[log in to unmask] wrote:

>Could it be that in the south there are more days of flying weather and crops
>to fly to?
>
>
One thing I learned about tracheal and its lack of effect during warm
weather is that pollen seems to be a mite propagation suppressor. So
once pollen starts the mites seem to have little effect.

Also, most of what I have read shows a direct correlation between
crowding, mites and the eventual spread of disease. Since both of the
two former are the typical conditions of a long, cold winter, it means
that we in the North are more likely to have tracheal mites cause winter
problems than the South.

Bill Truesdell
Bath, Maine