This odd yet pretty little spider is a Spined Micrathena (Micrathena gracilis), they are very common in gardens and woodlands throughout Eastern North America. I see them all the time in my backyard flower gardens.....I easily have a dozen or more of these little females sitting in the middle of their simple yet effective web. These webs will measure approximately 30 cm (6 to 8 inches) in diameter. Like most spiders, only the female is responsible for web building. The males are capable of producing silk, but it used in mating rituals only. Males will carefully approach the web, and using his legs will tap out specific signals to the female on a specific piece of silk that he will use to attach to her web. If the female is feeling amorous, she will not eat him. Mating will occur and if he is quick enough he will live to see another day. The life of a male spider is truly a life lived on the edge. He is almost always at the mercy of the mood of his potential mate. The female will lay eggs in a sac woven of silk that will overwinter near the original location of the web; usually hidden in the bushes. It takes approximately one year for them to complete their lifecycle.
These are relatively small spiders; females measure up 1/2 of an inch in length, males are about half that size. They are a glossy black with white spiny abdomen, males will have no spines and will be lighter in color. There will be a total of 10 spines located around the perimeter of the abdomen.The spines on the abdomen are an adaptation that protects the spider from being eaten. They are quite sharp and can even draw blood if smashed against your skin. Any bird, frog, or other insect bent on munching on this spider would get a nasty surprise when the spines hit the palate. I would assume it would feel very much like munching on a cocklebur.
They mainly feed on flies and other small insects. Their web is too small to contain very large prey. Butterflies and large moths would most likely tear the web to pieces. While walking through the timber these are the most commonly encountered webs in this area. There is very little that is more discerning that walking into a web and not knowing if the spider has now taken up residence on your body somewhere. Makes me shiver to think about it!
This is truly an amazing little creature, but I have never seen it that I know of.Guess I need to get my eyes looking closer. I know when I find a bite I wish I knew who it was, but never see them either.Often when ariving on an early morning the prairie is silver with a mass of webs.
ReplyDeleteI bet you have seen them and just didn't realize it. They are small, and not very brightly colored. They all but disappear in their web...which is also kind of small. I find them in the gardens sitting on their web that is usually built across the paths in my flower beds. They also build in our timber. They really are incredible spiders.
ReplyDeleteShelly-When you write about a bug, it's usually the same day that I run into that same bug...and today, literally. I have no idea how many of those webs I walked into today. After the first one hitched a ride on my head, I learned to duck and weave while I was walked the trails. They are the most oddly shaped insect. I never knew why they had all those spines parked in their back ends. Thanks for the explanation. Those spiders sure are fearless. Most spiders run away but the spiny back spiders I ran into today all tried their hardest to capture me.
ReplyDeleteinteresting little spider, we don't have those here, is the back always in such an upright position??
ReplyDeleteThat is too funny Maria...I love it that your encounters are coinciding with my posts. I have so many of these little spiders in my yard it is crazy. I have two that have built webs about 10 inches apart on a bush right outside my front door. My experiences with them vary...sometimes they run and hide, other times they are very difficult to make move and they hold their ground (or web). I think they are such wonderful little spiders.
ReplyDeleteRoasted garlic, as far as I know they always hold their abdomen at that funny angle...at least each time I see them it is always with that upright appearance. What part of the country do you live in? These are common in the Eastern part of the country. There is another really neat species called an arrow-shaped micrathena. They are gorgeous reddish brown and yellow. I will post about them soon.
ReplyDeleteJust came off our Vermilion River trail in Central Illinois - we took the Gator with a cab on the trail because my daughter said she couldn't get through the trail for all the spider webs. Well, we got to the trail's end with over 50 of these liitle spiders (they're NOT insects!) all over the windshield - hope we didn't remove all of them from the woods! THANKS FOR THE INFO ABOUT THEM NOT BEING DANGEROUS.
ReplyDeleteThese spiders are definitely everywhere in the woods right now. The trail I walk is riddled with these spiders and their hives criss-crossing the path. It is unfortunate that so many fell victim to your windshield, but rest assured you didn't hurt the population at all.
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