Tuesday, December 31, 2013

Winter invertebrates

It is officially winter, the Northern Hemisphere has had its shortest day/longest night, and now our days will begin lengthening.  Our good friends who live in northern Sweden have just written to us that by ten-thirty in the morning it is light enough to be able to identify a bird on their feeder, and at two the sun sets again. And I know when the sun is up it is not UP, it is just above the horizon and crawls along almost parallel to the ground, barely clearing the trees, until it sets.

We can't very well complain about light deprivation here: The sun now is coming up at seven, and setting about five.  Nevertheless for someone who wants to study and photograph insects and other invertebrates, this is a severe downtime, since the cold-blooded creatures for the most part have gone into hiatus in some hibernating form--egg, larva, pupa, or, more rarely, adult. In some years in Arkansas I have seen shirt-sleeve weather in December, with a few butterflies and dragonflies still active, but this year we have already had a period of weeks with a solid sheet of ice on the ground, with the temperature at our house coming above freezing only long enough for a three-inch rain, and then going back into freezing temperatures most nights. Days are sometimes gloomy, but sometimes clear and still, with our beautiful winter sunrises, an orange ball rising from a slightly misty row-crop field. That's worth something, I have to admit, especially when it is complemented in the evening by an equal moonrise.

This is our backyard pond iced-over in winter. In summer it is so crowded with aquatic plants you can't see the surface of the water.

Well, I thought I would go out on days when it rose above freezing to see what invertebrates I could find. There are some winter specialists that endure the discomforts in order to avoid the competition of a more crowded season. There is, for instance, a moth that only comes out in the depth of winter. On several occasions in past winters we have been driving at night in light snowfalls and noticed that the snow flakes in the beam of the headlights were not all spiraling down; some were flying up. It was these moths, even in that kind of weather. (We have seen a few out this winter, but not managed to get a photograph.) The idea, as I understand it, is that there are no bats, their most serious aerial predators, around in winter. There also is no suitable food for them, but in fact many moths have no mouth parts and do not feed anyway. They get by on fat stored up in their larval form. It also is not warm, thought to be essential for all cold-blooded creatures, but certain insects find their way around that as well. Bernd Heinrich, my favorite biologist/writer, has demonstrated that many insects are in fact warm-blooded, using shivering and muscle contractions to create an inner temperature well above ambient. The major part of a moth's life is as a caterpillar. At the end of that period, it becomes a pupa, then emerges essentially as flying genitalia. It flies briefly, trots its stuff, mates, lays its eggs, and it has done its work and created a new generation of caterpillars. The winter moth does this in a less complicated world.

We knew about the moths, but what else is out?

There are spiders. I had in the past noticed spiders out, it seemed like, in all kinds of odd parts of the year. One reason I decided to study them seriously this past year is because it seemed like their season was much longer than that of most insects, and that would give my studies less winter down time. So I kept my eyes open, and on days when it warmed up to say the 40s I noticed small wolf spiders running through the leaf litter ahead of me as I walked. They were tiny, and kept moving, and often dived under the leaves, but with a little patience I got a picture of one, good enough to ID it.

It was a spiderling, not an adult, and it was tiny, perhaps 3-4 mm long (the adult is only about 5-6 mm) but I blew the photo way up and could see enough details for the identification. The right-angle long bristles on the legs told me it was in the genus Pardosa; the marking on the abdomen made it P. milvina. Not a surprise, this was the commonest spider around. It was the first spider I identified when I began my studies in March of this year, seeing them running on ahead of me as I walked through my yard, and I had seen them just about every day since then, and my guess is that they will end up being out in every month of the year. Now here is a problem: you see them by the thousands during the year, but almost never carrying prey, to the point where some biologists say they must be very inefficient hunters. Now, some (stingy?) biologist has demonstrated that they can live up to two years without eating. How can that possibly be? There is almost nothing to them to start with. And why do they keep on running, when almost every other invertebrate does a long pause during the coldest months? Mysteries.

Pardosa milvina comes out day and night, but many other wolf spiders come out only at night. I wondered, would a winter night op be feasible? December 28th it warmed up a bit, and an hour or so after dark it was still in the low 40s. I put on my head lamp and went out. There weren't a million eyes shining back at me as in summer, but there were SOME eyes shining back. It was mainly wolf spiders, as I had guessed it would be, but not all. The first spider I saw was a funnel-web spider (recognizable by its striped pattern and long spinnerets), not in a funnel web but out wandering around, doing whatever it is they do in winter. I had seen one earlier scavenging a dead insect, so perhaps that is something they do.

