Predicted Mortality of Bean Leaf Beetle Is Highest in 25 years

Bean leaf beetle adults are susceptible to cold weather and most will die when the air temperature falls below -10°C. However, they have adapted to winter by protecting themselves under plant debris and loose soil. An overwintering survival model was developed by Lam and Pedigo from Iowa State University in 2000, and is helpful for predicting winter mortality based on accumulating subfreezing temperatures. Predicted mortality rates in Iowa were extremely high during the 2013-2014 winter and ranged from 89-99 percent (Fig. 1). Not surprisingly, central and northern Iowa experienced colder temperatures, and most of the bean leaf beetle adults are not expected to survive