Insecticides will kill them, but new ones migrate in, eat the dead grasshoppers, then proceed to eat our plants. Because the bodies of the dead grasshoppers are eaten, it appears that the insecticide failed. Since new grasshoppers have migrated into the area, our gardens are still eaten. Application of appropriate pesticides to barrier plants around our properties can sometimes reduce the problem by killing many of the grasshoppers before they reach our vegetable and flower gardens. However, some will make it through to the gardens and require treatment there with insecticides or hand picking.
Some gardeners raise guinea fowl, turkeys, or other grasshopper eaters.
These can then provide considerable protection from grasshopper damage, even though the fowl will do some damage to fruits and vegetables in the garden. If fowl are used, be sure to select insecticides carefully or, if you prefer, rely entirely on the fowl. Some gardeners use Nosema locustae, a biological control agent for grasshopper control. Products with the Nosema are slow acting and relatively ineffective in controlling grasshoppers once they get larger. Besides, of the many different types of grasshoppers which infest New Mexico, the Nosema is effective with only a few.