Farther along I found a half grown Nursery Web Spider (Pisaurina mira). This is another spider that is very common in the summer. They make no web, but sit on top of vegetation and wait for something to come close enough to grab. I have no idea what they do during the winter and was very surprised to see it out.

But it was the wolf spiders I saw the most of, perhaps some twenty lights reflected back at me. Most were peering out from under a cave of fallen leaves. When the leaves come down in the autumn they pile up to a depth of two or three inches in our yard, and they are so full of insect eggs and pupae that I don't rake them till spring when next year's growth is underway. That makes it harder to find and approach the wolf spiders, as they don't come very far into the open, and can disappear simply by stepping back.

What I guess most wolf spiders do is sit back in a burrow or a place like these leaves, and lie in wait to ambush whatever comes by. But what does come by in winter? I suppose other spiders. All of the wolf spiders I saw were of this one species. This one popped out far enough for me to identify it.

It was Gladicosa pulchra, one of the commonest wolf spiders, and I was beginning to put together a life history for it. In early spring I only found adults, and I found all of them on tree trunks close to the ground. (I read that at that season they were virtually always on the trees.) Their often elaborate patterns blended perfectly with the moss and bark, and I found this species in all my night ops. Later in summer I began to see them off the trees, running on the ground, and they were out in daytime as well, carrying all their babies on their backs. As summer went on, they became the commonest species to see in the leaf litter. Now it was winter, and they were still common, but now it was all half-grown individuals, the slightly grown up spiders that had been carried on the backs of their mothers in the summer. I had in fact read for this species that they spent the winter as immatures, so that they could become adult early in the spring to mate and lay their eggs, so their young would have a good start in the summer, a time of plenty.

But spiders in winter are not the only creatures around. There are also lots of flies, those tender creatures. I have more than once in past winters seen blue-bottle flies buzzing around actively in temperatures down to 28 or 29 degrees. They were the only invertebrates I had seen active in actually freezing weather. Probably they had some sort of antifreeze in their cells, and used the various ways insects used to maintain operating temperatures. But, I wondered, what are they doing out in winter? Then it occurred to me: blue-bottle flies feed largely on vertebrate carrion, and there is probably more carrion available during harsh and unforgiving winter than at other times.

On the 24th of December I thought I was seeing a blue-bottle out on a cold day, and I took a quick snap of it before it flew away. When I downloaded it I was quite surprised to see it was actually a Tachinid fly.

Tachinids are recognizable by the long spines on their abdomens (they are often called hedgehog flies because of them). They, along with Braconid wasps, are the great population controllers, keeping other insects from burying us under their exponential productivity. Adult Tachinids are a major component of the bees, wasps, butterflies, and other insects that crowd onto flowers in summer to drink nectar, and they are in fact valuable pollinators. But when they are not doing that, they are laying eggs on all manner of invertebrates which their larvae are parasitic on.

So what was this fly doing out in winter? I suppose it could be searching for caterpillars or cocoons that were overwintering, and lay eggs on them that would be ready to hatch in the spring. But then what? Their larvae would quickly finish eating their hosts, and, what? Wait as a pupa until next winter to come out and start another generation? That doesn't seem very sensible. It's another mystery.

There is one more species I want to talk about, that is always out in winter, and that is quite remarkable: The Winter Crane Fly. You could not have a more frail, a less durable appearing creature.

I have blown this picture up so you can see it more clearly, but this exaggerates it greatly. It is only about 5 mm long, which is to say, around a quarter of an inch. It is smaller and slighter than most species of mosquito. In fact, as I'm writing this, I have stepped outside my study and found one on the wall. This gives you a better sense of it:

Now, in bleak midwinter, if it warms up slightly, you may see a little smoke cloud of these tiny creatures whizzing around in a courtship swarm. Here is the best I could manage for a picture of it:

The Winter Crane Fly is called a crane fly, and looks like one, but it actually is only a relative to the crane flies. Here is a typical crane fly:

There are hundreds of kinds (480 species in North America) of these "daddy longlegs" in all sizes from quite large (three inch wingspan) to quite small. They are abundant here in spring and fall. Locally the larger ones are called Skeeter Hawks, under the folk notion that if they look like mosquitoes, but are much larger, they must feed on mosquitoes. Technically they are in the family Tipulidae, and their salient feature is that they have no ocelli. Flies and perhaps most insects have two large compound eyes, and on the forehead between those eyes, three simple eyes, or ocelli, usually arranged in a triangle. See, for example, this wasp:

Here is a detail from the crane fly above, showing its absence (is that a possible construction?) of ocelli:

All this is leading up to the fact that the Winter Crane Fly is in the family Trichoceridae, separate from the true crane flies because it DOES have ocelli. Now, I have known that fact for some time, but the Winter Crane Fly is so tiny that I have never been able to actually see the ocelli. So I got my camera with the 100 mm macro lens, and attached my extension ring to it to give me even closer focus, and got as close as I could to a Winter Crane Fly, and tried to take a picture that would show the ocelli when I blew it up on my computer screen. But the best picture I could get didn't show much of anything.

So I took desperate measures: I collected a specimen.

Herschel Raney and I collected hundreds of specimens of robber flies for vouchers when we were helping to create the state list of robber flies, however both of us would rather do things bloodlessly and take photos instead of specimens. But in this case I wanted to put a Winter Crane Fly under the microscope to look for its ocelli. The best way to kill an insect you want for a specimen is to put it in the freezer. A couple of years ago when I was working on grasshoppers and I needed a specimen to examine under the microscope, I put a grasshopper in a plastic container and put it in the freezer, and after some twenty minutes when I checked, it was dead and already so brittle that with the slightest touch one of its legs came off.

So, I caught a Winter Crane Fly, put it in a plastic container and put it in the freezer. After twenty minutes I took it out and looked at it, and it stood there looking back at me. Hmm. So I put it back in the freezer. Then I went in the house and Cheryl and I had our morning coffee and finished working a crossword puzzle, and I was given a list and drove into town to do some shopping, and by the time I got back two hours had passed since I put the fly in the freezer. I took it out and looked at it, and it stood there and looked back me.

Anyway, it was slowed down enough that I put it under the microscope, and even though it kept walking off and I had to reposition it, finally it stayed still long enough that Cheryl could use her little camera to take a shot of it through the microscope and finally get a rather poor view of one of the ocelli, which I guess would be an ocellus.

If you look at the little brown knob which is the base of the antenna closest to you, to the right of it and touching it you will see a tiny black dot. That's it, the only one of the three ocelli that is in view from that angle. As for the fly itself, I put it outside, and after a few minutes it flew off.

As for the fly's rationale: Coming out in winter, if it stays up on walls of the house where I find it, or up in vegetation, it will avoid the wolf spiders, and there is not much else around to predate it. As to where to lay its eggs, it's larvae feed on rotting fungi or decaying vegetable matter, and that's abundant and easy to find at any time of year. And how does it manage vigorous mating swarms in temperatures not much above freezing? Well, my accidental experiment suggests that it must be running on straight antifreeze (sugar/alcohol in the blood can produce it) backed up by wing-muscle warmup exercises.

Is it a good strategy, coming out in winter? Trichoceridae, the winter crane flies, are found not only here in the north temperate regions but in South America and Australia/New Zealand, suggesting the genus Trichocera has survived over an immense period of time, certainly from before the continents went their separate ways.

Wednesday, November 6, 2013

Is summer over already?

Well, I hope not. I go a long time through late winter and early spring waiting for summer to finally arrive. And then it's over in a minute, and I haven't got any of my projects finished. Especially a summer like this one, where it never got really hot, and never quite dried out. I thought one of the dependable things here in Arkansas was an almost endless balmy autumn, but here it is, barely into November, and all invertebrate wildlife seems to be closing down for the year.

I guess I'm in denial. It's a fact, the weather was never quite right for what I wanted, and we didn't travel around the state as much as I intended to, but these are my complaints every year. Some people are multi-taskers (actually, scientific studies tell us, multi-taskers are extremely rare, which is why we get nervous when we see the driver in the next lane texting). I personally am a single-tasker (one might almost say half-tasker), it's the only way I can operate.

When I retired around the turn of the century (that feels funny to say), in a happy convergence close-focusing binoculars and digital cameras and through-the-binoculars-type field guides to butterflies all came out at the same time.  I spent every minute for a couple of summers chasing and photographing butterflies, and then I started studying robber flies, those hairy alpha predators of the insect world, and I had to concentrate on them for several years, because there were no field guides. Finally, I ended up making my own field guide. Next a good guide to tiger beetles came out, and I closed my focus only to them for a summer, then it was caterpillars, then grasshoppers.

