Monday, August 18, 2014

Time for another Home and Away

This is the home part.

On the last one, if you remember, I told you Sleepy Orange butterflies had visited our Senna bushes and laid a few eggs, and I showed you some pictures of their very ordinary green wormy-looking caterpillars. I remember saying they would get better looking as they got bigger. Cheryl saw that and said "No they don't." She was right, they went on being ordinary, but then they made neat chrysalises.

All the sulphur butterflies use this shape chrysalis, which I guess is meant to suggest a hanging leaf. (The one on the right has already emptied out its full-grown butterfly.) When we looked a few days later, the remaining chrysalis was beginning to go transparent, revealing some of the orange of the waiting butterfly.

I took these pictures this morning. When the chrysalis is in this state, it means it will open tomorrow. We looked around the senna plant some more, and found a chrysalis like this.

The outer skin is transparent, meaning it is completely separated from the butterfly within. What you are seeing is the upper side of the forewing, still mostly rolled up. When it looks like this, it means the butterfly will be coming out this day. When this butterfly is out, its upper wing will be bright orange with a black border around it. Inside the black border you can see a little black mark like a dash. Most species of sulphurs, in this part of their wing, have a small round black spot, usually called in descriptive parlance an "eye." In the case of this species, the "eye" appears to be "closed." Hence the name of the species, the Sleepy Orange.

Sure enough, a couple of hours after taking that picture, I checked again, and the butterfly was out.

The various species of Sulphurs virtually always land with their wings closed, showing only the underside. So that glimpse of the Sleepy Orange's upperside through the pupal skin was your last chance to see the closed eye.

What else is going on around the house? A big pizza-shaped wasp nest is flourishing under the eaves in front of the house. It's one of the paper wasps, Polistes exclamans. These are quite pretty and very peaceful (if we leave them alone) so we tolerate them. The big all red paper wasps, P. carolina, tend to attack us, so I'm afraid we get rid of them. If you look in the cells you can see larvae of all different ages. A few have spun white cocoons and are pupating.

A large moth I had noticed roosting during the hot days in the rafters of our garage has finally revealed itself as a Widow Underwing.

Our milkweed plants only raised about four Monarchs this spring, in this very down year for the species. Though we did not see a Monarch in the yard lately, to our surprise we found a caterpillar munching away on the leathery late summer leaves. Monarchs are so precious now, we brought the caterpillar into the house to raise it in a predator-free environment. It has now made its chrysalis and should emerge in about ten days.

Last year was such a poor year for the big Argiope garden spiders, that by late summer we only had one left. This year by contrast we have them by the score, and some of the biggest ones I've ever seen.  But I've been looking for Argyrodes, the tiny silver kleptoparasitic spiders that live in the webs with them, and haven't seen a one. I guess a bad year for the host spider leads to a bad year for the parasite, and the parasite has still not recovered this year. But that does not mean the big spiders are free from annoying pests. The equally tiny Milichiid Flies, that follow wasps or robber flies around, often riding on their backs, or hang around spider webs, waiting for a kill to be made so they can swarm in and drink the blood and other fluids from the prey animals, are having a wonderful year. There are about a dozen in this picture. You can see the spider from time to time trying to shake them off. In the second picture, the spider had wrapped up a Polistes exclamans (very likely from the nest pictured above) and set it aside for a snack later, but the flies couldn't wait.

One day my pet scorpion was standing up looking out of the glass of its aquarium, and in so doing revealed an interesting part of its anatomy.

The funny processes coming down from between its hind legs are called pectines, or combs. Scorpions are nearly blind, and the pectines, sensitive to vibrations, are its main sense organs.

And then, there was a mystery, in fact, a crime scene, which I am trying to use my forensic skill on, developed by watching hours of detective thrillers on Netflix. As I was waking down the driveway I saw at my feet a fresh healthy looking dragonfly (Pantala hymenaea), without a mark on it, but stone dead. As proof that it was alive and functioning at the moment of its suspicious death, it was carrying in its jaws an insect it had just caught. Here is what I saw:

I carefully examined the insect it had captured, and discovered it was an assassin bug (a surface killer vs. an aerial killer). The bug has a long thick jointed beak backed up by strong venom and digestive enzymes. The beak was not now stuck into the dragonfly, but could the bug, while being fatally chomped by the dragon, have got in a defensive stab?

