Anxiety rises as grasshopper season begins in North State
By Kathy Coatney Swarms of grasshoppers and Mormon crickets, which travel great distances and destroy crops in their path, are expected to make another unwelcome appearance this year. University of California Cooperative Extension farm advisors say the grasshop- pers, which lay eggs in the fall and begin hatching by summer, are usually more iso- lated to rangeland and irrigated pasture than irrigated row crops. However, exacerbated by dry condi- tions, farmers in Siskiyou and Modoc counties have reported tens of millions of dollars in crop losses during the past sev- eral years due to damage caused by the feeding grasshoppers and crickets. Klamath Basin farmers and ranchers say several grasshopper species destroyed hay, onions and other irrigated crops last year, after the insects left dry wildlife refuges in search of food. Growers say they are anxious this sea- son, since there could be billions of eggs waiting to hatch. Grasshoppers do not like water or wet conditions, so growers are hoping that early rains may have helped in destroying the eggs. Tulelake farmer John Crawford said the
grasshoppers last year damaged his alfalfa and two barley fields, including one organ- ic and one conventional. The convention- al barley was treated and lost some yield. An organic insecticide was applied to the organic barley, but the material had little impact on the grasshoppers. Crawford said he lost 80% of the crop. “I’ve seen a dozen serious grasshopper outbreaks in my lifetime, but I’ve never seen anything that even came close to rivaling last year,” Crawford said. “It was just far beyond anything that we’ve ever had before.” The worst of the grasshopper invasion, he said, came mid-July during the second cutting of alfalfa. The hay came back after irrigation, and by the time growers did a third cutting, the grasshoppers had moved on, Crawford said. Laura Snell, UCCE livestock and nat- ural resource advisor in Modoc County, agreed that rain and cold weather can drown the eggs. “Most of the time, the grasshoppers lay their eggs in drier areas,” Snell said. “If those dry areas are flooded or have a particularly cold, wet winter, populations definitely can be affected.” However, she said, “we did not receive
Affected by crop damages caused by grasshoppers and Mormon crickets in the past few years, farmers are hopeful that excess water this year kills the eggs, reducing the population.
enough cold weather to deter them at all.” In fact, she has already seen significant populations of grasshoppers hatching in the Tulelake area and the lower elevations of Modoc County. Snell said there are two conventional treatments available for grasshoppers. The most effective treatment kills them in the hopper stage before they can fly. She added, “There is a lot more effectiveness if they are in what’s called an early instar,” or developmental phase for the insects. As grasshoppers go through seven levels
of molting and shed their exoskeleton, Snell said the critical stage to treat is when the grasshoppers don’t have wings and aren’t flying. “They are particularly susceptible to chemical applications, and it is when they are eating the most,” Snell said. “For the spray to be effective, they need to consume the grass that’s been sprayed, so you want to be in those early stages when they’re eat- ing a lot of grass.” Crawford said “there are a lot of See GRASSHOPPERS, Page 19
June 5, 2024 Ag Alert 3
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