Earth Notes - Grasshoppers

Flagstaff, AZ – Earth Notes: Grasshoppers

Late spring is the time when Colorado Plateau gardeners begin to see among the least welcome and most frustrating of garden visitors: grasshoppers.

Across the west, agricultural damage from grasshoppers can reach $390 million a year. During some outbreaks they become the dominant herbivore or plant-eater. And the plateau is no stranger to such population surges.

According to Larry Stevens, curator of ecology at the Museum of Northern Arizona, warm winters followed by mild spring conditions are more likely to result in grasshopper outbreaks. Wet winters and cool, moist springs keep grasshopper populations low.

Hattie Braun, with the Coconino County Cooperative Extension Office, recommends getting an early start on controlling grasshoppers. Common control options include tilling the soil, covering plants, and spreading Nolo bait or diatomaceous earth. And some gardeners keep ducks and chickens as naturally hungry pest-control agents.

The Colorado Plateau's grasshoppers are related to the over 22,500 species of grasshoppers, katydids and crickets in the Order Orthoptera that have been cataloged worldwide. Stevens and the Museum of Northern Arizona have so far catalogued 70 species of Orthoptera from the southern Colorado Plateau, with many more left to be documented. But only about a dozen of these species are considered garden or range pests.

Many rangeland managers now acknowledge that grasshoppers are important for ecosystem health even if most prefer to see them in only moderate numbers. After all, grasshoppers recycle nutrients and aerate the soil. And not least they provide a rich food resource for birds, wildlife, and fish.

-Cecile LeBlanc