We established economic injury level for alfalfa weevil in alfalfa hay system under the southwest low desert conditions of the US. We developed an app to be user-friendly for growers and pest control advisors who rely on the aspects of established economic injury level to make and informed decision to manage alfalfa weevil in the region. Early mitigation of the weevil’s larvae proved to be key for effective management of this insect. Resistance monitoring in many western states showed mixed results; some region are developing resistance toward some insecticides, especially pyrethroids, while the insects seems susceptible to this group of insecticides in other regions. we also conducted lab and field experiments to study the efficacies of certain entomopathogenic fungi to control alfalfa aphids in the region. Field studies showed promising results for commercially available formula of an entomopathogenic fungus belongs to Isaria sp. Natural infection of different entomopathgenic fungi are effective in areas where managing irrigation is adapted to keep higher humidity under alfalfa’s canopy. Overall, blue alfalfa aphid is the most destructive among other alfalfa species to yield and quality, mainly due to its capabilities to insert toxic inside alfalfa plants.
