wasp problems

[Appliquer]

I can understand your wanting to protect the butterflies, but aren't the
parasitic wasps also a part of nature.  Wouldn't allowing them to hatch also be
facinating to the children (things don't always turn out the way we are led to
expect)?  Is the butterfly garden enclosed, if not just sparying will not
prevent new wasps from arriving to parasitize new caterpillars.  How do you
know that the pillars you remove for the sparying are not already parasitized?