I was about to write this blog, when I got another piece of luck (if finding a dead dragonfly can be considered "luck"): I happened upon one of my favorite caterpillars, The Laugher, named for the uproarious expression on his face.

We brought him in, he wrapped himself in an oak leaf, and inside the oak leaf he spun a coccoon, and we will not see him again until next spring when he appears as a handsome moth. But in our brief view of him I got what I wanted, a chance to end this blog with a happy face.

Wednesday, August 6, 2014

Home and away, Part Two

For the "away" part of this two-part post, the other day we visited one of our hot spots that we try to hit two or three times a year, Shirey Bay-Rainey Brake WMA near Lynn in Lawrence County. Where we first enter, on a hill overlooking the area, we take a path through a damp woods which is  really good for robber flies (there is almost never a time we can't find at least seven species of robber fly,  including some species we don't find anywhere else), and also good for rare butterflies, for a number of other insects we don't see anywhere else, and for big spiders. Whenever we come, there are always surprises, and we almost always end up seeing something we have never seen before.

My first surprise came when I was on my hands and knees trying to photograph something and this huge, loudly buzzing, complicatedly structured thing rose up before me and went flying across the path and crash-landed into some tall grass. It took me a moment to realize it was so big because it was two things, both large. It was a pair of Swamp Darners, one of our largest dragonflies, in mating tandem, flying along hooked together, one doing all the work, the other hanging on and supplying so much dead weight they could scarcely get off the ground, and when they landed on some wispy stem of vegetation they weighted it down to the ground.

The female here, about four inches long, and with impossibly blue eyes, is upright, the male is lying on his back.

The next thing we saw trundling along the path was a Bess Beetle, harmless but imposing as it was as big as the last joint on my thumb. These feed on wood and are often to be found under the bark of fallen trees. They are famous for their good parenting, carefully feeding their larvae which live together with them and are completely dependent on them for food. They have a sort of language they use to communicate with each other, made up of different squeaks they make flexing their joints. Wood is mainly cellulose, and the beetles need lots of gut microorganisms to help digest it, and the adults hand the microorganisms on to the young by feeding them pulp pre-chewed and pre-mixed in their own guts. Very specialized mites live on the bodies of these beetles, seldom leaving them. These mites don't feed on the beetles. I guess they feed on decaying wood too and just use the beetles for transportation from one good log to the next. The relationship is called phoresis, from a Greek word for carrying, and is rather common among a number of insects.

The path (just by the skin of its teeth) lived up to its robber fly reputation. We quickly saw five very common species, and then for the sixth, we saw one of the specials for this habitat (shady and rather damp), a Machimus snowii, a rather slight and neatly dressed species that feeds on the moths that it finds in the shadows.

And for the seventh and last species of the day, we saw what looked like a very small bee (6-7 mm) but which we knew instantly from our years of searching for robbers was a robber with a banded bee-like abdomen (a robber fly in bee's clothing). This one was named Psilocurus birdii.

When we take this particular path there is one creature we are especially looking for. This is one of two known sites in Arkansas for a big woodland butterfly, the Appalachian Brown. It was not a good day for them. I myself didn't see any, but Cheryl, walking along parallel to the path but about thirty feet off in the rough, caught a glimpse of one flying away.

But all of these were not the most fun of the day. This path is often too wet and muddy to walk on, but on this day it had been dry for a long time and even the deep puddles in the middle of the path were dry, and they were full of abandoned crayfish holes and broken off chimneys. Cheryl was the first to notice that rather large creatures were diving down these tunnels as we approached, and when we looked into one of them, we could see a large spider disappearing underground.

We came to the end of the path and turned around to start back to our car, and this time we came up on the crayfish holes very quietly. We found the spiders outside the holes, very shy and ready to disappear in a flash, but we still managed to sneak up close enough for some photos. We were on our hands and knees, and finally on our stomachs.

