If you use liquid Sevin and spray in the evening when bees are back in their nests there is little risk to bees. If you use Sevin powder and spread it during the daytime when bees are active, you are possibly going to poison some bees and they may carry dust back to the nest where it will poison more bees. Sevin powder rates a 1 on the the health rating scale:
A cash crop is an agricultural crop which is grown for sale to return a profit. It is typically purchased by parties separate from a farm. The term is used to differentiate marketed crops from subsistence crops, which are those fed to the producer's own livestock or grown as food for the producer's family.
The majority of corn is used for animal feed, ethanol, starch products (used not just in food processing, but in manufacturing fuel filters, batteries, baby powder, sanitary napkins, and much more...), and sweetener. A 'cash crop' is something which is grown for the generation of capital. A 'non-cash crop' or 'subsistence crop' is grown for direct consumption by the producer, their family, or their livestock. The term 'food crop' is much more ambiguous, and cannot necessarily be differentiated from a 'cash crop'. Many 'food crops' (tomatoes, potatoes, asparagus, apples...) can actually be 'cash crops' if they are produced specifically for the generation of income through sale. Items that are highly perishable and difficult to process or ship tend to be used much more often as 'food crops' than 'cash crops'.