Spiders Predate on Fuller Rose Beetles

While surveying a site for Fuller rose beetle, we observed a number of dead beetles with their heads broken off.  We were wondering what might be predating on them, and I caught this spider in the act.  I was disappointed that I did not get a photo of the spider feeding (it dropped the beetle when it saw me), but I did see the spider with its mouth inside the body of the beetle.  The mystery is solved!  Its good to know that something is working on the beetle population.