By Dr. Vanessa Corriher-Olson
Texas A&M AgriLife Extension Forage Specialist
There are about 150 species of grasshoppers in the state of Texas, but 90% of the damage to crops, gardens, trees and pastures is caused by just 5 species.
Grasshoppers deposit their eggs one-half to two inches below the soil surface in pod-like structures. Each egg pod consists of 20 to 120 eggs. Egg pods are very resistant to cold and can easily survive the winter if the soil is not disturbed. Grasshoppers deposit eggs in fallow fields, ditches, fencerows and weedy areas, as well as in crop fields and hay fields.
Eggs begin hatching in late April or early May; hatching peaks about mid-June. If spring weather is cool and dry, hatching may be delayed until July. Young grasshoppers are called nymphs. They look like adults but are smaller and do not have wings. Nymphs go through five to six developmental stages and become adults in 40 to 60 days, depending on weather and food supplies.
The adult grasshoppers deposit eggs from late July through the fall. Usually only one generation of grasshoppers is produced each year.
Producers should start watching for grasshoppers early in the season and begin control measures while grasshoppers are still nymphs. Smaller grasshoppers are more susceptible to insecticides than larger ones.
Cultural Control: Controlling summer weeds reduces available feed for newly hatching nymphs as well as making it easier for birds to prey on grasshoppers.
Chemical Control: Grasshoppers are susceptible to many insecticides. The length of control will depend on the residual activity of the insecticides and the frequency of treatment. Controlling grasshoppers over a large area will reduce the numbers present which can re-infest a treated area. Remember, smaller grasshoppers are more susceptible to insecticides than larger ones.
Always read and follow all label instructions on pesticides! Insecticides that can be used on pastures and hayfields:
•Mustang Max (9.6% zeta-cypermethrin)
•Karate Z (lambda cyhalothrin): Do not harvest for hay until seven days after application
•Baythroid XL (beta-cyfluthrin)
•Dimilin 2L: Dimilin must be applied when grasshoppers are about a quarter-inch. Dimilin is not effective on adults. (Generics are now available.)
•Sevin 4F, Sevin XLR, Sevin 80S, generic Carbaryl: 14-day waiting period before grazing or harvesting
•Tombstone Helios (cyfluthrin)
•Multiple products (examples include Lambda-Cy, Grizzly Z, Kendo, etc.; lambda-cyhalothrin)
•Vantacor (chlorantraniliprole): For optimum control, apply to nymphs.
•Besiege (chlorantraniliprole + lambda-cyhalothrin): labeled for grasshoppers and armyworms.