And suddenly Bradley's field guide, Common Spiders of North America, came out just as I was making plans for 2013, and when I saw the wonderful paintings in it by Steve Buchanan, I was converted in a single second. I've always loved spiders, but there was no practical way of identifying them. Then this book came out and very difficult ID problems were solved instantly by a glance at the right illustration. I got the book, put the tunnel around my eyes so that I was unable to see anything but spiders, and got to work. Except for a half dozen spiders that were my favorites from childhood on, I really knew very little about this remarkable group. The moment things started moving in the spring I was deluged. I had often read those statistics where so many thousand spiders are found per square yard of ground. Now I began to believe it.

I quickly discovered that a number of spiders were in that 2 to 4 mm size range, which meant they were impossible to really see. Now, I had decided I was going to try to observe them unrestrained, and unannoyed, to see them going about their natural business. I wasn't going to put them in plastic see-through tubs for close photography, and I certainly wasn't going to collect them as specimens, poor faded shriveled-up things in vials of alcohol. This of course made identification that much trickier. My modus was, when I saw a new spider (several daily, when I was beginning), I would try to get a very close-up photo in a position which revealed all its markings. Then I would blow up the photo on my computer screen, and get out the Bradley, and, when he didn't entirely solve it, search through BugGuide.

I love something that's completely new, where every day I am learning new things, starting from absolute scratch, a learning curve so steep I hardly knew where to begin. And, using my total immersion technique, I did learn. I'm astonished now to look at our Picasa Web albums and see that Cheryl and I have put together images (my big camera doing the straight ahead ones, her tiny camera reaching around corners or under leaves) of some 170 species, over a hundred species just in our own backyard. If I still can't remember all their Latin names, at least I am familiar with the look of them and the design of their webs if they are web spinners. There are species I especially want to see that I have missed so far, but there are many more species we found that I didn't dream we would.

Unless there are some surprises still waiting for us this year we have more or less seen the season around now, and have a good idea what to expect for next year. Our first goal is identification and distribution, but we are already moving on to behavior, which is so varied and imaginative, if you can say that about an animal with a brain the size of a grain of dust. An ultimate goal is to make a sort of illustrated field guide to Arkansas spiders, especially those found on Crowley's Ridge, that anomalous line of hills that rises out of the flat Mississippi Delta here in northeast Arkansas.

For now, here is our first draft (our summer's work), for anyone who might be interested. This will be a perpetual work in progress. We will boldly add new species as we find them, and quietly erase errors as we discover them or they are pointed out to us. What we have are four Picasa Web albums, in which the arrangement of species more or less follows the arrangement in Bradley, which is one of convenience,  since there is no agreed-upon evolutionary order.

The first album contains the Mygalomorphs, large long-lived "primitive" spiders like tarantulas; and Orb-shaped-Web Builders, very highly evolved species like the large garden spiders).

click here

The second album contains the Wolf Spiders, a large group of often striped spiders that don't make snare-webs, but run along the ground, catching their prey by pursuit or ambush. They are quite numerous, and many are nocturnal. If you go out at night with a headlamp on, you will see their eyes by the dozens shining back at you; and Fishing Spiders, species that often live on or even under water, and sometimes catch tadpoles and small fish.

click here

The third album contains the Jumping Spiders, another large group of often brightly colored spiders that don't spin snare-webs, but stalk their prey like cats until they are close enough to spring on them; and the Crab Spiders, some of which climb to flowers then change their color to match the flower's, so they can hide on it to ambush insects that come for nectar.

click here

The fourth album contains "all the rest," a  motley of ground hunters and primitive hackle-web weavers, such as the Feather-legged Spiders, Black Widows, Brown Recluses, and the strange Spitting Spiders.

click here

I shouldn't be too cavalier about our ability now to identify our local spiders. There are still some, especially from my favorite group, the Wolf Spiders, that we have a lot of trouble with. I have pictures that I change the name on almost every time I look at them. But that's great, that's the fun. In fact there are species that cannot be identified without dissection, but that's okay too. I want this to be a pictorial guide, so for now, I just want to get as close as I can visually.

