Montana Department of Agriculture

Cooperative Agricultural Pest Survey Program

Silver Y Moth Detection and Delimitation Survey Report

2005

Compiled by Will Lanier

The Silver Y Moth (Autographa gamma) is an emerging pest (Ranked 2 on the Western Region Pest List) of various crops including both potatoes, broadleaf and cereal grains. The Silver Y Moth (SYM) detection and delimitation survey was designed to determine if SYM, is found in Montana. If SYM was found, the trapping program would give some indication of the extent of the infestation.

A network of pheromone trapping sites (@40) managed by individual site cooperators (4-H, Extension agents and producers) for detection of a number of native cutworm moths already operates in Montana. The proposed survey added 40 PheroTech Uni traps baited with pheromone specific for Silver Y moth, Autographa gamma, to the current network.

Sampling was conducted in Beaverhead, Big Horn, Blaine, Cascade, Chouteau, Custer, Powder River, Daniels, Dawson, Fallon-Carter, Flathead, Gallatin, Glacier, Hill, Judith Basin, Liberty, Phillips, Pondera, Prairie, Richland, Roosevelt, Sweet Grass, Teton, Toole, Yellowstone and Carbon counties.

Each week for 8 weeks beginning approximately Aug 1^st. cooperators install and begin monitoring the number of moths caught in pheromone traps. Each week the catches are recorded and data is submitted to allow the Cutworm Risk warning for that area to be estimated. During the cutworm trapping process the contents of the SYM traps were be bagged and refrigerated until they were mailed/delivered to the MSU Schutter Diagnostic lab.

Trap examination and identification of suspect moths were done in a tiered system, with the insect diagnosticians at Montana State University (Bozeman) first examining the specimens following a dissection protocol developed by Richard Worth, Lepidopterist & Insect Program Specialist at the Oregon Dept. of Agriculture, Plant Division, conferring with MDA State Entomologist and if necessary confirming identifications with USDA specialists.

No SYM were collected in 2005. The majority of our specimens were Alfalfa looper (A. californica) with a few unknowns that were not A. gamma.