Brood XIX periodical cicadas were not the only insects appearing en masse last week at Sam A. Baker State Park in Missouri’s southeastern Ozark Highlands. As I walked the upland trail, I thought I felt ‘raindrops’ for awhile before realizing that it was frass. Little pieces of fresh young leaves littered the trail around me, and I realized that an outbreak of caterpillars was hammering the oak trees in this forest. Unlike the cicadas, which were encountered primarily in the bottomland forest along Big Creek, the rain of poop was restricted to the uplands. Not surprisingly, I saw caterpillar hunters, Calosoma spp. (family Carabidae—the real Carabidae, not the tiger beetle Carabidae that I’ve begrudgingly had to accept) about as abundantly as I’ve ever seen them. At first I didn’t notice them until I would scare one up, then spend several frustrating minutes trying to photograph a beetle that just would not stop running. I tried a few and gave up—after all, they’re just ground beetles (i.e., real ground beetles). Eventually, I realized that if I noticed them before they noticed me, I could sneak up on them and have my way with them (photographically speaking, that is). I even found that I could preen nearby leaves and sticks for composition if I did it carefully enough. Here are a couple of my favorite shots on the day.
I would presume these to represent the fiery searcher, Calosoma scrutator, but apparently C. wilcoxi is similar in appearance. According to comments by several BugGuide users, C. scrutator is larger (25mm or more in length), has more elongated mandibles and head, and the color of the central purple area of the pronotum is more intense. Based on those comments, I would say the two individuals in these photographs are C. scrutator. However, they also note some differences in temporal occurrence that don’t seem to support that. Moreover, the many individuals I saw that day ranged in size from these larger individuals to some notably smaller ones.
Copyright © Ted C. MacRae 2011