Cattle compete with grasshoppers for food in the West’s historic drought. The bugs win.

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About 93% of the West is experiencing some level of drought this week, and a strange impact of this pernicious drought is the explosion of the grasshopper population. The grasshoppers have devoured so much vegetation that many pastoralists fear the ranges will be bare.
A 2021 US Department of Agriculture locust hazard map shows that every square meter of soil contains at least 15 grasshoppers in parts of Oregon, Idaho, Montana, Wyoming, Arizona , Colorado and Nebraska.

“Climate change is of concern to all of us, and when we see extreme events such as a very severe drought, we see an increase in natural phenomena such as grasshopper outbreaks,” Sharon Selvaggio, former biologist of the United Nations, told CNN. US Fish and Wildlife Service. “This is very worrying.”

Grasshoppers, which thrive in hot, dry weather, defoliate trees and compete with livestock for food – and insects win. Ranchers sell cattle “because of poor forage conditions and a lack of food,” according to the latest US Drought Monitor.

Federal agriculture officials say they saw the outbreak come after a 2020 investigation that found a high concentration of adult grasshoppers in the West.

“Uncontrolled infestations could cause significant economic losses to American ranchers by reducing the forage available on rangelands and thus forcing producers to buy additional feed or sell their livestock at reduced prices,” the USDA said in a report. press release last year announcing a grasshopper removal program.

To mitigate other drought-fueled economic impacts, the agency launched a grasshopper destruction campaign – the largest since the last outbreak in Montana in the 1980s.

Agriculture officials plan to aerial spray more than 2.6 million acres of Montana prairie with insecticides in an attempt to kill grasshopper populations. It is an area larger than the state of Delaware and Rhode Island combined.

This is not the right approach, said Selvaggio, now a pesticide program specialist for the Xerces Society, a nonprofit conservation group that protects habitats from insects, adding that it will be ineffective in the long run.

“The problem with insecticide treatments is that they could actually worsen grasshopper outbreaks in the future by harming natural enemies or locust competitors which under natural conditions serve to control pest locusts,” said Selvaggio.

A 2021 environmental assessment of insecticide spraying in Montana reported no significant impact from large-scale insecticide treatment. The Xerces company and other environmental groups pushed back on the assessment, pointing to a “lack of specificity and clarity” in the report.

The USDA says it will only spray in low concentrations to kill grasshopper nymphs, as adult grasshoppers need larger amounts of insecticides.

And while grasshoppers tend to emerge during particularly hot and dry years, environmentalists say their massive appearance depends on many aggravating factors, including climate change.

Birds, for example, prey on grasshoppers. But the population of grassland bird species is in decline, disrupting the natural cycle of the grassland ecosystem. Vegetation cover, Selvaggio adds, has also decreased, in part due to the way grazing is conducted, which in turn accelerates the development of grasshoppers.

“We have to think of it as a system, not just a symptom of the problem,” she said. “Grasshoppers are a symptom of an unbalanced ecosystem. We need to look at the role of vegetation cover and diversity.”

Selvaggio likens the disturbance of grasshoppers to fire, pointing out that aggressive fire suppression practices in the West have never succeeded in eliminating the risk in the long term. Spraying insecticides to rid rangelands of grasshoppers, she says, will have the same result.

“We need to take a management approach that emulates the natural disturbance regime seen as a better way to make forests and fires resilient,” said Selvaggio. “We need a similar approach for managing grasshoppers on the rangelands.”

U.S. agriculture officials are launching their biggest campaign in decades to kill grasshoppers in Western states amid an outbreak of voracious insects.
A recent climate assessment of the greater Yellowstone area, which is part of the region with dense populations of grasshoppers, warned of significant changes such as outbreaks of invasive species in the region as the planet warms.

This year’s drought and heat waves have broken all records – a clear signal that climate change is already impacting all aspects of life. And because of these extreme climate changes, Selvaggio says how land and ecosystems are managed matters.

“Climate change could bring us more locusts in the future with increased frequency, duration or severity,” she said. “We need these long-term solutions to tackle grasshoppers in the long term, because we know we could face more problems in the future if we don’t take this really seriously.


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