These were all large wolf spiders in the genus Hogna, H. georgicola I am pretty sure.

Well, we were almost back to the car, thinking, or at least I was, rather smugly that there is not very much we miss with our special way of walking slowly, searching high and low, under and over, when Cheryl suddenly shouted at me to stop. I had nearly stepped on a small flower growing in the center of the path, I must nearly have stepped on it on the way down. It was bright pink, about a foot tall, standing in the open in plain sight. And I would have missed it again, walking straight past it again. It was one of the rarest orchids in the state, in full bloom. It was the Purple Fringeless Orchid.

Let's look at it from closer up.

It looks pretty much like it has a fringe at the lip, but it is called "fringeless" to distinguish it from the Purple Fringed Orchid, which evidently really has fringes.

This is our favorite way to spend the day (even though it means spending the evening picking off tiny nearly invisible ticks, and scratching our new sets of chigger bites).

Monday, July 21, 2014

Home and away, Part One

Our yard has reached that degree of perfection that essentially come spring we don't plant anything, we don't weed anything, we just step back and let it all come up of its own accord, and each year it comes up taller and thicker. Our favorite habitat in the world is the tropical rain forest, and this is as close as we can come in our temperate clime. Oh, it might be a bit overgrown, in places there are thickets we no longer have access to, there is so much aquatic vegetation in our pond we can no longer see the water surface. But the only regret I might sometimes have is that when we were first here I kept planting more and more trees, tiny saplings that have now grown into big trees, and it is getting as shady as the woods across the road from us (which is itself getting overgrown), and that might reduce some biodiversity, but there is still plenty here to keep us occupied.

For example last year I found an amazing 104 species of spiders here in our yard (and house), and, when I used to keep track, we regularly found over 60 species of butterfly in the yard every year (though I doubt we still could find that many as the yard becomes more enclosed in the woods, and also as butterflies continue, as I suspect they are, their steep decline generally).

There is still lots of butterfly activity. The brash and bright colored Zabulon Skippers have taken over the pond and chase off everyone (including me) who comes by.

All in the hopes of winning the  heart of the quiet and gentle female of the species.

The handsome Black Swallowtails are laying their eggs on our bronze fennel, and these are hatching out and growing into big, striking caterpillars.

Horace's Duskywing (some classicist named a bunch of duskywings: Juvenal's and Propertius are others) are courting and mating.

A pretty little Sleepy Orange appeared in our garden, nectared on our flowers, then laid its eggs on our senna plants. The nearly microscopic eggs have now hatched and the rather ordinary looking caterpillars (the later instars are more attractive) are growing rapidly.

A Buckeye butterfly has just today eclosed from its chrysalis.

When it was ready, it flew off and we thought it was gone, but then Cheryl found it in a far corner of the yard and took this beautiful picture of what might be our most beautiful butterfly.

Of course there are a lot of interesting moths and moth caterpillars as well. We especially like this one, a Double-toothed Prominent. The back of the caterpillar mimics the double-toothed leaves of the elm trees on which it feeds. As it eats one leaf from the edge in towards the midrib, it fools birds into thinking it is merely the other half of the leaf.

There is a whole ecosystem beyond the lepidoptera, including a number of predators. For instance this very big Laphria grossa, a bumblebee-mimicking robber fly, here with its decorative prey (robber flies have a nice design sense), a flower scarab.

On a smaller scale, this tiny assassin bug has caught a Cuckoo Wasp. The wasp has such strong armor plating an entomologist would have a hard time sticking an insect pin into it, and yet this fragile bug has managed to stab it with its beak.

That was an assassin bug with prey. Here is an assassin bug as prey. The spider is the handsome Paraphidippus aurantius, the Emerald Jumper.

The Cuckoo Wasp was prey, but here are some wasps in their more usual role as predator. I read in my Eric Eaton Kaufman Field Guide to Insects that there are 280 species of wasps in the subfamily Eumeninae, the Mason Wasps and Potter Wasps. These are all very similar appearing black and white or black and yellow wasps that make use of abandoned nests of mud daubers or carpenter bees or other cavities for their own nests. They fill these cavities with paralyzed caterpillars and then lay an egg in them. One of these wasps right now is using a space where canvas is folded over the top of one of the chairs on our front porch. It seems like every time we come out it is dragging another hapless caterpillar up the chair leg.

