By Dennis Smith
Consecutive years of hot, dry summers and warm, dry autumns favor grasshopper survival and reproduction. Warm, dry fall weather allows grasshoppers more time to feed and lay eggs.
Spring rains will drown young hoppers when eggs are hatching. Thus, dry weather in the spring favors their survival. Grasshopper eggs are deposited in the soil l/2 – 2 inches deep in weedy areas, fence rows, ditches and hay fields. The eggs hatch in the spring and early summer. Eggs of different grasshopper species hatch out at different times, so young grasshoppers can be seen throughout the spring and early summer. Young grasshoppers, called nymphs, feed for about six weeks. Once nymphs reach the adult stage, they can fly. As weedy plants are consumed or dry in the summer heat, adult grasshoppers can fly from weedy areas and pastures to more succulent crops and landscapes.
Although grasshoppers complete only one generation a year, eggs hatch over a long period of time. Development from egg to adult requires about 40-60 days. Also, eggs of different species hatch at different times so small grasshoppers can be found throughout the growing season. Grasshopper can persist until late fall when old adults begin to die or when a killing frost occurs.
Eliminating weeds will starve young hoppers and later discourage adults from laying eggs in the area. Destroying weeds infested with large numbers of grasshoppers can force the hungry grasshoppers to move to nearby crops or landscapes. Control the grasshoppers in the weedy area first with insecticides or be ready to protect nearby crops if they become infested. Grasshoppers deposit their eggs in undisturbed soil, as in fallow fields, road banks, and fence rows.
Grasshoppers are susceptible to many insecticides. However, insecticides typically do not persist more than a few days and grasshoppers may soon re-invade the treated area. The length of control will depend on the residual activity of the insecticides and the frequency of retreatment. Controlling grasshoppers over a large area will reduce the numbers present which can re-infest a treated area. Dimilin 2L provides long residual of young hoppers but is not effective against adults.
Monitor grasshopper infestations and treat threatening infestations while grasshoppers are still small and before they move into crops and landscapes. Immature grasshoppers (without wings) are more susceptible to insecticides than adults.
Sevin 5 Bait is a ready-to-use bait which can be applied to many crop and non-crop sites, including around ornamentals and many fruit and vegetables.
The biological control products contain spores of a protozoan called Nosema locustae, formulated in a bait. Grasshoppers consuming the bait become infected by the Nosema organism. Some immature grasshoppers die while adults often survive but females lay fewer eggs. Nosema baits act too slowly and kill too few grasshoppers to be much value when the need for control is immediate.
Some insecticides for controlling grasshoppers in the home landscape include: Cyfluthrin, Bifenthrin, Permethrin and Acephate. Always read and follow all label instruction on pesticides.
Products labeled for grasshopper, control in pastures and hay meadows include Malathion, Mustang Max, Sevin, Dimilin and Karate. Producers using these products are reminded to follow all label instructions. These products vary on the number of days required from application to harvest or grazing.
Find additional information on grasshopper control on the Texas AgriLife Extension Service web page at gregg-tx.tamu.edu/
References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas AgriLife Extension Service is implied.
Dennis Smith can be contacted at the Gregg County Extension Office by e-mail at firstname.lastname@example.org or telephone at: 903-236-8429.
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