Spiders have a lot to do in the fall as they need to mate, lay eggs, and die to leave the next generation to take over the world next spring. One of the many spiders that become active in the cold season is the pumpkin spiders (Araneus marmoreus) from the Araneidae family.
According to IFL Science, their vibrant orange abdomens make them look like a jack o' lantern on eight legs, perfect for the Halloween season. But is this just all a coincidence?
Pumpkin Spiders During Fall
Pumpkin spiders are also known as European grade spiders or a cross orb weaver that was introduced to the country from Europe but are relatively harmless species to the ecosystem despite their spooky appearance.
Females of this spider species sport the more festive pumpkin attire with their large abdomens, while males are only half their size. But they come in two colors in which the nominate variety is pumpkin-orange in color, while the pyramidatus variety has dark spots near its rear and a paler abdomen.
Sura Jeselsohn, a natural history writer, wrote in the Riverdale Press that she became curious about the pumpkin spiders when she come across large webs a few years ago that seemed to proliferate as the weather turned cooler. As she checks them every day, she noted that the webs also become bigger, until she saw glistening black eyes looking back at her.
She sought information from the state Department of Environmental Conservation and found that the spider she was referring to was a pumpkin spider. She said that it probably got its nickname from its plump abdomen or because they are common around the Halloween season.
According to a paper in Bruce Trail Conservancy, adult pumpkin spiders are active from the middle of summer until the first frost. They breed and start to lay eggs in the fall in special egg cocoons that contain hundreds of eggs that will hatch in the spring. Then the young go on through several stages of molting until they emerge as adults in Summer. The cycle then repeats in one year.
Orb Weavers Introduced Vertical Webs to Easily Catch Their Prey
Pumpkin spiders are a type of orb weavers that produces silk webs. SFGate reported that orb weavers were known to have introduced vertical webs to better intercept flying insects, which is an upgrade from the horizontal webs that earlier spiders make. They also make up the 40,000 known species of spiders.
They use three kinds of silk in which each one of them comes from different glands. Then, a fourth gland coats a "capture spiral" that makes the web sticky to hold its prey.
Orb weavers start making their webs with a bridging thread and drop them from a height where the spider pulls it tightly, crosses it, and reinforces it with thicker silk. Then a Y-shaped connection becomes the web's hub where framing threads were built. Some orb weavers species add a zigzag stabilimentum that camouflages the web and attracts prey by reflecting ultraviolet light.
But insects are not the only ones who fall prey to those silks. Hummingbirds also find themselves entangled and exhausted in them, although female hummingbirds also weave spider silk into their nests.
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