She caught it pretty easily, because its front left wing was badly deformed, and all it could do was flutter about. It evidently didn’t inflate properly when it changed from the larval form.

Adult antlions can easily be mistaken for damselflies, which have similar body shapes, head shapes, and wings. The big giveaway is the antennae: antlions have medium-length antennae-

that end in a somewhat fattened hook-

while damselflies barely have any antennae at all. Antlions evidently aren’t as strong of fliers as damselflies, either, and when they flap their wings it makes kind of a soft, breathy noise, sort of like a moth.

I’m not sure what, if anything, the adults eat. They have pretty minimal mouthparts-

unlike the rather startling jaws of death that the larval form has-

so they may just be mating machines that emerge, mate, lay eggs, and then die of starvation.

I was a bit startled to see just how huge the adult was (almost two inches long) compared to the larva (about half an inch). They evidently are very flimsily constructed as adults, with a very low body density, so they are able to stretch their larval mass out to fill a lot of volume.

There are two ways that I’ve seen recommended to collect the adults: (1) set out a sticky trap near a light at night, or (2) find one of the larval pit traps, keep it as a pet, and catch the adult after it pupates. Catching a deformed one like this one during broad daylight was quite a stroke of luck.

Last year, we found ant lion larvae with pits in the yard in the spring, then they disappeared around July, and then they reappeared in August.  Since S_ caught this adult in July, it looks like the lifecycle of the local antlions goes something like: lay eggs in late July, grow up partway, and then overwinter as half-grown larvae. Finish growing in the spring, then pupate in late June/early July, emerging as adults to lay eggs in July.  Of course, this assumes there is just one generation a year.  We should probably raise one at some point to see just how long the local species lives.

It’s a soil centipede, order Geophilomorpha. These are actually getting close to deserving the name “centipede” (”hundred-legger”), because for this one I count 39 pairs of legs (78 legs total). Some other species of soil centipede actually do have over a hundred legs.

An interesting point about centipedes (or at least, I think it is interesting): the different types of centipedes are actually quite distantly related to each other. Notice I said it was in the Order Geophilomorpha. The Stone Centipede that I posted a while back (and that we found under the same rock) is in the order Lithobiomorpha. Since they are in different orders, they are no more closely related to each other than, say, beetles are to butterflies. And other “myriapods”, like millipedes, are about as closely related to centipedes as they are to lobsters or spiders. I understand that the biologists currently think that the “myriapods” are pretty much what the ancestral arthropods looked like.  We evidently have a bunch of distantly-related groups that, even though their last common ancestor was a long time ago, didn’t happen to evolve in a way that changed their body morphology too much.  As a result, they still all look generally similar to each other even though they probably became separate groups sometime before there were dinosaurs.

Anyway, soil centipedes are generally carnivorous, and run under leaf litter and down earthworm holes to eat other small things that they find underground. These are enough smaller than the stone centipedes that I can’t really see them being any harm to anyone, and I don’t see any sign of poison claws in these pictures (although, to be fair, the heads are so small that it’s hard to see details). They evidently don’t have eyes, because, well, why would they have them? What is there to see under a rock, anyway? Normally, you probably won’t even notice these until you go specifically looking for them, but as soon as you look closely they are probably all over the place anytime you start digging.

Chirp of Spring Field Cricket (.wav file)

There’s actually two very similar species of field crickets around here, they look the same, sound the same, and pretty much act the same. The only observable difference is that the spring field crickets like these overwinter as nearly-mature nymphs and sing in the late spring, while the fall field crickets (Gryllus pennsylvanicus) overwinter as eggs and don’t sing until fall.

Back in April, Sam had caught for me a spring field cricket nymph. You can tell it is immature, because it doesn’t have any substantial wings yet, but it had clearly overwintered as a nymph in order to be this big so early in the spring.

In contrast, last year in late May, S_ caught this much smaller cricket nymph in the house. Since it was so small so late in the spring, it had evidently overwintered as an egg and just hatched out recently. It is therefore a Fall Field Cricket, and wouldn’t be mature until the end of summer.

On June 25, I happened to find a whole clutch of the spring field crickets in the yard[2], and caught both a male and a female.

There are a couple of obvious differences between the males and the females. First of all, the males are the ones who do the singing, by rubbing their wings together. They therefore have larger, heavily-veined wings, with the sound-making apparatus supported by the veins.

The females, on the other hand, have smaller, simpler wings without the heavy veining structure.

Of course, the most immediately obvious difference between the males and the females is that the females have a long, swordlike ovipositor for laying eggs, while the males do not.

There are two other long projections on the back of the abdomen, these are the “cerci”, and the males have them too. If you look closely at the cerci, there are fine hairs all over their surfaces. These hairs are socketed so that they can only move in particular directions when they are hit by a puff of wind. This gives the cricket a pair of very sensitive and highly directional detectors for bursts of wind caused by, say, a lunging spider, a toad flicking out its tongue, a bird swooping down, or a small child trying to snatch it. This is how crickets know to jump when something tries to grab them [3].

Field crickets are also astoundingly slippery, making them hard to hold onto, and like other crickets and grasshoppers they have spines on their hind legs that can make them unpleasant to eat. This is important, because they are otherwise extremely succulent insects, quite large and tasty-looking. Without some defense, they are sure to be somebody’s lunch [4]. They make excellent fish bait, and are usually easy to find by flipping over rocks, even when it is too dry out to find worms.

————–
[1] The voice asking what I was doing about halfway through is Sam, my oldest daughter. She was curious why I seemed to be taking a movie of a blank, grass-covered hillside.

[2] We have a fold-up cloth-covered stroller that had been left on the back porch overnight. I picked it up and unfolded it, and it was full of crickets.

[3] Cockroaches, and a lot of other insecs, also have these structures that they use to sense danger. In the “Spider-Man” comics, Peter Parker’s “spider sense” is actually a lot more like the air-pulse sensing of a cockroach or a cricket than anything a spider can do, but I suppose “The Amazing Cricket-Man” wouldn’t make as snappy of a comic book title.

[4] When I finished photographing these, in fact, they went to feed Sam’s tarantula. The tarantula is pretty lackadasical about her eating habits, and ignored the crickets for some time. The male started chirping to court the female within about 30 minutes or so, and we were able to watch how he did it: he lifted up the wings to about a 30 degree angle to his body, and moved them rapidly from side to side, with their inner edges rubbing over each other to produce the chirp. It looked like the rest of the wing surfaces acted as sounding boards to amplify the sound. He kept this up most of the night, but at some point that morning the tarantula evidently decided she’d had enough, and ate him[5]. Everybody’s a critic.

[5] Update: the tarantula really, really loves these.  Once she got a taste of the first one, the second one only lasted a couple of hours, and the two that we’ve fed her since then have both been pounced on in less than a minute. This is in contrast to the crickets from the pet shop that were the only things that she had been fed previously, and which she used to ignore for hours or days before finally rousing the interest to eat one. I guess free-range crickets are a lot tastier than the store-bought kind.  Isn’t that usually the way these things work?

