How to get rid of grasshoppers
The control for grasshoppers is a tricky one. Like the Japanese beetle, it’s better to attempt control at the egg-laying season or the early hatching season. Once the adults begin to invade your space it gets a lot harder.
There is a bait made from the spores of a protozoan Nosema locustae sold under the name of NOLO Bait or Semaspore that is effective in controlling young grasshoppers. Once the hoppers mature, its effectiveness diminishes.
Some non-chemical alternatives would be: the use of row covers, leaving border areas of tall grass where the grasshopper will feed instead of your garden and/or adding several praying mantises to your garden. Poultry, snakes and toads think they’re a good dinner, as do robber flies, spiders and blister beetles. These methods all have a lot of limitations. Some other organic options have been often suggested, such as planting the herb horehound as a repellent, or cilantro or calendula as a barrier crop. Diatomaceous earth can also be used and will remain effective until it is washed away by rain or watering. Be sure to use the appropriate precautions when applying it as it can be an irritant if inhaled. Also on the list of possible sprays is Neem Oil, but again its best use is on the younger hoppers. You could also try one of the HOT Pepper sprays.
For a chemical alternative the best time to control with insecticides is when the grasshoppers are between 1/2 and 3/4 inch long, generally mid- to late June, depending on your area. Most of the eggs have hatched by this time and the younger grasshoppers are more susceptible to the toxins. Spraying later might not be as effective, as the larger hoppers have laid their eggs and moved on or may be in adjacent undeveloped land that you cannot treat. The common insecticides listed for yard and garden use include; carbaryl, acephate, and permethrin. These are found under several popular brands and you should read and follow the instructions carefully. Remember: these are non-selective killers and can wipe out good guys, too.
It’s difficult to tell what will work best and there are a number of “homemade” remedies out there if you do a little search online–but, there are no guarantees and sometimes they can be harmful if not mixed correctly.
You might also hire a number of small children to run about your yard every day and collect or scare them away. Of course, this will cost you lots of cookies and Kool-aid!