Some members of this group, those in the genus Eumenes, are called potter wasps, because they make their own nests, exquisitely shaped clay pots using the coil method of construction that they invented millions of years before we did.

When I started this post I just called it "Home and Away," planning to contrast this account of what we are seeing around our home right now with what we see going out for the day to one of our favorite places. But now I see that I could go rambling on about what we are seeing around the house almost endlessly. So I'm going to stop here, and in the next post (Part Two) I'll do "Away."

Well, I'll mention one more thing. What I have done for the last couple of nights is to go out at late twilight and try to take pictures of the fireflies just at the instant they are flashing. What I do is run over to where I see flashing, look in its direction through the view finder focusing frantically back and forth till I catch the tiny flying black dot in the near darkness, follow it trying to keep focused on it, then try to catch it in mid flash. What I usually end up with after several tries is one picture where the firefly is in quite good focus, but not flashing, and one that is flashing, but out of focus. If I knew something about photo-shopping, maybe I could meld them together. Anyway, try it. It's fun.

Sunday, July 6, 2014

The Black-and-yellow Garden Spider, Argiope aurantia

If you have an overgrown garden you have benignly neglected for many years, if you never use pesticides, if you have fervently absorbed Oliver Rackham's (in his great book, The Illustrated History of the [English] Countryside) sternest and most important dictum about having a garden, "Learn to detest neatness," then by mid summer you are bound to have at least a few Argiopes behind bushes or in ignored corners, those enormous golden garden spiders sitting in the center of their big webs with the zig-zag stabilimentum going down through the middle. I have been observing them for years, always learning new things.

Now, these big brightly colored spiders seem to appear out of nowhere. They aren't there one day, and the next day suddenly there they are. Well, if you start really looking you find they are there all the time, only in smaller, less recognizable instars. It might take you a couple of seasons, but eventually you push them back to the beginning. Maybe the first day of summer, June 20th, is a good day to start looking out for them.

What you'll see first, down low in thick vegetation, is a white thing about the size of a postage stamp.

Take a close-up with your digital camera and you will see a tiny spider. The only similarity it has with a full-grown Argiope is that it is sitting head down with two pairs of legs forward and two back. The stabilimentum, instead of going up and down in a zig zag, is a tightly woven squarish circle just the size to hold the spider's body and legs.

Nobody knows precisely the purpose of a stabilimentum, though recently it has been shown that they reflect ultra-violet light, and thus might act as an attractant to insects. But this baby stabilimentum has its own neat little function. Now you see the spider, but at the least disturbance, the spider vanishes quicker than you can see.

After another instar the silk mat is a bit larger, to hold a spider that is beginning to look more like an Argiope.

By another instar the spider is still too small to be noticed unless you are deliberately looking for it, but now the baby mat is beginning to extend into the up-and-down zig zag of the adult.

It can still perform its disappearing act.

With the next instar it has its adult stabilimentum.

And then, its adult color and pattern, though its abdomen still has its long narrow shape, not yet its rounded adult shape.

Interestingly, I saw all these different stages on the same day last week. The progress is very irregular. I think the tiniest spider must set up shop, and just wait for insects to come. If they don't, it stays the same size, if it makes a couple of lucky catches, it molts up to the next stage, and the more insects it catches, the quicker it moves from stage to stage, while the unlucky spider with a poor spot sits waiting. Even quite late in the summer I have seen that first postage stamp size, while the huge fat adult females are laying egg nest after egg nest.

At any rate, with decent luck, at last the spider reaches the penultimate molt, and males, battling one another, begin hanging around the edges of the web, to be the first one there when she sheds into full adulthood ready to mate. Here is that next to last molt, and she still has her girlish waistline, before it starts ballooning out with eggs.

If you want to follow the story, I've done an album of the life history of Argiope aurantia which includes a life history of Argyrodes, the tiny spiders that live parasitically in Argiope's web.

Click here