Nature Note #204: Web Heads
If you're as tall as I am (6' 3" to be precise) then you have no doubt experienced the horror, dread, and inconvenience caused by a spider web as it wraps around your head and neck. Frantically, you pull at its sticky strands with growing concern that the web's creator is just a short leap from your neck. Nine times out of ten, you're lucky enough to rid yourself of the nefarious net. The other day, I could have sworn I felt the spider moving in a panicked pattern up and down my neck as I tried to free myself from its trap. Later, I thought that maybe it had bitten off more than it could chew. That, of course, was a silly thought, though. If it really wanted to eat me, it would have to be massive and if that were the case, we humans would have bigger problems fighting an army of 6 foot long Shelobs.
There are three web weavers on the island that are frequently encountered: the golden silk spider (Nephila clavipes), the black and yellow orb weaver (Argiope aurantia) and the Micrathena spider (Micrathena spp.). All produce webs that can impede travel on the trails. As it turns out though, the longest lasting webs all seem to be out of the way, in between tree branches, along the balcony railings, and occasionally off of a telephone pole.
Golden silk spiders tend to be found in forests with their large (1-2 meter) webs draped above or across openings in the trees. They capture small prey such as moths, butterflies, and other flying insects. What is most striking about this species of spider is the size discrepancy between males and females. Sexual dimorphism generally plays to males being larger, louder, and more colorful, but this seems limiting as a guide considering 95% of all animal species alive today are invertebrates. In spiders, males can be up to 100 times smaller than the female and seem to exist only to eat, mate, and then potentially become a meal for their mates. Males therefore have evolved strategies to attempt mating without becoming lunch. Some males have been observed plucking the strings of the female's web in such a way that they "hypnotize" the females and can mate without incident.
Black and yellow orb weavers are the classic American garden spider. Also known as the writing spider and golden orb weaver, they can be found across the United States and southern Canada in open and semi open habitats such as fields, gardens, hedgerows, and forest edges. They are an excellent spider to learn to identify due to their black and yellow markings and unique web marking. The white patch that the spider sits on is known as the stabilimentum. The purpose of the feature is hotly debated and explanations range from an element to assist with camouflage, prey attractant, and even decoration. What I was surprised to learn was that a new web is built every day and that the old web is eaten! Talk about embracing impermanence!
Lastly, Micrathena are a unique genus of spiders with a large, spiky abdomen. These small spiders are harder to find than the other two and seem to be rather inconspicuous. Even their scientific name is combination of a Greek adjective meaning "small" and the name of the goddess Athena, referring to its arrow-shaped abdomen. The females, like most spiders are larger and more brightly colored, but also possess larger spikes on their abdomen especially in the species, M. sagittata. Their webs are recognizable by the hole in the middle, allowing the spider access to both sides of their construction. When disturbed, they frequently retreat to cover, moving swiftly away from the source of the violent vibrations.
Though they are intimidating in appearance, like most arthropods, they are more interested in their quest for hourly survival than to get involved in bothering humans. With that being said, it should be noted that pestering a spider with fingers or trying to hold it with bare hands might provoke it into biting. The species mentioned above do possess venom, but in quantities that will leave a red welt rather than a life threatening injury. Even if you were to be bitten by a black widow (Lactrodectus mactans) for instance, you would more likely suffer from latrodectism (symptoms include vomiting, muscle rigidity, and generalized pain) than a fatality.
If you want to learn more about specific spiders in your area, you should check out Spiders.us which has species bios that explain identification, range, habitat preference, season, web type, and life cycle, as well as detailed photographs of spiders to help you figure out the identity of your own mystery arachnid.
Before the first frosts wash over the land, we will still have time to enjoy these little architects for a while longer. After all, someone has to eat all of those bugs.
There are three web weavers on the island that are frequently encountered: the golden silk spider (Nephila clavipes), the black and yellow orb weaver (Argiope aurantia) and the Micrathena spider (Micrathena spp.). All produce webs that can impede travel on the trails. As it turns out though, the longest lasting webs all seem to be out of the way, in between tree branches, along the balcony railings, and occasionally off of a telephone pole.
Golden silk spiders tend to be found in forests with their large (1-2 meter) webs draped above or across openings in the trees. They capture small prey such as moths, butterflies, and other flying insects. What is most striking about this species of spider is the size discrepancy between males and females. Sexual dimorphism generally plays to males being larger, louder, and more colorful, but this seems limiting as a guide considering 95% of all animal species alive today are invertebrates. In spiders, males can be up to 100 times smaller than the female and seem to exist only to eat, mate, and then potentially become a meal for their mates. Males therefore have evolved strategies to attempt mating without becoming lunch. Some males have been observed plucking the strings of the female's web in such a way that they "hypnotize" the females and can mate without incident.
 |
| Golden silk spider in Croatan State Forest, Bogue, NC. Photo by me. |
Black and yellow orb weavers are the classic American garden spider. Also known as the writing spider and golden orb weaver, they can be found across the United States and southern Canada in open and semi open habitats such as fields, gardens, hedgerows, and forest edges. They are an excellent spider to learn to identify due to their black and yellow markings and unique web marking. The white patch that the spider sits on is known as the stabilimentum. The purpose of the feature is hotly debated and explanations range from an element to assist with camouflage, prey attractant, and even decoration. What I was surprised to learn was that a new web is built every day and that the old web is eaten! Talk about embracing impermanence!
 |
| Black and yellow orb weaver at Trinity Center, Pine Knoll Shores, NC. Photo by me |
Lastly, Micrathena are a unique genus of spiders with a large, spiky abdomen. These small spiders are harder to find than the other two and seem to be rather inconspicuous. Even their scientific name is combination of a Greek adjective meaning "small" and the name of the goddess Athena, referring to its arrow-shaped abdomen. The females, like most spiders are larger and more brightly colored, but also possess larger spikes on their abdomen especially in the species, M. sagittata. Their webs are recognizable by the hole in the middle, allowing the spider access to both sides of their construction. When disturbed, they frequently retreat to cover, moving swiftly away from the source of the violent vibrations.
 |
| Micrathena spp. at Stony Brook Millstone Preserve in Pennington, NJ. Photo by me. |
Though they are intimidating in appearance, like most arthropods, they are more interested in their quest for hourly survival than to get involved in bothering humans. With that being said, it should be noted that pestering a spider with fingers or trying to hold it with bare hands might provoke it into biting. The species mentioned above do possess venom, but in quantities that will leave a red welt rather than a life threatening injury. Even if you were to be bitten by a black widow (Lactrodectus mactans) for instance, you would more likely suffer from latrodectism (symptoms include vomiting, muscle rigidity, and generalized pain) than a fatality.
If you want to learn more about specific spiders in your area, you should check out Spiders.us which has species bios that explain identification, range, habitat preference, season, web type, and life cycle, as well as detailed photographs of spiders to help you figure out the identity of your own mystery arachnid.
Before the first frosts wash over the land, we will still have time to enjoy these little architects for a while longer. After all, someone has to eat all of those bugs.
 |
| Spiderwebs on a fall morning at Great Meadows, Concord, MA. Photo by me. |
"The difference between utility and utility plus beauty is the difference between telephone wires and the spider web." - Edward Way Teale
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