Awesome Arachnids

She asks me to kill the spider.
Instead, I get the most
peaceful weapons I can find.

I take a cup and a napkin.
I catch the spider, put it outside
and allow it to walk away.

If I am ever caught in the wrong place
at the wrong time, just being alive
and not bothering anyone,

I hope I am greeted
with the same kind
of mercy.

~Rudy Francisco

I led a full moon walk this past week at Mason Farm Biological Reserve, a wild and wonderful tract managed by the NC Botanical Garden, only a mile or so from my office. I love being outside at night, hearing the night sounds, and trying to catch a glimpse of the creatures that make darkness their time of choice. The night before the hike, I walked alone along the trail at Mason Farm, looking for things to highlight and reacquainting myself with the brilliance of an almost full moon. A variety of night sounds greeted me as I walked in silence – the startling snorts of alarmed deer, a solitary hooting of a Barred Owl, a lone tree cricket…but the most magical was when a group of Coyotes initiated their yipping and howling as the moon rose above the tree line. Though it lasted less than a minute, it is a sound that sticks with you (and might even raise the hairs on the back of your neck a bit). Chilly night temperatures, combined with recent floods, seemed to reduce the number of night-time invertebrates that were out and about.

Ther Laugher Moth larva on oak

A fuzzy larva of The Laugher Moth feeding on oak, my only glow-in-the-dark caterpillar this past week (click photos to enlarge)

I searched with my ultraviolet flashlight for caterpillars, hoping to find some of my favorite slug larvae species, but came up with only two fuzzy larvae of The Laugher Moth. But there was one group well represented and quite noticeable, if you know how to look…

Carolina wolf spider 1

Carolina Wolf Spider, Hogna carolinensis, out and about along the edge of a field

Yes, that’s right, and somehow theme-appropriate at this time of year, spiders! On my pre-trip, they were everywhere, especially concentrated along the habitat edges (boundary between forest and field) and along the stream banks and swamp edge. If you don’t know, you can “sniff” spiders by holding a flashlight near your eyes or nose (or wear a headlamp) and scanning your surroundings. On almost any night from March through October, you are likely to see what look like dewdrops scattered across the ground. These are most likely spider eyes reflecting your light back to you (some may be dew drops if it is damp). If you are just holding a light down by your side, their reflection comes back at that level and you probably can’t see it. That’s where the sniffing part comes in. You tell your group you smell a spider. Since most people don’t usually walk around with their flashlight up near their eyes, they can’t see the eyeshine. On my program walk, I was able to run about 25 feet over to a tiny spider on a tree trunk by keeping my light on it to see its eyeshine. Of course, you always share that trick with your participants so they can see for themselves the incredible abundance of these spiders.

Hunting spiders, like wolf spiders, have a reflective layer in their eyes that bounces the light around so that there is a better chance to have it absorbed by the rod cells that help them see in low light. This is similar to what happens in the eyes of nocturnal vertebrates like deer and cats. One of the larger species out this time of year is the Carolina Wolf Spider which generally hides in underground burrows during the day, and then emerges to hunt prey at night. Females carry their egg sac off the tip of their abdomen. The baby spiders hatch and ride on the mother’s back for a week or so until they molt and then disperse.

Rabid wolf spider

A large, female Rabid Wolf Spider, Rapidosa rapida

Another large, and quite common, ground hunting spider is the oddly-named Rabid Wolf Spider. Its common and scientific names come from its rapid movements, not any ability to carry a mammalian disease. The bold stripes on the cephalothorax (the front body part that is sort of a head and thorax combined) are diagnostic of this species (along with some more subtle features). Males are distinguished by their smaller size and by the first pair of legs being black.

marbled orb weaver

A Marbled Orb Weaver, Araneus marmoreus, in her web

There are relatively few web builders left out in the fields and woods this late in the season, but there is one notable exception, the Marbled Orb Weaver. This distinctively colored (yellow or orange abdomen) spider can be found in woods and along field edges into November. During the day, the large female hides in a folded leaf retreat along the edge of her circular web. She holds a line of silk attached to the web to detect and struggling prey. At night, they are more typically found perched in the center of the web. Their color scheme and occurrence through late October has given them another common name, the Halloween Spider. Web-builders typically have no eyeshine since they rely less on vision and more on vibrations of struggling prey in their web to obtain their meals.

