Identify Noxious Pests
To help with our mission to manage invasive species and help Keep Wyoming Wild and Beautiful, learn more about state designated noxious pests. Contact your local District for assistance.
Grasshopper
Grasshoppers have the potential to cause significant harm to Wyoming’s rangeland and crops due to their voracious feeding habits. During outbreak years, adult grasshopper densities can exceed 30 insects per square yard, well beyond sustainable levels in most areas of the state.
Weed and Pest Control Districts also work with USDA APHIS to monitor local and state-wide grasshopper outbreaks.
Get more information:
USDA: Grasshopper Integrated Pest Management User Handbook
University of Wyoming: Grasshoppers of Wyoming and the West
Colorado State University Extension: Grasshoppers in Field Crops
Mountain Pine Beetle
Although there are several native bark beetle species found in Wyoming, the Mountain Pine Beetle is the most widely recognized for its impact. The beetles kill pine trees through larval feeding and by introducing blue stain fungus into the sapwood. In 2011, aerial surveys estimated that over 3.3 million acres of federally managed forests in Wyoming were affected by the Mountain pine beetle.
Get more information:
USDA: Forest Insect and Disease Conditions in the Rocky Mountain Region
Beet Leafhopper
The beet leafhopper, Circulifer tenellus, is the vector of curly top virus. The virus causes curling of beet leaves which later become brittle. This virus has the potential to cause severe economic losses when sugar beets are infected in epidemic proportions. The beet leafhopper overwinters as an adult in rangeland and idle agricultural lands and migrates in the summer to susceptible crops. Treating surrounding non-crop areas and utilizing insecticide-treated sugar beet seeds can assist with managing the virus. Weed and Pest Control Districts may assist local landowners with Integrated Pest Management (IPM) practices to help them minimize the impacts of the beet leafhopper and curly top virus.
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Mormon Cricket
The Mormon cricket, Anabrus simplex, is a large migrating insect in the katydid family (not a true cricket). During mass migrations, Mormon crickets can cause extensive damage to forage plants in crops and rangeland in their migration path. Mormon crickets feed voraciously on wheat, barley, alfalfa, sweetclover, truck crops, and garden vegetables. Because of their migratory habit, a single Mormon cricket spends only three or four days at a particular site, causing little damage in that short time. But migrating bands of nymphs or adults may completely destroy fields of sugar beets, small grains, and alfalfa. During the 1937 outbreak, Mormon crickets caused $383,000 of crop damage in Wyoming.
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Prairie Dog
Prairie dogs are burrowing rodents that can be found throughout the vast rangelands of Wyoming. Of the five species of prairie dogs, two species are known to exist in the state, the black-tailed prairie dog, Cynomys ludovicianus, and the white-tailed prairie dog, Cynomys leucurus. Both species can be destructive to agriculture and rangeland, however, the majority of the issues in the state are associated with the black-tailed prairie dog in the central and eastern counties. Each prairie dog can consume up to two pounds of forage per month, reducing the forage available to other wildlife and livestock. Prairie dogs are carriers of sylvatic plague, an infectious disease caused by the bacterium that causes bubonic and pneumonic plague in humans. Under favorable conditions, prairie dog towns can become dense and naturally expand into areas that directly compete with agriculture, and their burrowing can be disruptive to irrigation and dangerous to livestock.
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Ground Squirrel
Ground squirrels are members of the squirrel family of rodents and generally live on or in the ground. Several different species of ground squirrels can be found in Wyoming, however, the Wyoming ground squirrel, Urocitellus elegans, formerly called the Richardson’s ground squirrel, is associated with issues in the state.
Ground squirrels can compete with livestock for forage and can destroy food crops. Their burrows can damage ornamental landscaping, hay fields, golf courses, and cemeteries. Unlike prairie dog mounds that are dome or crater-shaped, ground squirrel holes are fanned out and typically level with the surrounding landscape. The Wyoming ground squirrel can often be confused with the black-tailed prairie dog, but unlike the black-tailed prairie dog, the Wyoming ground squirrel hibernates over winter.
Get more information:
Colorado State University: Managing Wyoming Ground Squirrels