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Survey and Treatment Projects


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 by filling out this​​ online form.


Dimilin 2L insecticide fact sheet (example diflubenzuron product)

Dimilin 2L fact sheet
Ficha técnica del insecticida Dimilin 2L

Grasshopper & Mormon Cricket photos

Grasshopper & Mormon Cricket photos

Oregon ​​Grasshopper and Mormon Cricket Environmental Assessment (EA)

Grasshopper and Mormon Cricket EA

Oregon Grasshopper and Mormon Cricket Survey Summary for 2021

Survey Summary for 2021

USDA information on grasshoppers & Mormon crickets

Biology, ecology, identification and management of grasshoppers and Mormon crickets in North America. Grasshopper biology, ecology, ID, and management



Todd Adams
Insect Pest Prevention & Management
26755 SW 95th Ave. Suite 101
Wilsonville, OR 97070
Phone: 503-931-0829

​​Colin Park
USDA Animal & Plant Health Inspection Service - Plant Protection & Quarantine​
​Phone: 503-730-7622

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