There have been reports of fall armyworm damage in some wheat fields between American Falls and Firth in eastern Idaho. Please inspect your fields as managing this pest is more effective during the early stages of development. Fall armyworms are active during dark, so field inspections need to be done with a flashlight after sunset. They have a wide host range but prefer grasses; at this time of the year, wheat, barley, alfalfa, volunteers, and pasture are examples of crops that can host fall armyworms. They feed on foliar tissue and can consume young seedlings to the ground. During the day they hide in plant litter and/or just below the soil surface. There are no set thresholds and management recommendations depend on the stages of plant and larval development and the extent of the damage. More than 2-3 larger larvae (> 1/2in) per square foot may require control. Scout as many spots as possible within a field. Damage by fall armyworm is usually patchy and spot insecticide treatment is a possibility, where needed. Larvae cannot survive freezing temperatures and are also susceptible to diseases caused by entomopathogens at high densities.
Large number of grasshoppers and grasshopper damage has been reported from Montana. If large grasshopper populations are present, contact Idaho State Department of Agriculture (ISDA Mormon Cricket and Grasshopper Control Program (link). ISDA’s Mormon Cricket and Grasshopper Control Program provides pest management recommendations and assistance to producers and ranchers across Idaho.
It is time for flies, spiders, and various hemipterans (true bugs) to find refuges in your homes from cold weather. Click here to find some information on prevention and their management.
Wireworms continue to impact cereal production in Idaho. Typically we expect a reduction in wireworm activity later into the summer. This year, however, we continue to collect the insect in considerable numbers in cereal fields. Not much damage is expected at this point since wheat and barley crops are at later stages of development. Delayed growing season, and early-season rainfalls, may explain continued wireworm activity.
If you think that you might have wireworms in your field please contact us for monitoring instruction. Seed treatment and proper rotation are recommended.
Be aware of safflower susceptibility to wireworm damage. Click for information about wireworms and their management.
Late blight has been reported on-farm in Minidoka county. Molecular confirmation is in progress by the University of Idaho.
While the potato psyllids are generally low in numbers in eastern Idaho, their presence is not uncommon. However, keep an eye for any potential zebra chip disease symptoms in potato fields. The disease is not common but it has been reported from Magic Valley and Treasure Valley areas on occasions in previous years.
We have received several reports of Hessian fly infestation in Northern Idaho and Eastern Washington. Our screening program to identify sources of resistance in spring and winter wheat genotypes. These efforts are in collaboration with University of Idaho and Washington State University wheat breeding programs. Click for information about Hessian flies. Contact us for resistant PNW varieties.
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