Dolomedes spider

A huge Dark Fishing Spider, Dolomedes tenebrosus, on a tree trunk at the edge of the swamp

The best spider find on our tour was made by one of the participants as we stood near the closed portion of the trail through the swamp. Hurricane Florence took out the boardwalk through this section so you can no longer walk the circular route. But, perhaps because of that pause, we got to see one of our most spectacular spiders, a very large Dark Fishing Spider. This large female would almost fill my palm. They are frequently found head-down on tree trunks (like this one) near water, but can occur quite some distance away. I have them in my workshop and frequently find their sheds scattered among my scrap wood or tools. There are other members of this genus that are more frequently found on and/or in water (e.g. the Six-spotted Fishing Spider) where they actively hunt for creatures that fall on the surface, or those that live just beneath (like aquatic invertebrates, tadpoles and even small fish). Female fishing spiders carry their egg sac beneath them, hanging onto the silken bag with their chelicera. When the young hatch, she creates a nursery web for them where they stay for a short while before dispersing.

bread

Even the bread, Greatbreadus multigrainiia, at the Farmer’s Market is arachnid appreciative

I had a chance to write up some of this on Saturday, but not before I made my weekly trip to the Carrboro Farmer’s Market. There, I spied one more thing to add to this post – a loaf of beautiful bread from Chicken Bridge Bakery. So, whether its a graphic on tasty bread or an eight-legged critter on the trail, take the time to learn more about these awesome arachnids. If you want to learn more and see some incredible photos, check out some of the scientists I follow on Twitter – TurnFear2Fascination, Catherine Scott, and Thomas Shahan…you, too, will learn to appreciate these amazing creatures even more. Happy Arachtober!

Those Eyes

Could a greater miracle take place than for us to look through each other’s eyes for an instant?

~Henry David Thoreau

On any woodland walk in the warm months, you will run into a variety of spider silk across your path. And so it was recently on a walk in our woods. It was mostly webs of small orb web weavers strung across the trail, but at one point I found myself staring at a spider dangling at eye level. I reached for it and realized the spider was no longer there, just its last set of clothes – a shed exoskeleton.
spider shed

Spider shed that was hanging by a thread along the trail (click photos to enlarge)

I am always fascinated by the remains of insect and spider sheds. The lighter-than-air remains cause them to dance in the slightest breeze, but the detail of their former inhabitants are so revealing and beautiful. In spiders, they have a pop-top shedding style so the cephalothorax is removed like a can lid so the “new” spider can pull itself out of the tangle of old leggings.

spider shed on moss

The eye coverings remain on the shed head seen on the left in photo

When I touched it for a closer look, the shed dropped to the ground and landed on a mossy rock. It looked as if the spider was ready to run off again, but with its head oddly trailing behind.

As we approached the house, I checked the small pawpaw patch out back and noticed something disappear under the broad leaves of a small sapling. I eased my hand under the leaf and a spider popped back out on the upper surface.

Magnolia green jumper male 2

Magnolia green jumper on pawpaw leaf

And what a spider it was! I have photographed the female of this species, a magnolia green jumper, but had never seen a male. They are characterized by the two huge eyes in front and their insanely long chelicerae.

Magnolia green jumper male under leaf

The magnolia green jumper under the leaf

This little guy was quite active and bold. I had to coax it out from under a leaf at first, but then it tended to move toward the camera and even jumped on the lens a few times. I would then ease it back onto a leaf and start the photography dance all over again.

Magnolia green jumper male eye arrangement

There are four rows of two eyes each, with the two in front being very large

Both sexes have a raised “eye mound” with 8 eyes surrounded by orange. These spiders can scan the area in front of them by moving the rear of their lens (the actual “eyeball” is fixed since it is built into the carapace). Because the rear of the lens is the darkest part of the eye and it moves around, you can often see a jumping spider’s eye changing color as in the photos below. When it is darkest, the spider is looking straight at you, because then you are looking down into its retina.

 

Magnolia green jumper male eye closeup 1

The retina sweeping side to side in the eye

This series of photos also shows the chelicerae (jaws) – the brownish orange appendages coming out beneath the eyes. Coming down on either side of those are the pedipalps (or palps).

Magnolia green jumper male eye closeup

One eye dark, one lighter

Pedipalps resemble small legs, but, in males, they serve a reproductive function.

Magnolia green jumper male eye closeup 2

Here’s looking at you…

The tips of male pedipalps are modified with small swellings (that look like small boxing gloves) that contain a complex copulatory organ. Males deposit sperm from under their abdomen into a small sperm web and the then suck it up into the palpal organ. When he finds a receptive female, he inserts the palpal organ into a slit on her abdomen and squeezes out the sperm. I suppose it is safer that way considering she might want to make a meal of him. Probably another reason to have a lot of eyes if you are a spider.

