Nevada ag officials outline Mormon cricket monitoring, limited sprays and funding constraints for 2025

Jeff Knight, the state entomologist for the Nevada Department of Agriculture, told an Elko County audience that Mormon crickets are beginning to hatch and described how the state and federal partners plan surveys and targeted treatments this spring.

The overview explained when and where the Department of Agriculture and USDA-APHIS Plant Protection and Quarantine (PPQ) will consider treatments, the two principal control tools they will rely on (diflubenzuron, marketed as Dimlin, for aerial use and carbaryl bait for hot spots), and the federal environmental reviews that must be completed before wide-scale spraying.

The timeline and trigger for treatments are biological, Knight said: hatching generally begins in late February to late March when soil temperatures approach 40 degrees, adults appear in late May to late June and effective aerial application of diflubenzuron requires nymphs to be “about half grown.” “Hatching starts in late February, to late March, when the soil temperature gets about 40 degrees,” Knight said. He added that once crickets reach adulthood the chitin-inhibiting chemical is far less effective.

Jordan Jostowski of USDA APHIS-PPQ described how the federal program supports treatments across 17 western states but competes for a limited pool of federal dollars. He said NEPA (National Environmental Policy Act) compliance, endangered species consultations, and human-health and ecological risk assessments are required steps before many treatments can proceed. “We get our authority, for this program from the Plant Protection Act,” Jostowski said, and he noted the program’s EIS and EAs will likely need updates because of recent litigation and program scrutiny.

Officials described the planning metrics they use. The program’s operational threshold is roughly two or more Mormon crickets per square yard on rangeland or where economic or public-safety damage is likely; that threshold triggers nymphal surveys and potential block formation for aerial treatment. The state reported it surveyed about 2,000 sites last year and that Department of Agriculture crews conducted roughly 275 ground treatments and about 70,000 acres were aerially treated, which the agency said translates to roughly 210,000 acres “protected” when reduced‑agent and area treatments are applied.

Diflubenzuron (Dimlin) is the aerial option the agencies prefer for large rangeland blocks; it is a restricted‑use chitin‑inhibitor with a residual the agencies estimate at about six weeks. Jordan Jostowski summarized the formulation used in the program: “1 ounce of pesticide, 4 ounce of crop oil and 8 ounces of water per acre.” Carbaryl bait (commonly sold as Eco brand bait at about 2% active ingredient) is a ground‑applied option for small hotspots; officials said they do not recommend liquid carbaryl sprays or malathion because of their impacts on non‑target species such as pollinators.

Budget and cost sharing were central topics. Peter Rockerben of USDA PPQ said last year’s one‑time congressional allocation for Mormon cricket work in Nevada substantially increased the state’s capacity but that the federal program for the West typically has to divide roughly $500,000 among several states. “We are anticipating for the program as a whole this year to have about a half million dollars,” Rockerben said; he and state staff said Nevada’s likely share would prioritize the highest‑value blocks, and that realistic planning assumes treating a smaller fraction of the acreage proposed. Local governments reported varying participation: Elko County bought and distributed about 5,000 pounds of bait and spent about $22,000; Eureka County assisted with survey and bait distribution but did not conduct treatments; county reports indicated some privately arranged baiting at larger scale but state staff said they are still collecting that data.

Speakers responded to audience questions about household protection and roadside baiting. Knight recommended cricket fences or edge baiting for small parcels and cautioned against placing bait on highway shoulders because bait and carcasses attract more insects and wildlife, creating safety hazards. He also emphasized label compliance and safe pesticide use, and he recounted one intentional poisoning incident (a domestic animal) tied to intentionally laced pellets rather than program baiting.

Officials urged residents to use the program’s new reporting tools: a QR‑linked online form and a live map where reported sightings and spray blocks will be posted. Knight said a public report does not guarantee immediate treatment but helps staff prioritize survey and verification visits.

Why it matters: Nevada agencies and PPQ are balancing the biology of a mobile pest, legal and environmental review requirements, and constrained funding. Jurisdictions and private landowners must coordinate, and buffer/permit and species protections limit where and when aerial treatments can occur. The agencies urged vigilance, accurate reporting, and following label directions for any consumer products.

Looking ahead, officials said planning will continue through spring and that the final acreage treated this year will depend on confirmed nymph surveys, finalized environmental reviews, and available federal and state funding.