South Dakota has recently experienced an increase in the proportion of acres treated with insecticides. As pest control measures have changed with the adoption of genetically modified seed and increased specialization of agriculture production has resulted in crop producers having increased reliance on technical specialists and crop specialists. The following case studies seek to explore the reasons for the increase as well as analyze crops treated by Commercial Applicators. The following two case studies take different approaches to examine insecticide usage in South Dakota, one evaluating the proportion of acres treated over the past thirty years and the other looking at pounds of insecticide applied by Commercial Applicator’s in 2002. The studies provide insight on the cause of the increase in the proportion of acres treated with insecticides and how the crops are being treated by the Commercial Applicator and the specific chemicals being applied.