This is certainly one of the Calligrapha leaf beetles[1]. Based on the dark green pronotum (the plate between the head and the wing covers), it looks like it is related to Calligrapha alni, the Russet Alder Leaf Beetle. I’m not so sure it is that exact species, though. While the pattern on the wing covers is very close, the examples in Bug Guide show more of a rusty coloration, and a bit less gold.

If it is the Russet Alder Leaf Beetle, then it eats (Surprise!) Alders. Most likely, they are eating the shrubby alders that grow around here in boggy areas, and specifically in the boggy area just north of our house. These beetles are not particularly common, and the plant they eat has negligible economic value, so as you might guess, this is not a particularly well-studied beetle.

I’m not seeing any specific description of what their larvae eat, or for that matter a lot of information about them in general[2]. It looks like lot of other leaf beetle larvae eat roots of the host plant, and the adults then come topside to eat the leaves, so there is a good chance that the larva of this one live underground and eat alder roots.

———–
[1] I expect that they are named this because the patterns on their wing covers look like fancy calligraphy.

[2] If you are a professional entomologist trying to make a living, you have to spend most of your time studying things that someone will pay to know something about. That means that things like crop pests, or insects that prey on crop pests, or insects that have direct economic value (like honeybees or mealworms) get studied a lot; insects that have no particular economic value, but are either visually striking or very common, get studied a bit; and insects that are neither economically significant, common, nor otherwise striking basically barely get studied at all. And even when an entomologist has the wherewithal to study the more obscure bugs just for the sake of it, entomologists are pretty thin on the ground, so they can’t be everywhere and will naturally miss a lot. As a result, entomology is one of those fields where an enthusiastic amateur can actually make a real contribution. The big issue is for all the amateurs to be able to compare notes and compile their information in accessible locations, like BugGuide. Or, for that matter, to publish in journals like The Great Lakes Entomologist. As long as the observations are carefully made and the information is presented clearly, they don’t care whether you are a “professional” entomologist or not.

Water striders are a bit unusual, in that they don’t live exactly in the water, or in the air. Instead, they live on the interface, supported by the surface tension of the water. A good picture of one in-situ is here. The tips of their long legs are supported on the surface, with a long, narrow foot to spread out the weight enough that they don’t punch through.

Other than being long, the foot doesn’t have any obvious structure to help the water strider stay afloat. However, the whole insect is highly water-repellent: when I released them, I poured them back into the water, and they bobbed to the surface instantly, still dry as a bone.

Water striders are the family Gerridae, and these are probably in the genus Aquarius. They use the four long legs to skim along, and use their front legs to snatch other small arthropods through the surface of the water

They are true bugs, and have the typical bug-style sucking mouthparts. This one flashed its proboscis so that we can see it properly:

While they are obviously most at home on the water, they can go onto land if they want to. I dropped one onto the kitchen floor, and while it was kind of clumsy, it could move along all right. And, when alarmed, it could jump surprisingly well, clearing up to 5 inches on some jumps.

I then noticed there were several others flying about, so they are obviously something really common. It looks exactly like a Red Turpentine Beetle, Dendroctonus valens. This is a pretty likely identification, because (a) they are well-known pests of pine trees, (b) there is a pine plantation just behind our house, and (c) they emerge as adult beetles very early in the spring.

These are pretty robust little beetles, built like tiny tanks. They tolerate cold, and can push other beetles around pretty easily[1].

Unfortunately, it wouldn’t stay still for an extended depth of field shot, so here’s another where the legs and antennae are in better focus.

They have a pretty deep body, they are almost cylindrical in shape, which I expect gives them more room for musculature to do what they are evolved to do: bore under tree bark. Their eyes aren’t all that prominent, for the obvious reason that they probably don’t need them all that much.

They do have pretty aggressive mandibles, though. Here it is trying to gnaw a hole in my finger (it didn’t succeed):

It also flashed its wings at me a couple of times. The flight wings are these long, membranous affairs with a hinge in the middle, so that they can fold up neatly under the wing covers to avoid damage[2]. It was a lot quicker on the wing stowage than most beetles, it could go from wings fully deployed to wings completely tucked away in about 3 seconds, which is why we have to settle for a somewhat blurry picture of it here.

This is another case where we see that pest species get a lot more attention than species that are just kind of around. Since red turpentine beetles can kill pine trees, and pine trees are an important crop, a search on the name turns up a lot of Federal and State forest service sites talking about them. It turns out that, even though they are common and widespread in North America, they are considered a minor pest[3] because they rarely build up to epidemic numbers, and usually only kill trees that have been weakened by other causes.

Their life cycle goes like this: In the spring, adult beetles chew out a “gallery” underneath the bark of a pine tree, where they lay eggs in the living part of the wood[4]. The eggs hatch out, and the legless larvae burrow under the bark[5], growing for up to two years (in cold climates), or sometimes having two or three generations in a single year (in warmer climates). They overwinter as pupae under the bark, and the adults hatch out in the spring.

Red turpentine beetles are mainly a problem if trees are damaged by fire, or get injuries from logging equipment when a pine plantation is being thinned, or if living branches are pruned off of the tree[6]. The beetles can enter through undamaged bark, but most healthy North American pines can exude enough pitch and resin into the beetle galleries that they can prevent eggs from being laid and hatching[7]. A sick tree, or a tree with bark damage, can’t produce enough resin to protect itself, and so the beetles are able to get in and seriously damage or kill the tree.

So, these beetles probably aren’t causing any major damage to the local trees, but they are certainly here, and they are something to watch out for. The main defense against them evidently is just to keep your trees healthy, unwounded, and unstressed. Pesticides don’t work all that well, because the beetles and larvae spend almost all their time under the bark, where sprays won’t get at them.

—————–
[1] See, we’d been catching various types of beetles and putting them together in a jar in the refrigerator until I had time to photograph them all. So, I had dumped this one into a dish with two other beetles, thinking that they’d generally lie still. The other two were pretty stunned by the cold and mainly just lay there, but the red turpentine beetle kept marching around the dish, bulldozing them out of the way whenever it came across them. For its size, it’s a pretty unstoppable little beast.

[2] The basic insect body plan has 6 legs and 4 wings. Most insects that fly use all four wings for flying, but the beetles have modified their first pair of wings into protective covers for the rear wings, which they actually use to fly. This is one of the reasons why beetles are so successful: they get the advantages of having wings available when they need to travel long distances in a hurry, but they can also get into the rough-and-tumble of life without risking damage to their wings, or even having their wings get in the way. This makes them way more durable than other winged insects.

[3] Of course, if they get outside of North America, it’s another story. They are an invasive pest of pine trees in China, where the local species of pine trees have never built up any significant resistance to them. They’ve evidently been fairly devastating to Chinese pines in Shanxi Province and adjacent provinces since about 1999. We constantly hear about invasive species from Asia causing problems on other continents, but this just goes to show that the problem can go both ways.

