Grasshoppers have been a crop pest since the beginning of time and are mentioned in the Bible (The Biblical locusts were a species of Grasshopper)

And the LORD said to Moses, "Stretch out your hand over Egypt so that locusts will swarm over the land and devour everything growing in the fields, everything left by the hail." So Moses stretched out his staff over Egypt, and the LORD made an east wind blow across the land all that day and all that night. By morning the wind had brought the locusts; ...  (Exodus 10;12 - 13)

 

Grasshoppers can be a serious pest in the garden depending primarily on environmental and other factors. The descriptive section for grasshoppers has been omitted from this section, because unless you grew up on Mars you should already know what a grasshopper looks like.

Grasshopper eggs begin hatching in late Spring and early summer. The immature grasshoppers ( nymphs) feed on tender grass and succulent plants in the area where they hatched. As Grasshoppers develop they spread to adjacent areas such as your Garden and feed on an increasingly-diverse variety of plants.

Grasshoppers chew almost any type of leaves, but prefer softer vegetation. They'll favor lettuce, for example, rather than tougher material, such as tree leaves. As far as vegetables go, they prefer lettuce, carrots, and onions. If given a choice, grasshoppers usually avoid squash, peas and tomatoes leaves. (They do, however, like tomato fruit.) Besides planting these vegetables, a good strategy is to plant early-maturing varieties of other crops that you can harvest before mid -to -late August.
 

Grasshopper Bait, No Metaldehyde, No State Restrictions, Also Kills Armyworms, Ants, Crickets, Darling Ground Beetles, Centipedes & Millipedes, Active Ingredient Is Carbaryl

The Praying Mantid is an adored beneficial insect and a general predator of most pest insects including grasshoppers..

Bacillus Thuringiensis Thuricide

is used by organic gardeners to spray plants. This material (containing Bacillus thuringiensis Kurstaki, .8%) is used to kill plant eating caterpillars, moth larvae, Gypsy Moth larvae and other leaf eating Critters

*Plant the herb horehound and or Calendula as deterrents which repels grasshoppers... Learn more about Herbal deterrents

Grasshopper nymphs live for up to 2 months, after which the adults appear and continue feeding until they are killed by cold weather.
While adults are busy reproducing and laying eggs, nymphs have only one focus... To Chow down on your Lawn and Garden. Damage caused by grasshoppers appears as irregular holes at the edges of leaves.

Exceptional populations of grasshoppers occur when weather, predators, parasites and pathogens combine in a way that allows more-than-usual numbers of eggs and nymphs to survive. A wet / cool spring, with temperatures below 65 degrees, results in less eggs hatching. A warm, dry spring will result in more grasshoppers in the fall.

Insecticides for grasshopper control include Sevin , diazinon, malathion and rotenone. Check the label to make sure the crop you intend to spray is listed on the label directions. Apply at only the rate listed on the label and repeat no more often than specified. Check harvest waiting restrictions for the waiting period between application and harvest.