The product worked as long as you got it directly on the no-see-ums. (I found out after purchasing this product that it actually suffocates the insect) However, leaving a residue didn't have any affect. This was an expensive purchase for minimal results and the product requires a ton of personal protection equipment. It has a TON of warnings! Consider fly traps at WalMarts for $5.
Large yard on lake and next to canal. Product works great for 3 to 5 days. After that seems to have little effect. Did have some rain. Would start getting bites. Did work better then Talstar P for initial knock down. Used backpack blower/mister for application.