[4] Even though trees are pretty large, most of the volume of a mature tree is dead. The only part of a tree trunk that is actually alive is the thin layer between the bark and the woody core. This thin layer is the only way for nutrients to travel between the roots and the leaves. If it is damaged in a large enough portion of the trunk to the point that it can no longer transport nutrients, then part or all of the tree above the damage gets starved for nutrients and dies. And, of course, bark beetles eat this part of the tree, because it is the most nutritious part of the whole plant.

[5] Woodpeckers love bark beetle larvae, this is one of the main things they are after when they go drilling away on trees. So, if you see a woodpecker pecking away at a tree trunk, it is a pretty good bet that the tree is already in a bad way and likely to die from something like a beetle infestation. By this time, the damage to the tree by the woodpecker is almost beside the point.

[6] This is probably one of the reasons why it is very rare to see pine plantations where the trees are pruned, even though pruning the trees would in principle make them grow straighter, reduce the number of knots, and in general make them much more valuable as lumber. If the pruning operation leaves the trees vulnerable to bark beetles like this one, then pruning could lead to unacceptable losses of the trees if the plantation is in an area where the beetles are present.

[7] If you look at pine trees, you’ll often see these yellow, sticky pitch blobs on the trunk. These are the tree’s response to bark damage. If the pitch is from a wound made by these beetles or other beetles like them, the pitch is mixed with “frass” (insect droppings and sawdust).

It had obviously overwintered as a caterpillar, it certainly hadn’t gotten that big in the approximately 3 above-freezing days that we’d had at that point. It looked it, too - a bit weathered, kind of scruffy, not moving very fast. It’s certainly a caterpillar of some type of tiger moth, in the family Arctiidae. These are pretty large moths that have fuzzy caterpillars, like the well-known wooly bear caterpillar. This one isn’t a wooly bear, but I think it is the caterpillar of one of the moths in the tribe Arctiiini. BugGuide is kind of short of caterpillar pictures here, but from Wagner’s book I’m inclined to think it’s either the Great Tiger Moth, Arctia caja, or the St. Lawrence Tiger Moth, Platarctia parthenos. Unfortunately Wagner’s picture of the St. Lawrence Tiger Moth caterpillar doesn’t look quite right either, but he does say that it is more uniformly dark than the Great Tiger Moth, with brown spiracles. I can’t see the breathing spiracles at all, so they must be brown:

The head is black, too, instead of brown

And the setae (hairs) come out of a kind of warty tuft instead of being spread uniformly over the body

So, on balance, I’m leaning towards the St. Lawrence Tiger Moth, but in either case, the caterpillars are pretty similar as far as habits. They overwinter as partially-grown caterpillars, and then eat a bit more in the spring before pupating and emerging as adult moths. They aren’t very fussy about their food, eating grass, legumes, and pretty much any other low-growing plants that are available. Wagner refers to them as the “musk oxen” of caterpillars, because they are big, hairy, and shrug off the cold. They are also rather long-lived, the St. Lawrence Tiger Moth can take two years to get to adulthood, overwintering twice.

This is a “stone centipede”, order Lithobiomorpha, so called because that’s what they live under[1]. They run like water, flowing around obstacles and into holes in a way that’s very much like the way a stream of water flows, and are kind of hard to catch. On top of the speed, they are slippery, and their dozens of legs are very good at forcing them through crevices, or out from between your fingers. Even their antennae have a disturbingly fluid nature, flowing over surfaces and contorting in a way that is more like what you would expect from tentacles than from antennae.

That first picture was low-magnification because the whole centipede is much too long to fit into a single high-magnification image. Here’s a few showing it in more detail:

In the picture of the head end, you can see two bulges on the sides of the head. These are the “poison claws” that they use to grab their prey. Here’s a (somewhat blurry) picture showing the claws opened and looking very ominous:

Getting back to the body, here is the midsection:

While stone centipedes do have lots of legs, they don’t have a hundred legs. This one would have had 30 legs, except that it is missing one of the rear ones. There is one pair of legs per body segment, even though some of the legs look like they are coming from the junctions between segments. This is because the body segments are wildly variable in size, with some of them being practically nonexistent. I’m not sure why that is, I would have expected all the body segments to be about the same size.

The last few sets of legs point almost straight back, which doesn’t seem like it would be all that helpful for walking. Maybe they are used to push forward? Mostly, it just seemed to drag them around.

While stone centipedes are reputed to be able to “bite”, once again I can’t confirm that. I was picking this one up and pushing it around, and it was doubtless pretty annoyed with me, but it didn’t let me have it with the poison claws. I understand that some of the big tropical centipedes have pretty painful bites, but as I’m sure everyone has gathered by now, Upper Michigan is hardly the tropics[2].

Anyway, stone centipedes are pretty aggressive predators, preying on the other things that live under rocks like woodlice, worms, springtails, grubs, and who knows what else. They are easily the fastest-moving things you are likely to find under a rock, and their thin body shape makes it easy for them to squeeze quickly into crevices.

They are pretty stong, too. I had this one in my photographing dish with a glass slide over it, and it was strong enough to muscle the slide aside and crawl out. Then it was off like a shot, and I had to scramble to catch it again (this was when it had a really good opportunity to bite me, but didn’t take it). I ended up having to hold the cover slide down with my finger to keep it from getting away again.

—————-
[1] I was looking at the “categories” list on the sidebar, and noticed that while I had multiple specimens for the other major classes of arthropods I’m likely to find around here (arachnids, crustaceans, and insects), for the myriapods there was only this one, lonely millipede. So, Sam and I went out flipping over rocks to find some more myriapods to fill out the list a bit.

[2] The term “subarctic” comes to mind[3], although I guess it is officially classified as a “humid continental” climate. I know a faculty member at the University who was visiting the Soviet Union (back when there was a Soviet Union), and mentioned where we were located. The Soviet professor he was talking to was convinced that our university must be the US Government’s equivalent of Siberia for exiling politically-disgraced scientists. I dunno. Maybe it is.

[3] The Keeweenaw Peninsula was just about the last place in Michigan to come out from under the ice at the end of the last ice age: the glaciers from the “Marquette Readvance” didn’t melt off until about 9,900 years ago, several thousand years after the lower peninsula of the state had melted off completely. Even then, a lot of the U. P. was periodically inundated for the next several thousand years until the lake levels stabilized. That sounds like a long time for wildlife to recolonize the area, until one considers that wingless arthropods like centipedes had to walk about a thousand miles to get up here since the ice melted. A mile every 10 years or so doesn’t sound that hard to us, but to critters less than an inch long that can’t fly, it’s a pretty fast clip. The centipedes move fairly briskly, so they probably got here comparatively quickly (maybe 5000 years ago), but things like woodlice must have had a hard slog of it (unless they hitch-hiked on birds or something). Some of the slower creatures, like earthworms, didn’t make it up here at all until they were carried up by human activities (earthworm eggs in mud stuck to tires, or abandoned fishing bait, for example). So, even though a lot of the things that live in the soil in, say, Ohio could probably live just fine up here, they just haven’t gotten this far yet.

