Just a few thoughts-
 
1)      Probably one of the reasons your having a problem spraying them is many
var. live in burrows that are quite deep.
 
The spray isn't reaching them.
I once stopped digging for a nest after I had dug well ovver my head.
(5foot 7inches)
 
2)In your climate in N.Y. the bumbles will not be able to overwinter so
if all else fails the problem will be dealt with in time.
 
3) Now for an idea -
 
Try devising a bee escape one that allows them to go out and not return.
i.e. a ccone of window screen with the entrance squezed flat so that the
bees can push theeir way out of the narrow end but won't be able to return.
 
If this is unclear email me back.
I'll try to think of a better way to describe it.
 
Good luck,
 
John Spaulding          Associate Curator, Wildlife Center
[log in to unmask]        New England Science Center
 
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