According to the package, sevin is an effective control if
applied more than 7 days apart and no more than 6 times per crop.



I have tried Sevin, Its life spna is too short to be effective, It is also
deadly to bees, so you have use a spray late in the evening. The extension
services recommendation is Thiodan but it is also very toxic to bees and I
would not recommend it especially on a cucumber.