It’s a jumping spider that mimics an ant[2]. It’s about the size of the Formica ants we have around here and looks a lot like them. The mimicry extended to its behavior, too. While I was catching it, it pointed its abdomen at me in a threatening sort of way. This is the same pose the ants take when they are annoyed, just before they spray formic acid. So, any predator that had a previous run-in with a Formica ant is likely to assume it’s about to suddenly get another facefull of acid, and beat a retreat. The mimicry is a nice, neat solution to predation for the spider, that works OK for as long as the ants are a lot more common than the spiders.

You can see how much the abdomen looks like the abdomen of an ant here. It even has white lines across it to simulate a segmented abdomen, because ant abdomens are visibly segmented but spider abdomens aren’t:

The coloration is pretty similar to the Formica ants, with a black abdomen and the rest of the body dark red. The mimicry falls apart at the head end, which doesn’t look all that ant-like, but that probably doesn’t matter so much. An attacking predator is going to be confronted by the abdomen, and probably won’t even see the head.

I wanted to get some pictures of the face so we could see the eyes, but like a lot of spiders it has the annoying habit of scrunching down with its legs arched over the face. It didn’t want to move, so I tried nudging it a bit with a toothpick to get it to reposition the legs. Unfortunately, this prompted it to suddenly leap out of the dish, dash across the table, and leap off into the nearby bookshelves. It got away clean, after I’d only gotten five pictures. Normally, I have to take about 20 to 40 pictures to get a few that show the details I want to see, so I didn’t get anywhere near as many as I would have liked this time. Without pictures of the eyes, it’s only a guess that it is an “antlike jumping spider”, subfamily Synagelinae. On the plus side, it did confirm that it had pretty substantial jumping abilities, so some species of jumping spider seems pretty likely.

I gather that there are two reasons for spiders to mimic ants. The obvious one is to convince predators that can’t really deal with ants that they won’t be able to deal with the spiders, either, and so leave them alone. The other reason is a bit more insidious: if the ants buy the mimicry, then the spider can sneak up on unsuspecting ants and pounce on them while the ant thinks that they are another nestmate. This usually requires that the spider also emit some scent cues so that they will “smell right”. If it does this well enough, it might even be able to sneak into the nest and feast heartily. I don’t know if this one is a good enough mimic to fool the ants, though. It might just be getting by with giving predators the idea that it’s more dangerous than it actually is, and leaving the ants alone. I’ll have to seriously watch some of our Formica nests to see if there are any ant-mimic spiders hanging around them.

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[1] I bicycle to and from work once the show melts, but the last half-mile to our house is really steep (it’s one of those hills that has signs saying “Trucks Use Low Gear”, and I think it’s a 12% grade in some spots). I can ride the bike up the hill, but it wipes me out. So, I push it up, which means I am walking slowly up the hill leaning forward, and can easily scan the paved shoulder to look for interesting critters.

[2] Although, as ant-mimic spiders go, this one isn’t anywhere near as impressive as some others. The one that gets me is this one, where the male spiders actually have turned their mouthparts into a second fake ant, so they are mimicking an ant carrying another ant.

They look kind of beetle-like, but they are actually in the family Corixidae, which are included in the Heteroptera, or “true bugs”. There are a bunch of species of water boatmen, but it isn’t realistic to try to distinguish them down below the family level, because they all look the same: head with big eyes, streamlined body, and the two hind legs elongated into “oars” for swimming. They aren’t all that fast overall, but when they paddle with those oars, their motions are so jerky, and they are so able to dart off in random directions, that they are somewhat hard to catch[1]

I’m not quite sure what their mouthparts look like. If they are like other true bugs, they would have a “beak” for piercing and sucking, but water boatmen are reported to eat algae and small plankton, which sounds more like the sort of thing that you need to either chew up or lick up. Their front legs are modified to have little scoops on the ends, which look like they are suited for sweeping up tiny floating things in the water:

This is one of the features that distinguishes them from another type of small aquatic bug: the “backswimmers”. Backswimmers are about the same size and shape, and have the same sort of elongated legs with oars on the ends, but (a) backswimmers are predatory, so their front legs are designed for grabbing things and don’t have the little scoops; (b) backswimmers swim upside down, while water boatmen swim right side up; and (c) backswimmers can bite you if they are handled roughly, while water boatmen are harmless. You probably don’t want to use that last item for identification if you can help it, though.

Unlike the other aquatic insects that I’ve found so far, water boatmen actually breathe air. They trap an air bubble under their abdomen and can breathe with this air bubble for some time. If you look at the first picture, you can see the fringe of little hairs sticking out from the back of his abdomen that help to hold the air bubble underneath.

There is a big bonus from breathing air instead of water: oxygen is not very soluble in water, and so even well-aerated water doesn’t supply all that much oxygen. Grabbing an air bubble from the surface not only privides oxygen at much higher concentrations, it also allows the water boatman to live in water that is kind of stagnant and oxygen-poor.

Some species of water boatmen can also make noises, kind of like a cricket, that they can use to call mates through the water. They sound like this.

They aren’t really committed to the whole aquatic lifestyle, this one was perfectly happy to climb up out of the water and onto the side of the dish:

And, somewhat unusually, they can actually fly directly from the surface of the water. In fact, they can evidently shoot up from underwater, pop through the surface, and fly away[2]! This is not something a lot of insects can do, usually they have to haul themselves out of the water before they can spread their wings and fly off.  One of the things that lets them do this is that their sufaces are highly water-repellent.  The one in the picture above just crawled out of the water a few seconds before the picture was taken, and I can’t see even a single water droplet or moist patch anywhere on it.  That’s how completely it shed water.

——
[1] We caught this one by quickly sinking a large container right behind it. The sudden inrush of water sucked it right into the container. Voila! I think if we’d tried putting a jar over it, or netting it, it would have gotten away, or at least taken a lot longer to catch.

[2] Like Supercar!

OK, so this is clearly something in the order Orthoptera - grasshoppers, katydids and crickets. Here’s an opportunity to use this great book that I just got a few weeks ago: The Orthoptera of Michigan[1]. It only took a minute or two to sort out that it’s a “Camel Cricket”, genus Ceuthophilus. The winglessness, humped back, long legs, and very long antennae made it pretty easy to make the match.

The antennae are very long, I had to take a long shot in order to get them all in. I’d say they are easily twice the length of the body:

It looks to have an ovipositor, so I’d say it is most likely a female. It looks like the males have significantly shorter abdomens in most species. She’s got some pretty pronounced spines on the hind legs, too, which look like they’d be a problem for anything that wanted to eat her[2]:

So, anyway, this isn’t the type of cricket we usually see, normally we get the jet-black field crickets that chirp by rubbing their wings together. This one has no wings, so obviously isn’t going to do much chirping.  The long legs seem to help it jump a long way (it could jump almost 2 feet in the air), but it seemed to have a long cycle time between jumps, so it was relatively easy to catch it.  In comparison, the comparatively short-legged field crickets only jump a few inches at a time, but they can jump every second or so, which actually makes them a bit harder for me to catch.

