Utah State University Extension
The pear sawfly, which is actually a wasp, is a common pest on pear, cherry, and hawthorn in Utah. The slug-like appearance of the larval stage has prompted this insect to also be referred to as the pear or cherry slug in various parts of the country.
Jones, Vincent P. and Davis, Ryan S., "Pear Sawfly" (2011). All Current Publications. Paper 930.