Question: Does a cold
winter suppress wasp numbers?
A: Probably
not. Overwintering queens are fully
adapted to the local climate so even an
unusually cold winter probably does not
significantly increase their mortality. Plus,
even if queen mortality is higher the
surviving queens likely have more success, and
bigger nests (same reason that is discussed
above).
The factor that does suppress
yellowjacket numbers in late summer is spring
weather. Cold,
wet springs tend to interfere with
nest initiation while warm, dry weather
tends to help it along. These effects
can be very localized, however.
Question. Are
poison baits available for area-wide
control of problem nests?
A: Yes!.
A new insecticide called Onslaught
Microencapsulated Insecticide is
now available for bait preparation. See Using
Yellowjacket Baits for details.