Research Brief: Ecology and Management of the Alfalfa Weevil

Research Brief: Ecology and Management of the Alfalfa Weevil April 28, 2017

If you're growing alfalfa, UNL entomologists recommend a new article in the Journal of Integrated Pest Management: Ecology and Management of the Alfalfa Weevil (Coleoptera: Curculionidae) in Western United States Alfalfa by Makenzie E. Pellissier, Zoe Nelson, and Randa Jabbour. First discovered in Utah in 1904, the alfalfa weevil had spread to to nine states including Nebraska by 1940 and is now found in all 48 lower states. 

The authors review multiple research studies and describe the life stages of this pest as well as its preferred ecology. They discuss feeding injury, abiotic injury, natural enemies, economic thresholds, and options for integrating management strategies, including cultural, chemical,  and biological controls, and host plant resistance. The authors also briefly review contrasting views on systems level management.

Photos of alfalfa weevil at various growth stages are included.

Alfalfa Treatment Comparison
Figure 1. Alfalfa that was treated and untreated for alfalfa weevil. The alfalfa on the left has been treated and has little to no damage, while the alfalfa on the right was left untreated and showing signs of damage (John L. Obermeyer, Purdue Extension Entomology). (Source: Journal of Inegrated Pest Management: Ecology and Management of the Alfalfa Weevil (Coleoptera: Curculionidae) in Western United States Alfalfa)