Grasshoppers

As summer heats up the extension office is receiving a growing number of inquiries about grasshoppers and the damage they are doing to gardens and agriculture. Infestations are spotty around the county but if you are in an area where a population explosion is occurring damage can be considerable. Here is some basic information and some web site links with more detailed information. The following information is from http://attra.ncat.org/attra-pub/PDF/grasshopper.pdf

Life Cycle
There are three stages in a grasshopper's life cycle, the egg, nymph (the young grasshopper), and the adult. Most grasshopper species over-winter as eggs, which are laid in clusters in late summer and early fall and hatch in spring, when soil temperatures warm up.

It takes approximately 40 to 60 days for the nymph to fully develop into an adult. During this time, it sheds its exoskeleton several times as it moves from one nymph stage—called an instar—to another. The best time to control the insect pest is during early nymphal development, when it is most vulnerable to disease, parasites, predators, insecticides, and inopportune weather. Adult grasshoppers are virtually impossible to control, hence preventive management is of the essence.

Although grasshoppers are difficult to control, their impact can be minimized by preventive management over the long term.

Weather
Grasshopper outbreaks are determined by a complex interaction of several factors, of which weather is the most important. Warm and dry spring conditions encourage nymphal growth. An early spring followed by cloudy, damp weather encourages diseases that sicken and kill hoppers. A long, hot summer ensures a plentiful food supply and encourages early maturity of grasshoppers and a long egg-laying period. On the other hand, a cool summer and early fall slows down grasshopper maturity and reduces time for laying eggs.

Predators
Natural predators and parasites rank next in importance to weather in keeping grasshopper populations in check. In addition to Integrated Pest Management programs that reduce pesticide usage, actions that increase the numbers of beneficial insects and other organisms in the agro-ecosystem must be encouraged. For additional information, see ATTRA's publications Farmscaping to Enhance Biological Control and Biointensive Integrated Pest Management. Crop rotation and other organic practices that increase bio-diversity offer a certain degree of protection against pests. Grasshoppers are drawn to monocultures and dislike nitrogen-fixing crops like peas and sweet clover. Rotation, cover cropping, and other practices that promote bio-diversity make farm habitats more attractive to the host of natural predators and parasites that control localized grasshopper infestations.

Domesticated poultry like chickens, turkeys, guinea fowl, geese, and ducks are good for keeping grasshopper populations in check, although they tend to damage the plants in the garden too. One way to handle this is to confine the birds to the greenbelt. Another is to enclose them in wire fencing along the perimeter so that they can prey on visiting grasshoppers while staying out of the crop.

For more information on grasshoppers and their control visit:

Grasshopper Control in Gardens and Landscapes

Grasshopper Control in Yards and Gardens

Grasshoppers in Washington