Dry Weather and Grasshoppers
Dr Mario A. Villarino,
County Extension Agent for Agriculture and Natural Resources in Hopkins County.
Recent days without rain had serious effect in the grasshopper population in Hopkins County. Phone calls to the extension office from Brashear and Sulphur Springs relating to grasshopper damage has lead me to believe that young populations are already grown up for several weeks now. When referring to grasshopper control, Dr. Allen Knutson, Extension Entomologist explains: 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. Large numbers of grasshoppers in the late summer can deposit large numbers of eggs which hatch in the spring. Also, rains in the spring when eggs are hatching drown young hoppers and encourage fungal diseases which kill hoppers. Thus, dry weather in the spring favors their survival. During hot, dry summers, weedy hosts dry up and grasshoppers fly in search of green plants. The search for food can result in large numbers of grasshoppers concentrating in orchards, crops and irrigated landscapes. Grasshopper eggs are deposited in the soil ½-2 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 grasshopper 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.. Shallow tillage of the soil in late summer may be of some benefit in discouraging egg lay. 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. Some insecticides for controlling grasshoppers in the home landscape include: Cyfluthrin. The active ingredient in Bayer Advanced Home and Garden Spray and Tempo. Bifenthrin. Active ingredient in Ortho Ready-to-Use Houseplant and Garden Insect Killer Permethrin. Active ingredient in Spectracide and other products. Acephate. Active ingredient in Orthene. Note: Tempo (cyfluthrin) and Demon (cypermethrin) are labeled for use by Professional Pest Control Operators for insect control in lawns and landscapes. 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 vegetable crops. For those wanting to make their own grasshopper bait, the labels for Sevin XLR and Sevin 4-Oil ULV provide directions for mixing these product with cereal grains to make a 2% to 10% carbaryl bait. The bait is labeled for use in rangeland, wasteland, ditch banks and roadsides. The label further states the bait is for use “only by government personnel or persons under their direct supervision (e.g. USDA, state and local extension personnel, etc.).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. Floating row covers can protect vegetables, flower gardens, small fruit trees and other small areas from grasshoppers. These lightweight fabrics let sunlight in while protecting plants from insects and cold. However, under heavy attack, grasshoppers may chew through the fabric to get to plants. For more information on grasshopper control or other agricultural questions please contact the Hopkins County Extension Office at 903-885-3443 or e-mail me at mavillarino@ag.tamu.edu. Professional Ag Workers have selected the recipients of the 2012 scholarships. Four scholarships were awarded in the amount of $500.00 each. The four well deserving people receiving the scholarships are Rebecca George, Ian Zeringue, Jessica Cowley, and Colby Wayne Parker. Letters have been sent informing them about receiving the scholarships. Congratulations to these students for their effort and scholarships!
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