According to Pest Control Options, effective strategies for getting rid of grasshoppers include keeping insect-eating animals on the property and dusting plants with flour. Ducks, chickens, guinea pigs and turkeys eat grasshoppers and are useful additions to any grasshopper reduction plan. Another effective measure is dusting plants with unsalted plain flour. Grasshoppers that eat flour-dusted plants soon find their mouths clogged with sticky flour.
According to the Colorado State University Extension, grasshoppers are the most bothersome and tenacious of all garden pests because of their prodigious leaping ability. Grasshoppers lay tiny egg clusters in the soil that are difficult to spot before they hatch. Effective strategies for killing grasshopper eggs include chemical pesticides and poisoned grasshopper bait.
Pesticides are only effective when sprayed over the entire property. The Colorado State University Extension recommends applying pesticides in May or June and adding canola oil to the mixture. The oil attracts grasshoppers and encourages them to consume pesticide-treated leaves.
The most popular biological grasshopper bait contains Nosema locustae, a protozoan that causes infections in young grasshoppers. Nosema locustae only harms grasshoppers and has no adverse effects on ladybugs and other beneficial garden insects. The bait works slowly, however, and is ineffective on older adult grasshoppers. Packages of Nosema locustae bait require refrigeration and remain effective only until their expiration date.