In the summer of 2022, Oregon had an estimated 5.3 million infested acres in 18 counties. At economically infested sites, grasshoppers reached an average density of 73 grasshoppers per square yard (8 or more grasshoppers per yard can cause significant damage to rangeland). Out of 6,364 sites surveyed, 42% had economic infestation levels of grasshoppers.
Grasshopper outbreaks often follow or coincide with drought years. Low rainfall and warm spring weather support egg hatches and survival of small grasshopper nymphs. As a result, grasshoppers develop rapidly. These conditions also reduce the impact of predators and diseases that limit grasshopper numbers.
Grasshopper outbreaks mean less forage and vegetation cover essential for livestock and wildlife. Less vegetation leads to environmental damage and erosion. Starving grasshoppers may also invade agricultural areas where they eat crops.
How to report grasshopper outbreaks
Report a grasshopper outbreak or request a survey by filling out an online form to find out if treatment is advised.