Sunday, October 14, 2012

Hanging desperately onto summer.

We dragged all through a dreary insectless winter waiting for summer to arrive, got a few promising weeks of spring, then it came in hot and dry, and we (and all the insects) hunkered down through most of the summer months waiting for it to let up a little. And now, overnight, it's turned cool, dark, and drizzly.

We feel like we've been cheated out of a season.

The event of the year I guess has been the irruption of neo-tropical butterflies into Arkansas, or at least the SW part of it, Charles Mills sitting pretty at Lake Millwood ticking off Dorantes Longtail, Ceraunus Blue, and Queen so far. Someone else had a Mexican Yellow.

We hadn't been to the southern part of the state all year, and thought we would go down to SE Arkansas looking for grasshoppers, and at the same time keep our eye out for our own exotic butterflies coming up from the Gulf. We went down Sunday (the 8th) and rented a motel in McGehee, in Desha County, for three nights. Monday morning we met up with our friends Carl Ramm and Susan Alexander (she is assistant refuge manager at Felsenthal) and they showed us some special parts of Felsenthal we had not seen before, mainly a sand prairie (ideal for grasshoppers and interesting wasps). From now on when we come down, it is the first place we'll visit. We had a terrific walk through it this time, but it was mainly overcast, and the temperature never quite reached 60 degrees, so I'm sure we didn't see nearly what we might have on a sunny warm day. Even so it was teeming with grasshoppers, especially Seaside Grasshoppers, which were in huge numbers, as they seem to be wherever there is white sand for their pale bodies to disappear into. They were constantly flushing before us, we would get a brief flash of bright lemon yellow wings, then they would vanish again. There were also nice butterflies, but not the Ceraunus Blues I had my eye out for.

In the afternoon our friends had things to do, and left us to continue noodling around the sand prairie. We then drove up and down the dirt road along the eastern edge of Lake Jack Lee, making stops where the road bridged over creeks. In past trips we had found the stone work under these bridges swarming with big cottonmouths, but we didn't see a one on this cool and cloudy day.

But we did find something nice. Because we were looking so closely for insects we suddenly realized there were grasshoppers sitting within the grooves of the trunks of big pine trees. Mostly they were at a level of three or four feet above the ground on the massive boles. We knew at once these were Pinetree Spurthroated Grasshoppers. The field guides always say something like "little is known about this mysterious grasshopper, that may be nocturnal, and spends almost its entire life up in trees." Though they are hard to see, we believe they are very common, at least in Arkansas, and we are learning more and more about them. Mainly we see females, and that is because they have to come down out of the trees in order to lay their eggs in the ground. And we know they are not found only on pine trees, since we have found them on eastern redcedar trees, and also oak trees. But these we were seeing this day were following the rules and living on pine trees. And every one we saw was a male, as we could tell by the large boot-shaped claspers at their tail end, a part of their complicated genitalia. Here is what we think was going on: Every female scattered all over this enormous tree has to come down past this relatively narrow trunk to reach a place on the ground to oviposit. We think the males were waiting there to waylay them, and make sure some of their own genetic material goes into the eggs. We have seen this in several kinds of insects: the males waiting at just the perfect egg-laying place the females are searching for.

Tuesday we went to Warren Prairie. A couple of years ago when we were there in the spring we had photographed nymphal Eastern Lubber Grasshoppers. This time we were hoping we would find some of the big brightly colored adults to photograph, but we didn't have any luck. Maybe this time we were too late. It was a bit warmer this day, and there were lots of butterflies out, but once again, all of the expected ones, and none of the exotic ones. But it was fun walking through the area, though we had to stick to the high ground. The low areas were ankle-deep in water, the drought evidently not as bad in the southern part of the state as it was up by us. There were dense patches of glaucous-colored goatweed along the road which we carefully checked for insects, and several times found the egg nests of Green Lynx Spiders, which seemed to be exactly the shape and color of the flowers. Each nest had a spiky-legged pale green mother spider wrapped protectively around it. (Here's a picture of one on goldenrod, which is a little easier to see them on.)

We still had much of the afternoon left, and on the way back towards the motel, stopped at Seven Devils Swamp. If Warren Prairie had been under water, it was the reverse here, and the swamp was bone dry. We threaded our way in among the roots and knees of the densely packed bald cypress and tupelo trees, and had the odd sensation that we were walking at the bottom of the sea. The landscape of twisted trunks ahead of us was both beautiful and sinister.

Wednesday morning we went east from McGehee to Arkansas City. During the great Mississippi flood the people of the town stood on the top of the high levee looking out on the river to see how far it would rise. They didn't realize a levee on the Arkansas River had breached behind them, until they turned around and found the flood water was rising up inside the levee faster than it was on the Mississippi side. That levee they stood on was the one we crossed now to go out to Choctaw Island. We drove out to the boat launch at the end of the road. This is always a good place for insects, and though it was still dull and overcast, the day was warmer, and there was more activity. Cheryl found a spectacular Festive Tiger Beetle in a full spectrum of glowing colors. I saw a jumping spider looking over the head of a butterfly it had caught. We decided it was a spider-headed were-butterfly.

We moseyed our way down the dirt road beyond the boat launch till it ended in a big sandy field full of Ridgeback Sand Grasshoppers nearly invisible against the substrate.

And then we saw something even more invisible, more like a bit of shadow than a living thing. It was one of the tiniest robber flies, only a few millimeters long, its name much longer than it was, Stichopogon colei. In Arkansas they are only found on sandy beaches of the Arkansas River. Choctaw Island is only a dozen miles south of where the Arkansas empties into the Mississippi and so the species extends its range down at least that far. We had not seen one for years. Cheryl got a terrific picture of it, looking more like a delicate midge than the powerful micro-predator that it is.

The real fun was when we turned around and came back along the road towards the boat launch. Perhaps during breaks in the overcast the weak sun had managed to warm the exposed roadway. Snakes sluggish with cold were crawling out onto it. First we saw a medium-sized cottonmouth still with a good bit of pattern (the bigger they get, the darker and more obscure the marking). We got closer and closer taking pictures of it. Until we crossed a certain line and it gaped its white fang-filled cotton mouth at us, showing where it got its name. We didn't get closer.

Down the way was another, this one darker and more obscurely marked. It also objected to our too near approach. But then the star performer of the day appeared, what looked to us like a near record-sized diamond-backed water snake. Don't think only venomous snakes have heart-shaped heads:

As a coda to the day, just before we headed back to Jonesboro, a juvenile cottonmouth came out. Notice the yellow tail tip. It's a feature of many species of pit viper, this yellow tail-tip, when they are young. It seems too incredible to believe, but herpetologists have witnessed it: The snake stealthily approaches a small lizard, and then waggles the yellow tip. The lizard rushes up to capture the waggling worm-like thing, and the snake nails it. It's where their first meals come from.

1 comment:

  1. "glaucous-colored" WTF? Your vocabulary amazes me!

    As to the diamond-headed water snake, I was once kayaking on Lake Norfork and saw a huge water snake engaged in a life-and-death battle with a really gigantic fish. The war raged on for about twenty minutes. The snake won. And then I watched the snake slowly swallow the big fish whole. It limped off contentedly with a massive lump in its guts.