Here's a footnote: Because we are concentrating so hard on finding spiders, we are seeing for the first time a number of species that have always been right in front of us.  We are also observing behavior we would never have dreamed of. For example, I had always assumed that spiders require fresh live food that they catch themselves. But last night (11/5/13) when I went out with my headlamp to see if any spiders would be out in 61 degree temperature (in fact, there were dozens of eyes glinting back at me) I came just inside my garage where I had noticed two or three days before a dead paper wasp lying on the concrete, and there was a funnel-web spider scavenging the corpse. I was amazed. In fact spiders have done something to amaze me almost every day this year. That's my idea of retirement, miles ahead of daytime TV!

Wednesday, September 25, 2013

Frogs, toads, spiders, bugs, and a Spiny Oak-slug

I commented on an earlier post that we were overrun with baby toads. They are still around, often turning up in the middle of a picture when you least expect them.

But there are distinctly fewer. I don't know if that is just because they have distributed themselves more widely throughout the neighborhood, or if something is predating them. Not many things eat toads. When attacked they squirt out poisonous juices. If a dog bites one once, it learns its lesson, and never bites another one; if you pick one up I hope you know to wash your hands before you touch your eyes. However the other day I caught a glimpse of something disappearing into cracks in the wood of our raised beds and realized it was a baby Hog-nosed Snake. Though only about a foot long it flared its head and did its best to resemble a cobra/puff adder, and I was reminded that this harmless (to us) snake is one of the few creatures who not only eat toads, but specialize in them.

So if they have actually reduced the numbers of toads in the yard, that might allow the wolf spiders a chance to rebuild their decimated populations, EXCEPT now the yard is overrun by frogs. They are always here in summer, but not in these numbers.  Bronze frogs and cricket frogs are lining the muddy edges of our pond, and green tree frogs are lined up on the stalks of the pickerel weed, or plastered against walls, or doing their droppings on all our windows.

The reason you see them out in plain sight clinging to the sides of walls or high up in the aquatic vegetation is that they too have a deadly enemy who hunts them ruthlessly and is, itself, a skilled climber: The Western Ribbon Snake.

This past weekend we were at Ferncliff Camp west of Little Rock, where we teach a class in insect ecology every year, and we did a night op there, out with our headlamps looking for wolf spiders, and just as in our yard, we hardly found a one (though we found some other very good spiders). This is our first year looking closely at spiders, and it can be that wolf spiders are very common in spring and early summer, then thin out when the hot weather comes, which is why we are not seeing so many now. We'll need to do this for another year, so we can get a pattern for a full year. Anyway, perhaps we were blaming the frogs and toads unfairly. Recently a big fishing spider (Dolomedes triton), has been sitting up in the middle of the pond vegetation, holding its egg nest in a sunny spot to speed development. This is a spider that skims over the surface of the water, that dives under water when disturbed, and is able to catch small tadpoles and fish. Dolomedes are usually common in the pond, but I had not seen a one this year, and thought they also were a victim of the frogs, skillful hunters of invertebrates. But obviously they had been there all the time, hidden in the thick vegetation. Frogs, toads, snakes, spiders are here every year. Their varied offenses and defenses must average out.

Now what else did I promise for this blog? Bugs. True bugs, in this case, of the order Hemiptera. Along with aphids and hoppers and stinkbugs, this includes Cicadas, which are still loud on hot days, but are beginning to wind down. At this time of year you begin finding dead or dying ones everywhere you look. But they are still very noisy during the day. This has been a big year for cicadas. The loud calling of course is the male's way to get the attention of the females. But it didn't occur to me that I have never, for some reason, observed cicadas mating, at least it hadn't occurred to me until I looked down at my feet one day and saw a two-headed cicada.

Fulgorids in the tropics are huge bugs with big sort of helmet-like structures over their heads. In this country there are a couple of dozen species but they are all puny things that look sort of like miniature cicadas, none of them more than 10 mm long. In late fall of 2007 we had turned on our porch light to attract moths, and when we checked there was a bug on the light that was somewhat like a small cicada but that we quickly worked out was a fulgorid. Only, it was 20 mm long. We sent it to BugGuide, and even Andy Hamilton, the expert on these creatures, was puzzled. The one we saw on the light was on the ground dead the next morning, plus we found a second dead in a spider web. We collected these and sent them off to Andy. He had identified them in BugGuide as Poblicia texana, but in a note added "Now that I have seen some specimens, it is my opinion that this is probably not the correct genus for this curious species--in some ways it looks more like the tropical genus Hypaepa."

In BugGuide now, there is a specimen from Mike Quinn from clear back in 1988, plus he submitted a nymph from 2010. Someone else has a Texas record from 2009, and there is a Georgia record from 2011.