Camel crickets eat pretty much anything organic they find, and like to hang out in protected places like the undersides of logs, under rocks, leaf litter, caves, and (obviously) basements. They like a bit of moisture, so they do well in a somewhat damp environment, and they evidently like things a bit on the cool side.

Orthoptera of Michigan  gives a few methods for catching crickets on purpose, as opposed to just grabbing them as the opportunity arises: (1) leave a small pile of dry oatmeal in the woods to attract foragers, and check on it very early in the morning; (2) find a bare spot on the ground, and prop up a board over it so that crickets looking for a hideout will crawl under it; (3) make a pitfall trap from a cup buried up to its top in the ground, with molasses in the bottom for bait; and (4) smear treetrunks with molasses. It sounds like these methods will probably attract quite a variety of small crawling things, not just crickets. I need to try a few of them this summer.

————
[1] By Roger G. Bland, Published in 2003 by Michigan State University, Extension Bulletin E-2815. It has color photographs and everything, along with full-blown identification keys. I love these guides that are specific to the region where I am - the region-specificity really weeds out a lot of extraneous possibilities, allowing me to focus right in on the relevant stuff. Most insect guides for North America seem to have about 90% of their entries consisting of things from Florida, Texas, or California that wouldn’t be caught dead this far north. The MSU Cooperative Exension Service has a lot of really good local guides: I have the ones for butterflies, grasshoppers, snakes, turtles, amphibians, and Insects of the Great Lakes Region.

[2] “Do not try to eat the large grasshopper legs, as they have barbs that may stick in your throat.” (from the U.S. Army Survival Manual, FM 21-76, page 1 of chapter 7, “Wildlife for Food”). Sounds like good advice to me!

These are “Water Lice”, genus Asellus. They are isopod crustaceans closely related to “wood lice” like Armadillidium and Porcellio, except that they are aquatic. They still live under rocks and branches a lot of the time, and eat stuff like fungus and decaying leaves. They just do it under water instead of on dry land.

I wanted to get a picture of the underside, and eventually I got the bigger one flipped over without having it flip right back again

This looked odd - there were too many legs. Something was on the underside. It took some time and a lot of pictures, but eventually I got a good clear shot of what was going on under there:

There was another, smaller water louse being held underneath! The big one is evidently a male, and he’s guarding a female so that he can mate with her on her next molt. It looks like he’s devoting one pair of legs to holding her, and then just proceeding with life as if nothing is going on. I expect that she picks up a lot of food from the debris that he stirs up as he eats.

There is apparently a tradeoff going on here regarding the size of the females: larger females can lay more eggs and would therefore seem to be more desirable mates, but the smaller females are easier to guard, and are less likely to be “poached” by other males. This one, for example, is so much smaller than the male that it’s hard to tell she is even there, so he has her pretty much all to himself. So, next time she molts, he’ll mate with her, and then she will carry the eggs in an internal pouch until they hatch.

Water lice are reported to be easy to raise in aquariums, or even in a shallow dish. I bet they are at least as much fun as “sea monkeys”, and a lot cheaper to come by.

———–
[1] For anyone who doesn’t live where there are smelt, they are little fish, about 3-6 inches long, that swim up little creeks to spawn in the early spring. During a good smelt run, you can scoop them out of the stream with a net by dozens. They are very tasty little fish, they don’t have noticeable scales, and the bones are soft enough that you don’t even notice them when you eat them. All you need to do is cut off the heads, remove the entrails, and fry the fish up. Mmm, calcium. Well, technically, you don’t *have* to cut off the heads and remove the entrails, but most people are a bit squeamish about that.

[2] Cole’s Creek is actually kind of barren compared to our little stream. It has a mostly sandy bottom and a pretty fast current, and turning over any given rock in it exposes maybe two or three crawling things, instead of dozens or hundreds like what we see in our stream. I think that the sandy bottom doesn’t give a lot of shelter against the current, so the little arthropods get swept out into the lake instead of hanging around in the stream. Plus, Cole’s Creek obviously has fish, which snap up anything they find exposed. The bugs are there, they just aren’t present in any serious quantities.

So we captured several of them in jars and brought them home where we could take better pictures[3][4]. We had two distinct types of specimens: a larger one that had full-sized, functional wings:

and smaller ones with stubby wings that looked totally inadequate for flight:

These are Winter Stoneflies, order Plecoptera[6], family Taeniopterygidae. This is yet another order of insects where the nymphs are fully aquatic, while the adults are a terrestrial form and usually have wings. Stoneflies in general may transform to adults at pretty much any time of year, but the winter stoneflies specifically come out as soon as the rivers open up, and mate/lay eggs before most of the predators either emerge from whatever form that the overwintered as, or migrate back into the area. They have a habit of sunning themselves on railings, trees, and rocks near streams, warming up enough that they can seek out mates and (if winged) fly off and disperse to lay eggs. I expect that the winter stoneflies are jet-black specifically so that they can absorb heat from the sun as quickly as possible. The nymphs are “shredders”, eating bits of decaying plant matter in the water, pretty much like the caddisflies and the amphipods from the last two weeks. There seems to be a lot of that going around, probably because in streams, bits of decaying plant matter are the most common food source and so anything that eats it can become very plentiful.

I’m pretty sure that the specimens I have pictures of here are at least two species (one flying, one non-flying), maybe three (the two with non-functional wings have different body/wing length ratios, but this could either be because they are different species, or because this is the normal range of variation for one species. Maybe one is male and the other female). There is probably a bit of advantage for the non-flying forms, they seemed more active and more numerous than the winged form. Insects evidently have to warm up their flight muscles to quite a high temperature before they can fly, so forms that spend a lot of time in cold conditions probably don’t get a lot of benefit from the wings. The non-flying forms can therefore spend a lot more time mating and laying eggs, and less time sitting around sunning themselves to get warm enough to make their wings work.

————
[1] That didn’t last. Less than a week later, we got a blizzard that dumped about a foot of snow on us. Will winter never end?

[2] It hadn’t. The boardwalks still had over a foot of kind of slushy snow on them, so we just went down to the pedestrial/bicycle/snowmobile bridge to watch the water rush underneath.

[3] OK, this is another set that bends the rules a bit. They weren’t captured on the property, but I would not be at all surprised to find them here, since they could easily live in the same little stream that the gammarus and the caddisflies live in.

[4] All of these were really hard to photograph, because they have the standard problem of all the cold-tolerant species: once they get into a warm house, they overheat and go into a sort of frantic overdrive mode where they scurry, scurry, scurry and refuse to sit still for anything. For the large winged one, I ultimately ended up putting some snow with it in the petri dish and putting a glass cover slip over it to keep it from escaping. For the smaller ones, I made an insert out of plastic[5] to hold the cover slip in place and sealed, and then refrigerated the whole works so that they’d be properly cooled.

