what is the difference between talstar and suspend?

Both the Suspend SC and the Talstar P contain synthetic pyrethroids for active ingredients and will provide very similar results. The only advantage to using Talstar P over Suspend SC is that it is known to be super gentle on most plants (do not use on edible vegetation) and is virtually odorless while Suspend Sc does have a slight odor. Both products can be used indoors and outdoors and both products are safe to use in houses with children and pets.
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It is good practice to alternate between the 2 to avoid some pests from building a resistance to one or the other. I used Talstar for the first time early this summer and it has worked great. I'll use Suspend in the fall.