Utah State University Extension
Billbugs can be a serious turfgrass pest throughout the entire U.S., with at least eight species known to occur. In Utah, two species have been detected (Denver and bluegrass billbugs) and reported to cause turfgrass damage. Although not a new pest to turfgrass, billbugs are often ignored or misdiagnosed, and root decline is confused with drought stress, fungal disease, or other insects.
Hodgson, Erin W., "Billbugs" (2007). All Current Publications. Paper 861.