[5] The problem I’ve been having is that the cover slip I have isn’t quite as wide as the petri dish, so it leaves a gap on one side that scurrying critters insist on crawling through. Putting snow in the dish made it possible to mound up material on one side to close off the gap, which helped a lot for keeping the stonefly from escaping. So, I made a plastic insert out of Shapelock, a special plastic that softens in hot water so that it can be molded like modeling clay until it cools off. Once it cools, it gets pretty rigid and looks and feels like high-density polyethylene. It’s great stuff, I bought a pound of it a while back and have used it for all sorts of fiddly little things where I needed to make a strong small part quickly. A pound goes quite a long way, too, I’ve still got over 3/4 of the container left. So now, I can not only put the glass cover on the petri dish without leaving a gap, but the plastic also has a lot of heat capacity, so if it is chilled in the refrigerator it works to keep these cold-tolerant insects cool enough that they slow down and act normal. I wish now I’d done this for the snow fly a while back.

[6] In the last three postings, I just added three arthropod orders (amphipodia, trichoptera, and plecoptera), increasing the number of orders that I have entries for by over 20%. All because of grabbing specimens from streams, an environment that I hadn’t been photographing much before now.

So, while we were capturing the Gammarus for last week’s entry, we scooped up some water from the stream into a jar to put them in. In the process, since the stream was so shallow, we got some debris off of the bottom into the jar, too. Then, when we got it back to the house and started looking at what we had, S_ noticed that one of the bits of debris was oddly symmetrical and had a hole in one end[1]. So, we put it into the petri dish along with the amphipods, and waited to see if anything came out. Something did:

This is a caddisfly nymph, order Trichoptera. Given that we are in the north, it’s likely to be a Northern Caddisfly, family Limnephilidae. Caddisflies have aquatic nymphs, and most caddisfly species build these protective tubes around their bodies out of bits of debris glued together with silk. This one built its tube out of sand. Apparently most species have a characteristic material that they use for their armor, other species might use bits of wood, snail shell fragments, or a simple case made out of silk.

I was photographing this one while the Gammarus were swirling briskly about, and after a while one rammed into the caddisfly and rolled it over[2], so I could see the underside:

The poor caddisfly couldn’t roll back over, because the tube had a more or less square cross-section and was flat on the back, so I got to keep photographing while it lay there, waving its little feet impotently in the water:

The feet look to me like they are adapted to hang onto a rock or stick while the current flows past carrying food. The tube-building caddisflies are “shredders”, they catch bits of organic debris to eat (they basically have the same diet as the Gammarus amphipods do, so it is not too surprising that we found them in the same place). There are also some predatory species that don’t build cases, but this isn’t one of them. Once they mature, the nymphs molt to produce a winged adult that looks a bit like a small moth, which flies off to eat nectar or plant juices, mate, lay eggs, and die.

———
[1] The fact that we caught this one completely by accident suggests pretty strongly that our little stream is absolutely lousy with caddisfly nymphs. Next time we go down, I’m just going to shovel some sediment into a jar at random and see what we turn up.

[2] “Gammarus versus the Caddisfly” sounds like a Japanese monster movie. Just imagine these being about 60 feet tall and fighting it out in Tokyo.

Last Sunday, it was pretty warm, and S_ suggested that it would be a good day to take Sam down to the stream[1] to turn over some rocks to see what was underneath[2]. So, I grabbed this rock that was in the middle of the stream, turned it over, and found about 20 of these clinging to the bottom:

This was a surprise. I’ve turned over a lot of rocks in streams before, and never seen anything like this. It turned out that the most straightforward way to photograph them was to put some water in the petri dish that I normally use, put three of them in, and just let them swim around. And they did swim around — they zoomed around in circles pretty much without a break. Every now and then, one would stop long enough for a photograph, but then one or both of the others would pile into it and they’d be off again.

Given how much they looked like shrimp, it was pretty obvious that they were some type of crustacean. It was clear that Bug Guide wasn’t going to be any help, because they explicitly exclude fully-aquatic non-insect arthropods, so they’ve got nothing.

S_ did a bit of rummaging around, and found out that they were freshwater amphipods, in the genus Gammarus[3], also commonly known as “scuds”.
They are frequently mistaken for shrimp, but shrimp are a different crustacean order (shrimp are decapods, not amphipods).

For something that lives under rocks and comes out at night, they have reasonably well-developed compound eyes (you should be able to see the individual cells of the compound eyes here)

You can also see the bases of the antennae here. Unlike insects, which have two antennae, crustaceans evidently have four. The function is similar (smell, taste, touch), the crustaceans simply have more of their head appendages devoted to the task.

Gammarus[4] are detrivores. They eat small bits of organic debris - decaying plants, algae, fungus, animals smaller than themselves, each others’ corpses . . . pretty much anything they can get into their mouths. They have a set of legs on their abdomen that never seem to stop moving, they just keep paddling along, sweeping water along the underside of their bodies, and grab anything edible that flows past. They don’t really seem to swim much up in the open water, they are more likely to scoot rapidly along the bottom while lying on their sides. They evidently need well-oxygenated water (which generally means cold water, because cold water dissolves more oxygen than warm water), and do poorly if there are any pollutants present. They are doing really well in our little stream, so I’d say our water is probably pretty unpolluted.

These guys look so very shrimpy, that I keep thinking that it’s too bad they aren’t bigger - about 2 inches long would be big enough to peel and eat. I bet they’d be pretty tasty if they were, say, steamed, peeled, and dipped in melted butter. Mmmm. Butter. Maybe I could selectively breed them to be bigger. A lot bigger.

They are also sharing the stream with a lot of other little aquatic arthropods, I’ll have pictures of one of their neighbors next week.
———
[1] Just off the NE corner of our house, there is a small year-round spring that produces a continuous stream of water. Technically, this could be considered a “creek”, even though at the points where it has a well-defined channel, it is maybe 6 inches wide and 3 inches deep, and runs maybe 200 feet from the spring to the drainage ditch by the road. It’s too small for fish, but it is a paradise for small aquatic arthropods.

[2] Getting to the creek is much more of an undertaking than it sounds like. Even though it is only about 50 feet from the house, the direct route there involves getting through a barrier of brush and Virginia Creeper vines while descending down a very steep slope with a drop of about 10 feet. At this time of year, there is also still about 3 feet of snow on the slope, because it is protected from direct sunlight and takes a long time to melt. Then, once at the bottom, it is unwise to stand in one spot for very long, because right beside the spring is a patch of very sticky, clayey muck that your feet gradually sink into. It’s a good place to lose boots. It is much easier to get out by following the stream all the way to the road, and then walking up the road back to the house, which is probably 10 times further than the direct route but far easier walking.