We actually had another attracted to the same porch light in 2008, a year after our first one, but didn't report it to BugGuide. Yesterday I again found one on our porch, this one tangled up in spider-webbing. I untangled it and kept it overnight. It was fine when I released it. I guess we will report this one to BugGuide, since it is the third time on the same porch. Here are some pictures of it.

And now, the promised Spiny Oak-slug. If you have studied moth caterpillars at all, you will have learned that not all caterpillars look like caterpillars. There is a group called the "slug" caterpillars. Along with their slug-like shape, and the fact that they kind of ooze along the ground, they are heavily armed with toxic spines and often bright colors to warn you that you touch them at your peril. There are several different species. It is always fun to find one.

Friday, August 16, 2013

A duel in the (front yard) jungle

This is what my thermometer said when we got up on the morning of August 15th here in Jonesboro, Arkansas. Early in the year I predicted that after a wet spring we would fall into an endless drought and searing heat. It seemed at the time like an easy prediction to make. Perhaps the only prediction we can make anymore is that we can't make any predictions.

As for the duel of my title: We also woke up one morning to find this on a pillar of our front porch.

Sometime the day before something had happened that left this rather grisly evidence behind.   A dead two-and-a-half inch long subadult Chinese Mantis was hanging there, its legs tangled up in the deserted web of a funnelweb spider. The mantis was holding some smaller creature in its spiny grip. Instead of its usual grass-green color, the mantis was a sort of oily black. The creature it was holding seemed to be a jumping spider.

I disentangled the mantis from the web and as I took it down horrible black fluid gushed out of its mouth. Obviously sinister things must have been going on. I set the mantis and its prey down on a table so I could investigate. The prey was Phidippus audax, a very aggressive large jumping spider, a big-game hunter for its size, though of course far smaller than the mantis, which was itself a very fierce hunter. What in the world had happened?

It was like a crime scene in all those British detective thrillers Cheryl and I are addicted to: I had to use all my forensic skills to try to work it out.

First of all, I need to eliminate a suspect. The mantis was tangled in the web of a funnelweb spider. But the web was deserted. Besides, it was a small web, which would have had a rather small spider in it, which would have run in the other direction if something as big as that mantis had blundered into it.  So that spider could have had nothing to do with this.  So let us suppose the mantis walked up or down the pillar. The smooth vinyl surface would have very few places for the mantis to cling to with the claws on its two pairs of walking legs (the forelegs are reserved for grasping prey), and it would have been crawling awkwardly, perhaps with a bit of slipping and sliding. Since there are numbers of these little funnel webs on the house siding it would not be surprising if the mantis got its legs tangled in one, and found itself hanging head downward. It would have broken out of it eventually, but while it was struggling it may have attracted the eyes of one of the many Phidippus audax jumping spiders that patrol up and down the porch. Here is what one looks like before it is impaled overnight on the forelegs of a mantis, and has sticky liquid spilled all over it.

If it saw something even as big as the mantis struggling and looking like it was in trouble, it would come over and investigate. Jumping spiders are very cat-like. They stalk their prey, and when they get a few inches from it, they make a cat-like leap, catch their prey towards the front of the body, and deliver a venomous bite.  I suspect the spider would have spent some time estimating the size of the mantis, and carefully triangulating the distance of the leap. What it would not have figured on was the mantis's ability, even after it was fatally bitten, to twist the forepart of its body around and in a flash grab the spider with its muscular forelegs and squeeze it in its powerful grip with all the nail-like spines pointing inward. There would be the spider impaled on the spines, there would be the mantis quickly dead from the fast-acting venom, but also, from the digestive enzymes injected in with the venom, with its insides turning to liquid, so that, in the normal course, the spider could suck out the substance. The liquid turning black would show through the mantises translucent skin, so that the normally green mantis would look black, and the black fluid would gush out the mouth when I picked the mantis up the next day.

All conjecture, of course. Perhaps the mantis wasn't struggling in a web at all. Perhaps the daring spider merely saw it and attacked and bit it, and the mantis turned and grasped it defensively, and they both fell off some higher point on the pillar and landed in the web down below. Phidippus audax (the 'audacious' jumping spider, its name means) is so aggressive that that would be just like it, biting off more than it could chew (one charged me once, when I annoyed it).

