Just about anything that will kill a Colorado potato beetle will kill bees. Fortunately CPB's rarely attack anything other than potatoes and eggplants. Carbaryl is a contact insecticide, you have to hit them to kill them. When used in the late afternoon ( spray) when bees are not working, it will safe for them in morning when they return to work. Avoid the dust, as it is water activated and will hang around until wetted. Like all pesticides, safety depends on KNOWING what you are doing. They are not preventatives but to be used against an invasion.
Wilson Sweet is good ( better than Sugar Baby in my opinion). You are pretty late with them, but should have plenty of time) First set may be two or three melons per vine. They are competitive and will compete for space. They will fare better than their neighbors. All watermelons hate clay soil so that may be a problem. They don't need a lot of fertility. They grow wild in fence rows for example.
Watermelon (Citrullus lanatus 'Wilson Sweet')