[3] Oddly, for these beasts the best sites to find pictures are not pages written by biologists, but rather pages written by fishermen. Gammarus evidently makes very good fish bait, you can buy them commercially. I gather that they are also popular in aquariums, and it looks like dried Gammarus pellets are a good food supplement for pet turtles (it keeps their shells from getting soft).

[4] I keep looking at this name and thinking of “Gamera”, the giant Japanese monster turtle that flies by pulling in its legs and shooting out jets of flame.

She’s got pretty hairy legs for a crab spider, so she’s probably in the genus Misumenops.

Incidentally, while it is usually possible to tell a crab spider by their shape and stance (laying flat, with elongated front legs held in front ready to snatch things), the way to *really* tell them from other spiders is their eyes. They are arranged like this:

If you ever go through a spider identification key, the jargon that the arachnologists use for the eyes is:

AME (Anterior Median Eyes) - the two eyes in the front center
PME (Posterior Median Eyes) - the two eyes in the back center
ALE (Anterior Lateral Eyes) - the two front eyes that point to the sides
PLE (Posterior Lateral Eyes) - the two rear eyes that point to the sides.

Arachnologists like to use the sizes and shapes of the eyes for identifying spiders because that is something that tends to stay very similar between closely related spiders. It is evidently very easy for spiders to evolve different coloration patterns and even changes in their body shapes, but evolving a new eye distribution or resizing the eyes takes a lot more generations. So, the species in a given family will all tend to have the same eye pattern. The unfortunate part of this is that you really can’t make out the eyes without magnification, and sometimes not even with magnification. So, for a quick ID of a spider that is rapidly scurrying behind the refrigerator, the eye pattern doesn’t really help much.

Anyway, the crab spiders all have this fairly characteristic arrangement of eyes: two sweeping curves running around the front of the face, with all the eyes about the same size and pretty much equally spaced along the curves.

As for how they hunt, spiders in this genus typically hang out in flowers and wait for some pollinator to come by. Then, as David Brady so eloquently put it, they bite it in the face. This unfortunately means that crab spiders aren’t as beneficial to us as other spiders, because instead of mostly eating pest species, they eat pollinators. Luckily, they don’t really get plentiful enough to make a serious dent in the pollinator population, so our crops still get pollinated. There’s no real need to worry about crab spiders.

———-
This spider is still from last summer, but it is probably the last of my “backlog” bugs that I’ll be posting for a while. Why? Because the spring flush of insects is on! We found a bunch of “winter stoneflies” yesterday (they were being stalked by tiny spiders), and there are caterpillars coming out of hibernation and new insects in the house that haven’t been seen all winter. Time to get cracking, these bugs won’t photograph themselves!

You might note that it has a reddish-orange stripe down the back where the wing covers come together. It is most likely a Buffalo Carpet Beetle[2], Anthrenus scrophulariae. I think it is interesting that the coloration is in scales on the surface of the wing covers, not embedded in the wing covers themselves. This is the same sort of thing we saw with the Larder Beetle in an earlier posting, except that the larder beetle was covered with short, colored hairs instead of scales.

There seems to be a bit of a rash of carpet beetles appearing on people’s blogs this month: there’s some pretty recent pictures at Insect Picture of the Day, and Wanderin’ Weeta[3]. These are both a different species from what I have here, they are probably Anthrenus verbasci, the “Varied Carpet Beetle”.

Here’s a picture of the underside of the beetle [4], for good measure

Something that Wanderin’ Weeta pointed out is that there are slight depressions on the beetle underside that the legs can socket into, making a nearly flat surface. I expect that this is so that, when the beetle is getting knocked around (as commonly happens to beetles), the legs can be pulled out of harm’s way rather than getting snapped off.

I’ve already talked about the lifestyle and eating habits of dermestids in earlier entries, so there’s no need to dwell on it now. I would like to mention again, though, that they are pretty much endemic in everybody’s houses. You may have lots, or you may have only a few, but unless you periodically purge and sterilize your house and everything in it, it’s a pretty safe bet that you’ve got ‘em. People talk about cockroaches being inevitable, but really, we don’t seem to have cockroaches at all this far north[5]. We certainly have carpet beetles, though.

———
[1] This is another “Extended Depth of Field” picture, with the back, sides, legs, and antennae all in pretty good focus. As I had hoped, EDF works a lot better for blocky opaque insects than for insects with long, transparent appendages.

[2] S_ says, “Does this mean it’s from Buffalo, or that it looks like a buffalo?” To which I say, “Beats me, maybe it likes to live in buffalo-skin rugs”. Could be any of those, I guess.

[3] Comparing their pictures to mine gives a good chance to see how much benefit I’m getting from the improvised macro lens made from a reversed SLR lens. David Brady (Insect Picture of the Day) uses a camera similar to mine (his is a Canon Powershot A640, I’m using an A95). I think that Wanderin’ Weeta is using a Canon A720 IS (another model in the same series, but with almost twice as much optical zoom as mine has). At any rate, we are probably all using cameras with broadly similar native optics to photograph essentially the same insect. The cameras with no supplementary macro lens, running only on their native macro mode, can get pictures that are good enough for identification of critters 2-3 mm long. But, there is a significant amount of blurring that is hazing out the details that are brought out using the macro lens. I’d say that the carpet beetles are about the smallest things that can be photographed decently with a stock consumer-grade camera, and a specialized macro lens gives pretty significant improvements at this size and smaller.

[4] This one isn’t EDF, unfortunately. The beetle was unhappy about being upside down, and insisted on waving his legs around vigorously the whole time. So, I couldn’t get the necessary series of photos at different focal depths.

[5] Seriously, it’s true. I’ve seen cockroaches in southerly areas[6], so I know what they look like, but I’ve never seen one here in the Keeweenaw. I’m told that they crop up from time to time in the dorms at the university when they ride in on people’s luggage, but they don’t last. We don’t seem to have house centipedes to any great extent, either - I remember one occasion where a friend found a house centipede that she killed by spraying with Chanel No. 5 (I think)[7], but that’s it.

[6] Once, when I was a graduate student, I went to Phoenix, AZ for a technical conference. I didn’t have much money, so instead of renting a room at one of the conference hotels, I just flew into the city blind, got to the conference center, and circled around on foot until I found a cheap place that had a room. The “Coronado” was $70 a week, and had one room available, so I took it (even though the manager looked at me as if I were insane). I noticed that there were little black objects all over the walls, in varying sizes. On closer inspection, they were moving, and on still closer inspection, they were cockroaches. Well, I had never really seen cockroaches before, so I was fascinated with them. And I figured, well, to get an otherwise reasonably spacious hotel room at one-seventh the then-going rate for a room in a roachless hotel, one just has to put up with something, so I shrugged and went to bed.

The next morning, I got up, and stepped into the bathroom - and felt something moving under my foot. I quickly lifted my foot, and saw this monster cockroach the size of the palm of my hand scurry off and hide behind the toilet. Whoa! After that, I was more careful to watch where I stepped. Later on, when I was walking around town, I saw another one of these giant roaches - it had been run over by a car, but was still perfectly recognizable.

