We had many species of caterpillar both the last two years; so this instance wouldn't fit desparation (I'd think). In fact, our wild grape vines were stripped in less than 72 hours due to larval feeding. Since both these insects were found in my garage, I would guess that the moth had been trapped inside, died, and the the beetle found it. Like hawks and eagles as well as other things of nature, scavenging can be about opportunity and not necessarily necessity. I'll have to keep my eyes open this Summer again to see if there are more instances of this in the garage.