>>The report from the SF Bay Area here...
 
>Could it be the spraying of malathion has finally taken its toll? Did they
>spray for the med fly again?
>
>In way of review: the powers that be sprayed parts of the bay area from the
>air. Everything was sprayed with malathion. All for a fruit fly...
>
>Chris
 
 
  Insects regularly go through cycles, classic examples often brought up
via the media include the Gypsy Moth and its build up and collapse.  Here
in NY I have observed up and down years for everything from butterflies to
polistes.
  This past winter was definitely a bit on the extreme but one probably
cannot conclude that this was the sole cause for population collapse of
polistes pops here but may have been a contributing factor.  I bet they
will be back in a few years since mans dwellings have artificially
increased their habitat by providing excellent protective shelter both
during the active and inactive periods of their life cycles.
  Guess in areas that were heavily sprayed with Malathion one could not
discount this as a possible cause for a population crash but yearly cycles
should bring the numbers back up.  OMHO Mike