 

Hiking the Haw

A river is the most human and companionable of all inanimate things. It has a life, a character, a voice of its own, and is as full of good fellowship as a sugar maple is of sap.

~Henry Van Dyke

Haw River reflections 1

Autumn reflections along the Haw River (click photos to enlarge)

Fall color is starting to peak here in the Piedmont of North Carolina so I thought it would be a good time to hike along the nearby Haw River. The Haw is part of the Cape Fear River basin and the stretch that runs through this area is gorgeous, especially in early morning or late afternoon light. Last Friday, I got a ride down to the Hwy 64 bridge and hiked upriver a couple of miles to our neighborhood. I traveled light – the usual binoculars, a hiking pole to clear the path of spider webs, and my new Olympus Tough TG-4.

Haw River reflections

Haw River reflections

The early morning light accentuated the arboreal palette and made me wonder why I had waited so long to enjoy this beautiful hike. A few years ago, about 1000+ acres along both banks of this stretch of the Haw were acquired by the state as the Lower Haw River State Natural Area. The actual trail lies along a little over 4 miles of the east bank, from the Hwy 64 bridge to Bynum. For a couple of miles it runs along the boundary of our community, making for easy access to enjoy the sights and sounds of the river.

Haw River reflections 4

Morning sun peeking over the treetops in a reflecting pool along the Haw

The path is narrow, occasionally littered near its start by thoughtless bank fishermen, but you soon leave that and the road noise behind and are accompanied by the gurgling sounds of water over rocks.

Haw River reflections 3

The Haw has many moods, from quiet and reflective, to roaring and dangerous at high water

On this day, the river flowed gently over, and between, the many rocks that line its corridor.

Haw River reflections 2

The river level gave rise to many boulder-shrouded pools where waters were still

Evidence of recent high water is suspended in the shrubs and trees along the bank, but now I can step out into the river on the many exposed boulders that frame quiet pools. There still is enough flowing water to muffle many of the sounds of the forest along the trail, but I did hear the unmistakable chirping of a Bald Eagle at one point, before realizing it was perched in a tree right next to me. As I slowly eased toward the river bank, it flew across and perched in a large Sycamore, so I moved on, leaving it in peace. I saw a few other birds along the way, plus a lot of animal sign like Beaver chew marks and the tracks of Raccoon and White-tailed Deer. And, since it was a warm and sunny morning, there were plenty of insects and spiders out and about. A hatch of caddisflies was happening on the river, and several of these tent-winged insects landed on me as they began their aerial existence from what has been their aquatic home. I also encountered more than my share of spider webs strung across the trail (always a good sign that you are the first person to hike a trail that day). After scrambling up the bank at the main creek crossing along this section of trail (there are no bridges for the side creeks feeding into the Haw), I saw one of my favorite autumn arachnids.

Marbled Orb Weaver

Marbled Orb Weaver

Marbled Orbweavers, Araneus marmoreus, are large, brightly colored spiders, most often seen in late summer and fall. This one is a female, much larger than the males as is so often the case in the world of spiders. She was hiding in her daytime retreat, a curled leaf, off to the side of her large circular web. She pulls the leaf into a curl with silk and then hides in the safety of the retreat awaiting a signal from a struggling prey. She is able to feel their floundering via a strand of silk, a signal line, that runs from the center of the web to her hide.

Marbled Orb Weaver leaf retreat

The leaf retreat of another Marbled Orbweaver just a few feet away (look closely and you can see the spider inside)

Unfortunately, I had stumbled into her web as I climbed over a log, and pulled open her retreat. She posed for a few photos in the morning sun, and then I placed her back on the limb where some of her web remained. Just a few feet from that limb was another large web, and, sure enough, another spider hiding in a leaf retreat.

Marbled Orb Weaver 2

My spider had a glob of some sort of prey in her mouth parts that she continued to hold during the photo session

The colorful abdomens of these spiders tend to darken with age, so many appear bright orange by late October. This has given rise to another of their common names, the Halloween Spider.

Marbled Orb Weaver shadow

I caught her shadow on a branch below as she returned to her remaining web

Perhaps this species is one of the reasons spiders are often associated with this spooky holiday. Several scientists even started a spider awareness campaign on Twitter for the month of October to take advantage of this perceived connection – #Arachtober. They have some incredible photos and fascinating information about this too-often misunderstood group of invertebrates. In honor of their efforts and the important role that spiders play in our world, I will try to post a few more spider topics this week.