Finally, when the conference was over, I called a taxi to pick me up and take me to the airport. The driver seemed apprehensive at first, until he found out that I was only a naive graduate student, and not some sort of criminal. It seems that the only people who normally went to that hotel were drug dealers and prostitutes, and I was lucky to get a taxi to come there to pick me up at all. Which explains the look the manager gave me when I checked in. Huh. Go figure.

[7] It was some sort of perfume, at any rate. I think it was that one, but I’m no judge of perfumes. Once, I was at a restaurant with some friends, and noticed a smell that I thought was Muskol Insect Repellent (it certainly smelled like DEET to me, anyway). This was the middle of the winter, an odd time to be wearing insect repellent, so I asked about it. Turns out it was Chanel #5[8]. The friend wearing it was not amused. Yes, I’m probably an unsophisticated boor with no taste for the finer things. I’ve learned to live with it.

[8] OK, now that’s just weird: In the Wikipedia article on Chanel No. 5, it says this:

“Chanel applied the French aesthetic theory that “ugly” placed next to “beautiful”, by contrast, makes the beautiful object appear more so. In this era almost all perfumes were floral and “pretty” - designed to enhance a woman’s beauty with more beauty. Instead of the scent of flowers, Coco wanted a perfume that “reflects my personality, something abstract and unique”. She believed that a perfume should serve to spotlight a woman’s natural beauty using contrast - i.e. the artificial perfume would make the woman’s natural beauty more evident.”

If I’m reading this right, this means that Chanel wanted it to smell kind of nasty and chemical-y! So, maybe it does smell like DEET!

The very long ovipositor (in this case, longer than her body!) is pretty characteristic. While it looks dangerous, it isn’t a stinger and she’s harmless (to us! More on this later . . .) - the ovipositor is used for laying eggs in awkward places.

While it is certainly a member of the Superfamily Ichneumonoidea, Bug Guide isn’t a lot of help beyond that. It could be one of the Family Ichneumonidae, the “true” Ichneumon wasps (about 3100 species in North America), or one of the related Family Braconidae, the Braconid wasps (about 1700 species in North America). The thing is, both the Braconid family and the Ichneumon family are highly variable, and there are a lot of Braconids and Ichneumons that look a lot like each other.

To tell whether it is a Braconid or an Ichneumon, we have to look at the pattern of veins in the wings. It took a little doing to find a good wing picture[1], but this one is not too bad:

And, if we compare it with this drawing[2]

we can see that the vein layout matches the Ichneumon pattern. Specifically, Vein 2m-cu is present, if it was a braconid wasp, this vein would be missing.

Well, enough about trying to identify it. The big question is how do they live, and what is that loooong ovipositor for? This brings us to the singular habits of wasps[3].

Ichneumon wasps are all parasites of other small creatures, usually larvae of one type or another. They lay their eggs on, near, or in their victims, and once the eggs hatch they gradually eat their way around inside, delaying eating any of the really vital organs of their tormented host until they are ready to pupate[6]. At that point, they usually (finally!) kill the host, pupate on or in the corpse, and then emerge as adults.

I gather that their parasitic lifestyle is why there are so many species of Ichneumon and Braconid wasps: some of them are general parasites of many species, while others are highly specific parasites of just one or two host species. Braconids in general are usually smaller than most Ichneumons, with the Braconids tending to parasitize smaller insects, like aphids[4]. So right away, we get different species depending on how big the host is.

Then, there is the question of host lifestyle: the wasps have wild variations in the ovipositor design, depending on how they have to lay their eggs in order to get them into the hosts. Some of them land directly on the host and plant an egg in them, in which case the ovipositor is relatively short and designed for a quick inject-and-go style. The ones with very long, robust ovipositors, like this one, are more likely to use them to penetrate rotting wood, laying their eggs in the grubs tunneling around under the bark. They walk around on the surface of the wood, listening for vibrations of grubs moving around. Then, when they find one, they pinpoint it, and quickly bore down through the wood and get the eggs as close to the (now doomed) target as they can. There’s some question about how they bore through the wood, they evidently don’t have an obvious wood-boring mechanism on the ovipositor tip[5].

Finally, there’s the question of host immune systems. If, say, a caterpillar’s immune system is up to snuff, it can reject the wasp egg, so the wasp has to be able to counter the immune response. This is where it starts getting weird: it seems that the braconids and ichneumons have symbiotic viruses that they inject into the host along with the egg, and the virus suppresses the host immune system so that the egg can grow. The thing is, the virus actually grows in the wasp (it has been inserted into the wasp genes), so the wasp larva that hatches out already has the virus in itself, so when it grows up it will have the virus to inject into the next host. This whole thing really drives the wasps to be different species, because they can only lay eggs in a host that will have its immune system suppressed by their particular strain of virus. So, we pretty much have every host species with its own species of parasitic wasp to infect it, and voila! Thousands of specialized species of wasp!

And, one last, almost unrelated note:
When I searched for “ichneumon”, this bit came up on Wikipedia — “The ichneumon is the enemy of the dragon. When it sees a dragon, the ichneumon covers itself with mud, and closing its nostrils with its tail, attacks and kills the dragon. The ichneumon was also considered by some to be the enemy of the crocodile and the asp, and attack them in the same way.” That’s evidently based on something Pliny the Elder wrote. Of course, it turns out he was talking about the Egyptian Mongoose (which is also called an Ichneumon), and this is a garbled version of how the real animal kills snakes. What the connection is between the Ichneumon mongoose and the Ichneumon wasp, I really can’t say.

—-
[1] While this wasp wasn’t all that big in terms of mass, it was awfully long, so I was photographing it without the macro lens so I could get the whole insect into a single frame. Now, many months later, I think that was a mistake, I really needed the macro in order to see the wing veins properly. These days, I think I’d go ahead and take detail pictures with the macro in addition to a “long shot” to get the whole wasp.

[2] The drawing is from this document (**Warning! Huge PDF file that takes forever to download!**), which is a key for distinguishing between the subfamilies of ichneumons and braconids. Unfortunately, it is for the ones found in England, so it misses a lot of the ones in North America.

[3] “The Singular Habits of Wasps” is the title of a story by Geoffrey A. Landis that involves Sherlock Holmes, Jack the Ripper, aliens, and parasitic wasps (with a brief cameo by H. G. Wells). It is in Landis’ collection Impact Parameter for anyone who wants to read it.

[4] The size difference isn’t a reliable way to tell them apart, though. The smallest Ichneumons are smaller than the largest Braconids. Also, the parasitizing evidently doesn’t stop with the first wasp: if you read to the bottom of this page, you can read about another kind of wasp that lays eggs in the wasps that parasitize the aphids!

[5] If I catch another one this spring, maybe I can mount it up and sign up for some electron microscope time at work, so I can look at the ovipositor tip under very high magnification.

[6] Darwin was evidently particularly repulsed by these wasps. He wrote the following in a letter: “I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars, or that a cat should play with mice.”