Type grasshoppers in the search box in upper left of most pages and find what's already been written here about them. Here's a link to one of the earlier threads:
Here's a reference re organic control of grasshoppers:
Predators include snakes, toads, cats, mice, a number of birds (bluebirds, sparrows, mockingbirds and others), chickens, ducks, geese, spiders, horsehair nematodes.
Barriers: grasshoppers are said to be repelled by horehound, cilantro, calendula, garlic oil, and nitrogen-fixing crops like peas and sweet clover.
Row covers, like Reemay, or screens can be effectively used to keep them from your crops.
Garlic Oil Spray
To make: Combine 3 ounces of minced garlic cloves with 1 ounce of mineral oil. Let soak for 24 hours or longer. Strain.
Next mix 1 teaspoon of fish emulsion with 16 ounces of water. Add 1 tablespoon of castile soap to this.
Now slowly combine the fish emulsion water with the garlic oil. Kept in a sealed glass container this mixture will stay viable for several months. To use: Mix 2 tablespoons of garlic oil with 1 pint of water and spray.