Quote:
Originally Posted by FredB
Whiteflies have evolved resistance to pyrethrins, even including most of the newer synthetics.
I get whitefly infestations when I take tomato cuttings and grow them under lights in the winter. That tells me that I must have whiteflies out in the garden, but something must be keeping them under control outdoors. In agricultural areas, I wonder if spraying may be making whitefly problems worse by eliminating their natural predators.
Indoors, I find that what works is a product called Nylar. It's a juvenile hormone mimic, which means it prevents the larvae from growing into adults. It's highly toxic to aquatic insects, so it probably wouldn't be a good choice for use outdoors in places like Florida or Hawaii.
http://sitem.herts.ac.uk/aeru/ppdb/en/Reports/574.htm |
I get the same issue with winters, more proof that there is always time for trials even for us northern folk.