log in to unmask]