Drought conditions over the past few years have allowed a surplus of Mormon cricket eggs to survive underground despite cold temperatures.
The state Agriculture Department has warned that many of those eggs have now begun hatching in the valleys around Reno and across the northern end of the state, from Winnemucca to Elko.
A spokesman said Mormon cricket numbers are as high or higher than last year at this time.
State entomologist Jeff Knight said the department expects to aerially spray 400,000 acres of infested areas.
"We want to keep the crickets out of town, off the highways and away from production fields," Knight said.
The spray is called Dimlin, a growth regulator that causes the crickets to die as they grow out of their shells and molt.
He urged anyone finding Mormon crickets to report them to the Nevada Department of Agriculture Reno office at 688-1182, ext. 278.
