My combat of that dreaded Olive Fruit Fly started with the spinosad attract and kill, Dow GF 120. I found it worked well as long as the fly population was low. When I first started to use it in 2003 it was $79.00/gallon usd. Now it is $210.00/gallon usd. Correctly used, requires weekly spot spray applications. (the attractant dries up). The cost and continued need for use from after the flowers are gone til harvest became too much. And heavy fly population meant lower effectiveness, also. I switched completely to the Surround (kaolin clay) product with very, very good success. I do three or fourth heavy coverage sprays after the flowers are gone. Then "maintenance" spray till harvest. (If it rains or heavy fog). I use the Torula yeast liquibater "Mcphail traps along with the spray. In many situations, the first sprayings is all that is needed.The beauty is this process is organic. AND IT WORKS.