Excellent coverage is a must. For plum curculio, the first application should be made right at Petal Fall, with a follow-up application no more than a week later. It takes two applications to establish the level of residue and coverage required for full efficacy. Continued protection through the plum curculio immigration period would require reapplication at 7-10 day intervals. Because the Surround doesn't kill the plum curculio that encounter it, protection might be required for a longer period than the 3 to 5 week protection period required with organophosphate insecticide.
Kaolin clay is sold in bulk form for many uses such as papermaking and pottery.
Therefore, one might be inclined to think it is possible to save some money by purchasing cheaper bulk kaolin clay instead of paying for the same material labeled as Surround. However, the kaolin clay in Surround and the kaolin clay sold for other uses are really different materials using the same name. These attributes are essential to the way Surround functions. The finished product is hydrophilic instead of hydrophobic, and the mean particle size of Surround is much smaller than bulk kaolin clay, and just as importantly, the range of particle sizes is narrowed. Particle size makes all the difference in how the particles affect insects.