CASPER, Wyo — University of Wyoming Extension entomologist Scott Schell says parts of Wyoming could see an outbreak of pestilent grasshoppers this year, based on population surveys in the summer 2019.
Schell published “Landowners Should Be Aware 2020 Could Be a High Grasshopper” in the UW Extension’s free Barnyards and Backyards Rural Living Magazine for Spring 2020.
The article states that areas of the state that had seen high numbers of grasshoppers last year will likely see more this year, as their eggs, having lain dormant over winter, hatch in the spring.
Grasshopper populations are tracked by density per square yard. 1-7 grasshoppers per square yard is considered normal. At densities over 14 per square yard, 30% of available rangeland forage is consumed or damaged, according to the article.
2019 population surveys by the United States Department of Agriculture identified a number of areas in the central and eastern portions of the state that exceeded 15 grasshoppers per square yard, according to information in the article.
Schell stated that pest species hatch in weedy areas along fencerows and spread to crops, gardens, and yards in early summer. Only a dozen of the 120 species of grasshopper in Wyoming are considered pests, Schell said.
He said migratory species of grasshopper pose the biggest problems, and compared them closely to locusts. When their preferred food sources of grass and forage are depleted, they move on to prairie sagebrush, affecting sage grouse and mule deer. They will even consume deciduous trees and wooden window frames.
Other experts have said that grasshopper populations thrive when winters are milder.
Pest control is managed by county districts with cooperation from the USDA. Mitigation tactics include spraying with insecticide and limiting overgrazing.
