I was out for a walk with my daughters  last Saturday, and we went for quite a long way on the trails through the woods behind our house. And, at the point furthest from the house, I spotted this big, fat insect lying in the grass, stunned by the cold:
As it turns out, I knew what this one was right away, because I had seen something like this before, in 1995, and had it identified for me then by Doug Yanega. It is an Oil Beetle in the genus Meloe, most likely either Meloe angusticollis or Meloe impressus
This particular one is probably a female, because her antennae are pretty straight. Males have a pronounced kink in the middle of their antennae, and are a bit smaller than this.
It looks big, fat, and succulent, and it would seem like any passing bird would snap it right up, but appearances are deceiving. As it turns out, they have a good defense mechanism. That huge body is loaded with a blistering agent, so anything eating it is in for a very uncomfortable meal. When they feel threatened, they also ooze the blistering agent as an oily yellow liquid from the joints between their body segments (“reflex bleeding”). That’s why I was handling it with tweezers in the previous pictures, it could have been quite uncomfortable to get that stuff on my hands.
The abdomen is so huge that it has trouble even walking, let alone flying, so the wings are kind of vestigial. There’s just enough of the wing covers left to identify it as a beetle, but not enough to actually do any good.
The head is pretty ant-like, but the antennae are distinctly segmented and are much more like what one expects from a beetle.
These are parasitic beetles, that prey on solitary ground-nesting bees. What they do is this: the eggs hatch out in the spring, into a small, fast-moving larva. This larva goes and hides out in a flower blossom, and waits for a solitary bee to come by. When one does, it leaps onto her while she’s gathering pollen, and then rides back to her nest. Once there, it slips in and waits for her to finish stocking it and laying her eggs. Once she finishes, the beetle larva molts into a grub, and settles down to consuming her egg and all those provisions before pupating into a beetle. The beetle then crawls out of the bee nest in the fall, finds another beetle to mate with, and then they lay eggs. Since the solitary bee nests tend to cluster together in spots with suitable soil, the beetles usually find other beetles nearby, so they don’t have to travel far to find mates. And, since the larvae end up getting carried around by the flying bees, they can get most of the benefits of flying without actually being able to fly themselves, so their wings have atrophied away.
Oh, this is interesting: while the species I have here probably doesn’t do it, there is at least one Meloe species that has a neat trick for getting onto their hosts. Newly-hatched Meloe franciscanus larvae will climb up onto something in a group and form a mass that smells, and to some extent looks, like a female bee. Then, when a male bee flies by, he thinks they are a female and tries to mate with the mass of beetle larvae. At which point the larvae swarm onto him and go for a ride. Then, when he really does find a female bee, the beetle larvae go onto her, and then get carried to her nest. Pretty sneaky.
 More of two walks and a carry; Rosie isn’t up to walking much on rough trails yet, so I had to carry her the whole way (luckily, she’s just old enough to ride up on my shoulders). She’s a real speed demon on smooth floors these days, though. Sam can walk in the woods just fine, although sometimes she complains that I walk too fast.
 Sam has been naming the trails. The main trail that goes through our back yard and into the woods is “Clover Weevil Road”, the first one branching off into the woods is “Leaf Road”, and the one running under the power lines is “Tall Grass Road”.
 It was about 38 F at the time, so I wasn’t really expecting to see many insects, especially considering that there had been a couple of inches of snow on the ground just a few days earlier. Later that day, it warmed up to the 50s and we actually saw a live grasshopper, which was a surprise.
 Back in 1995, before we were married, S_ and I were going for a walk on the Baraga Plains, about 40 miles south of here, and we found one of these hanging out at the top of a grass stem. Huge, electric-blue insects kind of draw the eye. Now, one thing we both knew was that a big, fat, uncamouflaged insect like that would normally be just screaming to the world at large, “Eat me! Eat me!”, and so the fact that nothing had eaten in yet was a pretty strong sign that there was a good reason not to eat it. Of course, I go and pick it up to get a better look. S_ asked, a bit apprehensively, “Are you sure it isn’t dangerous?”, to which I said something like, “This is Michigan, nothing is very dangerous”. All this time, I was looking it over, and noting, among other things, the yellow liquid oozing out of the joints between its body segments. Which, luckily, I did not actually get onto my skin. Then, once I got the identification from Doug Yanega, I felt pretty stupid once I realized what the yellow liquid was. I apologized to S_ for that later.
 Those are special flexible insect-handling tweezers from BioQuip. They are springy enough that you can pick up fragile insects without crushing them, which makes them much more useful than conventional tweezers.
 (activating Geezer Mode) This was back when the big way to get your questions answered online was to post it on Usenet. The “sci.bio.entomology” newsgroup had only existed for a short time in 1995, so that was where I went to ask about the beetle. Yanega was one of the professional entomologists who used to read the group, and was very helpful to a lot of people.