Monday, October 1, 2012

Some Spiders

Fall is upon us, and you might have noticed an increase in spiders, especially large orbweavers. You might be wondering why the sudden increase in spiders, but there actually hasn't been an increase.  The spiders people are noticing now have been spending the entire summer eating bug after bug and using that energy to grow larger and larger. Of course, the larger the spider (or any animal for that matter), the better the chance people have of noticing it. The majority of these conspicuous spiders are females. They've been trying to gain mass (and therefore energy) to produce the eggs for the next generation. Spiders are a varied bunch and have a variety of life cycles. While some spiders, especially web-spinning spiders, can live for a handful of years, most individuals don't even make it through the summer due to predation, parasites, and other factors. Many will hatch in the Spring, live through the Summer, lay eggs, and then die in the Autumn (as everyone familiar with Charlotte's Web knows).

Natural histories aside, here's a few very cool spiders I recently found at A.W. Marion State Park, in Pickaway County, Ohio.

Spider number one. This is a Hentz's Orbweaver, or Neoscona crucifera. I found it hiding out on the half mile trail located near the dog beach. It was a pretty large spider, and that is even with it sitting all bunched up like this. Orbweavers, like this one, are well known for the circular webs they spin, the "classic" spider web if you will.

Orbweavers, family Araneidae, come in a wide variety of colors and patterns. For example, the previous one we saw was reddish-orange, while this one is much darker with contrasting white patches. This species is the Arabesque Orbweaver, Neoscona arabesca. This one was also hiding out among the vegetation waiting for night to come. Once the sun starts to set, this female will come out and rebuild that classic orb web to try and catch some goodies, like maybe a Bristly Cutworm moth. Web-spinning spiders, such as orbweavers, actually rebuild their web every day, which might come to a surprise to most people. Although the material is relatively strong, daily wear on a web creates holes while "trash" might also collect at the same time, making the web more visible to potential prey. To ensure a productive night, these spiders will tear down their old web and build a new one for that day.

Since we're on the subject of orbweavers, let me introduce you to the Furrow Orbweaver, Larinioides cornutus. If you live in the country, you're probably well familiar with these spiders, but maybe not by name. I know that where I live, there are hundreds of them that call the sides of my house home. They range in sizes, with some getting quite large, but are quite harmless. They might bite when provoked, as most spiders do, but that's the only bad part. No nasty venom or anything. There are three species of furrow spiders, genus Larinioides, but you can identify this species by the lack of a dark middle band on the metatarsus. The metatarsus is the second to last part of the leg; you can see a diagram of a spider leg to see where I'm talking about at the following link: Spider Leg Diagram. Notice how this individual has a dark band at the end of each leg section, but it doesn't have a second dark band on the metatarsus. This designates it as the species Lariniodes cornutus.

Here's the other side of a Furrow Orbweaver. Notice the bristly leg hairs that many orbweavers have. Orbweavers' diets typically consist of moths, and some of the Furrow Spiders at my house have it made. There are four or five individuals that make their webs around my backyard light. This light attracts moths, the moths go to the light, hit the webs, and bam, buffet for the spiders. 

Another very common spider is the Grass Spider. They are apart of the Agelenidae (Funnel Weavers) family. These are unrelated to the deadly Funnel Web Spider of Australia, mind you. You probably know these guys from their webs, which have a tunnel in which they normally sit. They sit at the end of this tunnel and wait for a bug to land. When one does, they dart out and give the bug a quick bite to kill it. This individual was very photogenic, and barely batted and eye when I was inches away snapping photos. Typically Grass Spiders are very skittish, and any change in lighting or vibration in their web which isn't reminiscent of an insect will make them quickly retreat into their protective tunnel. If you want to see one of these spiders in action, grab a small stick. Very gently, tap a section of their web as if it's an insect that just became stuck. If you're convincing, the spider will run out and bite the stick. Of course, the spider will quickly realize it isn't an insect and will run away, but it's really awesome to watch them hunt. Each spider seems to have its own personality (some are more shy than others, while others will investigate any kind of movement in their web), so you might have to try this with a few individuals to get it to work.

Slight tangent, but I need a good macro lens. My kit lens doesn't cut it for these smaller spiders. Anyway, back to spiders. This is the common Trashline Spider, or the Trashline Orbweaver, scientific name Cyclosa turbinata. There are actually two kinds of Trashlines, and the species turbinata can be told apart from conica by the female's anterior dorsal humps, which you can see here.




Trashline Spiders are interesting because of their camouflage. They collect debris of eaten insects and line it up and down in their web. They look like this "trash" themselves, and bugs don't even know there is a spider there. The females sit in the middle of their web, and the middle of the trash line, patiently waiting for an insect to get stuck in their web. 

Spiders are really awesome once you get past the initial "ew" and fear factor we have. Next time you see one, especially an orbweaver, take a closer look. Really look at their details. You will be amazed.

2 comments:

  1. I just saw a spider today, I've never seen before, nor can I find anything that looks like it online. It was quite large (it's body alone was larger then a quarter), It had a VERY large abdomen, the color of a cardboard box and appeared slightly fuzzy. The legs were a bright red and black stripped. We are in South West Ohio. Do you know of a website to help identify something like this?

    ReplyDelete
    Replies
    1. Hm... First, did it look similar to this? http://3.bp.blogspot.com/-qcbup-ezWdI/Ui5wMBckaiI/AAAAAAAAQRk/OrZcEVInpI0/s1600/3+Variable+Orbweaver,+Neoscona+crucifera,+Franklin+Co.,+OH+August+31,+2013+%2812%29.JPG

      As for a website, many ID websites are based around posting a photo of the spider. If you could get a photo of it, you could post it to www.bugguide.net for an ID. You could also browse ODNR's guide to common Ohio spiders to see if you can find a match. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDUQFjAB&url=http%3A%2F%2Fwww.dnr.state.oh.us%2FPortals%2F9%2Fpdf%2Fpub5140.pdf&ei=S1hLUtfiMde54APu-YDACQ&usg=AFQjCNHb5mlt00VlKw7gRKeTOZvbyg6O6A&sig2=JXQIZAkPjmAFjQogO-DZJg

      Delete