The Pumpkin Spider
Marbled Orb-Weaver
By Sara Wright
Imagine my surprise when Coalie and I discovered an amazing looking spider who was using the side of the car as one of the attachment points for her web. It was a hot September morning at the Community Forest. We had been walking in the woods and had returned to the car for some water. I gently removed the large bulbous spider from the door, placing it in the nearest clump of goldenrod before taking a closer look. Wow, I was mesmerized by this rotund orange creature with such a fantastic pattern inked on her back. Immediately, I thought of the large black and yellow garden spiders and their webs that had so captivated my little brother and me as children.
I remembered them for good reason, it turns out, because, when I researched this spider, I discovered that Araneus marmoreus is one of the orb-weavers. The genus Araneus has about 1,500 species worldwide and is found throughout the Americas. Adult females have very large abdomens that are burnt orange to light brown with spots of yellow and incredible designs like the one I had seen.
The circular webs are composed of sticky threads arranged in spirals on non-viscous supporting threads. Marbled orb-weavers typically spin their webs at the top of vegetation, in low shrubs, tall grasses or fields in the early morning. Webs can also be found in trees, shrubs, in wooded areas and along the edges of streams as they are around here, although I have never met one of the weavers. The webs are oriented vertically, are open in the center, and have a signal thread near the center that stretches out to the spider’s hiding place to alert her when some creature has been captured. They may have poor vision but are extremely sensitive to vibrations.
“Wow, I was mesmerized by this rotund orange creature with such a fantastic pattern inked on her back.”
After spinning her orb, the spider hides curled up in a silken leaf retreat called a hibernaculum that is located on one side of the web. During the night she moves to the middle of the orb to capture prey. Moths, flies, mosquitoes, beetles, and aphids are favorite edibles – every gardener should invite these spiders in. Some of them eat their webs to recycle silk proteins before constructing a new one.
In the fall after mating (usually October) the female produces egg sacs in the shape of flattened spheres that contain hundreds of eggs that will winter over to hatch the following spring.
Adult spiders are not usually seen until mid-summer and may be visible until hard frost strikes. The males are so much smaller, and some don’t spin webs; they are rarely seen at all. The lifespan of these spiders is brief, with both females and males birthing in spring and dying in the fall. However, the eggs winter over and hatch as soon as winter turns the wheel.
Many species of wasps and birds prey on marbled orb-weavers. These fantastic looking spiders are shy and not aggressive. In fact, though fierce looking, they are quite harmless.
Ever since I saw my first marbled orb-weaver, I have been on the alert looking for more at Bucks Ledge Community Forest’s upper field without success, but now that my flower laden meadow has been cut, my narrow woodland paths will support these delicate webs as they do each year. I have yet to find one hibernaculum, but maybe it’s not too late to find one.
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