Okay, it's why I like jumping spiders so much. I've always liked them, and kept them for pets since I was a little kid. And I kept black widows and tarantulas and scorpions and snakes. Biting and stinging things, mass murderers, yes! The rest were boring grazing animals. I had a very tolerant mother, one neutral sister, and one phobic sister who was never allowed to find out.

Thursday, August 8, 2013

More nice butterflies

In an earlier post I wrote about chasing after some attractive butterflies in early summer: The Olympia Marble, the Frosted Elfin, the Silvery Blue, and the Great Purple Hairstreak. Three of these have in common being in the group of butterflies known as the Gossamer-wings (family Lycaenidae). The other butterfly groups are more familiar to most people, the big swallowtails, and the whites and sulphurs flying over open fields, and the "regular" butterflies, the painted ladies, the buckeyes, the monarchs, the red-spotted purples.

Least familiar (and therefore most special) are the Lycaenids, which, I have written in another context, are to butterfliers what warblers are to birdwatchers. They are small, fast moving, often brightly or intricately patterned, sometimes appearing in great numbers, often very rare, always appearing unpredictably, always a pleasure to see, even the commonest ones. These are the harvesters, the coppers, the hairstreaks, the elfins, the blues.

Of the four species I wrote about in the earlier post, the marble is a white, but the other three were Lycaenids. Of the four special butterflies we have run into just now in mid summer, once again three are Lycaenids.

The first is not a great rarity, but it is so beautiful we are always grateful to see it. Some years there are a lot around, but some years they can be very scarce. This is the Juniper Hairstreak. A week or so ago we were walking along a dirt road at the Harold Alexander WMA, a road where we had often found special insects in the past. We were looking for tiger beetles, robber flies, grasshoppers, and of course butterflies. Recent rains had moistened the dirt of the road, which always brings dissolved salts to the surface, and freshly emerged male butterflies in their brightest colors were coming down to drink the salts, which they require to get into breeding condition. Cheryl spotted the tiny beautiful green butterfly (not much more than an inch wingspread) mud-puddling so intently it paid no attention to us at all. We could photograph it all we wanted, but, because it was at an awkward angle for us flat on the ground of the road, Cheryl enticed it up on her hand, to drink the salts on her skin.

A day later, taking advantage of the relatively cool settled weather, we were at Big Lake. A couple of weeks before we had been there and seen a few Bronze Coppers that looked like they could have been freshly emerged (the technical term is eclosed) from the chrysalis that day. Bronze Coppers are not only beautiful, they are also, in Arkansas, rare. Some years ago we found them at Wapanocca NWR, and then here at the Moist Soils Unit at Big Lake. So far as anyone knows, these are the only two sites where this species can be found in the state. It seems to be diminishing at Wapanocca, but it is getting commoner at Big Lake. When we found them here this year, we sent out the word, and a number of people had been here to photograph them. Now we were back checking on them, and they were everywhere, and we could not resist taking more pictures ourselves. The best thing was, the females were egg-laying on the water dock, their caterpillar host plant, which is common along the edge of the dirt path around the unit.

This was followed by a bit of serendipity, which it always is when you find a Harvester. You don't look for a Harvester, they just magically appear. This little Lycaenid has a subtle and quite handsome pattern and is noteworthy because it has carnivorous caterpillars. The female Harvester looks for some plant with an infestation of aphids and lays her egg on that plant, and the caterpillar goes off looking for the aphids to devour. But on this day it wasn't a female we found, it was a male who had set up a territory and was waiting for a female to come by (maybe they have as hard a time finding them as we do). The male carves out a territory of about ten feet along a path. He flies up and down the path slowly, showing off his tasteful pattern, and then he lands on a bush at about eye height looking around eagerly. Here he is on his bush.

Well, we don't have a Lycaenid for our fourth species; it barely counts as a butterfly. It is a Silver-spotted Skipper. And indeed we didn't even find the adult skipper, we found its caterpillar. The Silver-spotted Skipper itself is a nice enough creature which flashes a big silver spot on its underwing when it flies, but way too common to rate as being special. But you don't see the caterpillar every day, and get a chance to interact with it.

Cheryl found a rolled up pea leaf and unrolled it, and there was the caterpillar inside, immediately identifiable by its dark head capsule with the huge yellow fake eyes on it, to make it look like something dangerous to any bird that peaked inside the leaf roll. We had exposed it, so it went into its next defensive act, which was to open its jaws as wide as possible and try its best to look like the furious fiend from hell. We were impressed and rolled him back up.