I recently posted this information on another thread:
"Preventing Problems: Keep grassy weeds controlled, as they are grasshoppers’ preferred host plants. Encourage predation by wild birds and domestic poultry. Provide a moist, grassy spot far from the garden as alternative habitat. In areas where grasshoppers are a major pest, inoculating the soil with Nosema locustae will help limit populations.
Managing Outbreaks: Cover susceptible plants with row cover (garden fleece) or cones or covers made from window screening. Allow chickens to forage in the garden for a short period before dark.
Tips: Guinea hens are considered the ultimate control for grasshopper-plagued gardens."
http://bigbughunt.com/bug-guides/us-and-canada/grasshopper/