A tangled web
Halloween gives spiders a bad, scary image; now it’s time to focus on how amazing they are
Water hangs from a spider web in a field, in Silio, northern Spain, Sunday, Jan. 6, 2013. (AP Photo/Daniel Ochoa de Olza)
Many homes and yards were recently draped with white gauzy Halloween decorations that are supposed to look like cob webs. Often giant fake spiders are dangled from tree branches or light posts to add a tone of fear and mystery to the holiday of spooks and goblins. The image of the scary spider is one that clearly needs to be dispelled. Spiders aren’t creepy, they are amazing!
There are many different kinds of spiders; in fact at least 350 species live in New Hampshire. They share some common features, such as two body parts (the cephalothorax and abdomen) and eight legs. This is in contrast with insects, which have three body parts (head, thorax and abdomen) and six legs. Most spiders also have eight eyes, the size, shape and configuration of which can help identify the species. They all can make silk though not all of them spin webs. As predators they all use fangs to inject their prey with paralyzing venom. Fortunately, their prey is mostly insects and sometimes other spiders. Once immobilized, the prey is injected with digestive juices to liquefy the creature. Spiders, like baby humans, have no teeth, so their food is transformed into something the consistency of baby food to make it easier to consume.
The specifics of what spiders eat and how they catch their food illustrate the diversity of this group of animals. Orb weavers make intricate wagon-wheel shaped webs, which are particularly beautiful when dew drops cling to them in morning light. These webs are used for capturing insects, like a net strung between tree branches. The maker of the web hides on the edge until something is caught. When the spider feels the vibration of the trapped insect it will scurry across the web, inject its venom and begin to wrap the prey in a mummy-like enclosure. The weaver may eat the insect soon after the capture, or store it for later. It relies almost entirely on sense of touch to complete this process because its eyes are tiny and its eyesight is poor. Generally these spiders are most active at night.
The spinning of a web is an intricate, but predicable process. This nightly process takes about an hour to complete, and, because the silk is made of protein, the construction takes quite a bit of the spider’s energy. As a result, after the web has been used or damaged, the spider often eats the silk strands and thus recycles the material back into its body. Some of the strands on these webs are sticky and others are not. The spider knows the difference and will only walk on the non-sticky strands so it doesn’t get stuck in its own web.
However, not all spiders make webs. Some species use their silk for egg sacs, shelter, drag lines or transportation. A fine strand that is spun and hung down from a branch can be easily caught by the wind. This technique called “ballooning” enables spiders to be blown to a new location.
At this time of year some spiders are beginning to hibernate in silken sacs that they create beneath loose bark on a tree or a piece of fire wood. That is, if they hibernate. You may remember from Charlotte’s Web that orb weavers generally die in the fall, leaving their offspring to survive as eggs through the winter and hatch out in the spring.
In addition to the web spinners there are also hunting spiders that stalk their prey or build funnel type traps with their silk. These spiders, the jumping, wolf and crab spiders have much better eyesight than the web weavers and are active in the daytime.
Whatever way particular spiders are adapted for catching prey, they are definitely good to have as neighbors. They consume many insects that are considered pests around the home and garden. Unfortunately few people today hold spiders in high esteem as other cultures have done. From Greek myths to Native American legends, spiders have been symbols of beauty, patience, strength and creation. These are much more appropriate images than being icons of spooky nights, dark corners and un-kept homes.