Blister Beetle + sore?
Location: Southern Missouri
May 18, 2011 10:44 pm
Daniel, I live in Southern Missouri and have recently been waking to nocturnal ”bites” that produce an intense burning sensation but no sign of an actual bite until a day or so later, when a sore appears (2nd photo). This beetle may be the culprit because it has recently shown up in our home. I can’t find it in your blister beetle archives, however. Can you help? Thanks, Bob
The beetle you submitted is not a Blister Beetle, but a False Bombardier Beetle in the genus Galerita, and it is a Ground Beetle. You may read more about it on BugGuide, including the warning that “Caution: These beetles have chemical defenses (see Rossini et al. 1997)”. Following that link to the Proceedings of the National Sciences of the United States (PNAS), we learned that the spray contains formic acid and that “Formic acid is a potent irritant, deterrent to vertebrates and invertebrates alike.” Your letter specifically states you are waking to nocturnal “bites” but since bites is in quotes, it seems you have some doubt that they might actually be bites. We don’t believe the False Bombardier Beetle to be responsible for your sores, though we might be wrong. We can’t imagine that a beetle that has chemical defenses that need to be replenished would actually expend those chemicals unless it really felt threatened. False Bombardier Beetles are beneficial predators and one should avoid handling them. We are going to tag this posting as a mystery and we truly hope the False Bombardier Beetle is not the culprit, but that would mean something else is lurking between the sheets.