The old adage "an ounce of prevention is worth a pound of cure" is good advice when dealing with various gardening issues. This time of year, large grasshoppers are appearing around yards and gardens. Many gardeners saw small grasshoppers several weeks back, and if not treated, they now have large grasshoppers.
It is likely there will be a certain number of grasshoppers in our gardens each year, no matter what treatments are used. Just because grasshoppers are there, they may not need to be controlled, especially if the damage is minor. It is best not to use pesticides unless they are absolutely necessary.
Since grasshoppers are highly mobile, successful management is at its best when grasshoppers are treated over a broad area. In residential areas, this means that several neighbors may need to team up if the problem is serious.
There are several control methods for grasshoppers. Since most lay eggs in the soil in early fall, cultivating garden soil in late fall or early spring may reduce numbers. Additionally, grasshoppers are easier to kill when they are less than half grown. Baits and sprays available through local retailers can be very successful. A popular type contains the grasshopper disease-causing organism, Nozema locustae.
When properly applied and with the correct weather conditions, 50 to 70 percent of grasshoppers can be killed, and many of those remaining are infected and their feeding and egg-laying will be reduced. Local retailers may carry bait containing carbaryl that is also very effective.
Additionally, while the grasshoppers are still small and young, many garden crops are not ready to harvest. If crops are sprayed with an insecticide such as permethrin and carbaryl, there is usually sufficient time so that crops can be fully harvested later on.
For those who missed early treatment, reducing grasshopper numbers later in the season can be more difficult. Most sprays have a minimum five-to-seven-day wait before crops can be harvested and eaten. At this point, gardeners may have to accept the damage and do their best to reduce numbers early in the season next year.
For more information about controlling grasshoppers, see the USU Extension fact sheet, Grasshoppers, at http://extension.usu.edu/files/publications/factsheet/grasshoppers08.pdf.Â