Yesterday, I was asked to help confirm an identification of a few beetles in a cornfield near State Center, Iowa. They ended up being striped and spotted cucumber beetles. Sometimes the striped cucumber beetle can be confused with western corn rootworm; however, it would be unlikely to see adult rootworms in May. Spotted cucumber beetle is also known as southern corn rootworm (I suppose it depends on if you grow corn or pumpkins). These beetles were feeding on giant ragweed and burcucumber, a weed Dr. Hartzler blogged about last year.
Dr. Laura Jesse, Director of the Plant and Insect Diagnostic Clinic, confirmed striped and spotted cucumber beetles can overwinter in Iowa. They overwinter as adults and emerge in the spring to feed and mate. It is not fully understood where striped and spotted cucumber beetles overwinter or how susceptible the adults are to cold winter temperatures.