By PR Extension Office

The 2021 Rangeland Grasshopper Hazard map based on adult surveys last summer has all of Powder River County in the red zone, according to Powder River Extension Agent Mary Rumph.

"That means that 15 or more adult grasshoppers per square yard were counted in late July and early August," said Rumph. "Based on the assumption that the adult's laid eggs prior to dying or departure, the outlook for summer of 2021 is grim."

The map is available on the Powder River Extension website: https://powderriver.msuextension.org/

"Several concerned landowners attended grasshopper control meetings last fall", said Rumph, "and many more have contacted the Extension Office since then".

"I am asking landowners who are interested in participating in a grasshopper suppression program through APHIS to contact the Powder River Extension Office by December 10th with an estimated number of private, state and federal acres to be treated," said Rumph. The information will be summarized on a county level and sent to Gary Adams, Director of the Montana APHIS Grasshopper Suppression program, to help project the funding needed for FY 21. Services APHIS (Animal Plant Health Inspection Services) can provide includes surveys, technical assistance and broad scale aerial insecticide application.

The estimated cost per rangeland acre said Adams, is $3.00/acre.

Key points for planning a grasshopper control program for 2021 include:

• Treatment areas with a minimum of 10,000 acres of rangeland are necessary (blocks can be mapped based on landowner interest).

• Dimilin is the product used at 1 oz./Acre. It is a growth regulator that is effective on insects with an exo-skeleton; it is not harmful to bees or birds;

• RAATs (Reduced Agent Area Treatment) is utilized, an aerial swath treatment;

• Treatment with Dimilin must be done at the third instar (which normally occurs in mid to late June);

• Estimated cost to landowners is $3.00 per acre and dependent on the size of the treatment area (bigger is less expensive);

• No treatment will occur if the population doesn't exceed the threshold for control based on early June surveys.

"Funding is limited and will be allocated on a first requested basis," added Rumph. "If we have our request in early, we will have a much better chance of receiving help from APHIS. The information can be provided to the Powder River Extension Office by phone (436-2424), by email, [email protected] or by completing a form on our website at https://powderriver.msuextension.org/.

It is also important to address the question, "Is this treatment effective?"

"In response, I'd like to first remind producers that this is a 'suppression' program; not an eradication program," said Rumph. "I encourage people to talk to landowners in Campbell County, Wyoming, to see what they thought. I was amazed at the results and have had additional confirmation from landowners in areas that were treated in Wyoming and not in Montana," concluded Rumph.