Spiders

Overview:

Spiders are amazing creatures, having been part of human lore and mythology for thousands of years. Few creatures have the ability to evoke such fear, fascination, wonder, and even admiration as the spider does. Spiders are Arachnids not Insects however; they are similar to insects in that they have an exoskeleton and jointed legs, but that's where the similarity ends. All spiders have 2 body regions and 8 legs; insects have 3 body regions and 6 legs. Spiders do not have antennae, whereas insects have 2, also spiders do not have wings. Relatives of the spider include; ticks, daddy-longlegs, scorpions and mites.

Facts:

Spiders can be divided into two groups: hunting (sometimes known as wandering) spiders and web-building spiders. All spiders produce silk, but hunting spiders do not construct webs to capture food. Instead, they rely on their quickness and relatively good eyesight to capture prey. Web-building spiders construct webs in rather quiet, undisturbed places to capture their food. They live in or near their web and wait for food to come to them. They generally have poor eyesight and rely on sensing vibrations in their web to detect prey.

Spiders are considered beneficial because of the large number of insects they prey on, including a number of pest species. All spiders have venom and are therefore venomous. However, most spiders are harmless to people. They are shy and not aggressive, they will try to escape when confronted. Few spiders bite, even when coaxed; they're not looking at us as a food source. Fortunately, the bites of most spiders rarely break the skin and are less painful than an average bee sting

Identification:

Hunting Spiders

Jumping spiders are common spiders outdoors and indoors. They are active during the day and are often found around windows, ceilings, walls, and other areas exposed to sunlight. Jumping spiders are generally small to medium-sized (about 1/5 - 1/2 inch long) and compact-looking. They are usually dark-colored with white markings, although some can be brightly colored, including some with iridescent mouthparts. These spiders move quickly in a jerky, irregular gait. They get their name from their ability to leap on their prey, often jumping many times their own body length. Like most spiders, jumping spiders have eight eyes, of which the two middle eyes are particularly large. Jumping spiders have the best vision of spiders, seeing objects up to 8 inches away.

Wolf spiders are common spiders outdoors and are occasionally seen indoors. They are moderate to large-sized spiders (1/4 - 3/4 inch long). Wolf spiders are found on the ground or under stones in a wide variety of habitats, such as forest floors, grassy meadows, swamps, and bogs. Some even like to live underground. They commonly hunt during the day or at night when it is warm. Wolf spiders are dark-colored, usually brownish or grayish, with white markings.

Fishing spiders, also known as dock spiders, are typically seen around ponds, swamps, slow-moving streams, and nearby vegetation. They may occasionally be found indoors. Fishing spiders are the largest spiders in the Upper Midwest (1 inch long). With legs spread out, some fishing spiders cover as much as 4 inches. They are generally dark-colored, usually brownish or grayish, with white markings. Fishing spiders can "skate" across water and can dive underneath to capture prey. In addition to insects, fishing spiders can also catch tadpoles, small fish, and other small vertebrate animals.

Sac spiders (also known as two-clawed hunting spiders) are common spiders on foliage or on the ground, and can be commonly found indoors. They are small to medium-sized spiders (1/5 - 2/5 inch long) and are usually yellowish or light-colored. Although sac spiders do not construct webs, they do build retreats from silk. Outdoors, they usually roll up leaves into a tube, or may construct a retreat under stones. Inside buildings, sac spiders are found in retreats in a variety of places, including high up on walls near ceilings.

Crab spiders are common spiders outdoors, but are not usually seen indoors. They are small to medium-sized spiders (1/10 - 2/5 inch long) ranging in color from yellow or red to brown or gray. The first four legs of crab spiders are crab-like, being held out to the sides. They are also usually longer than the back four. Crab spiders can walk forwards, sideways, or backwards. While many hunting spiders actively pursue prey, crab spiders wait motionless and ambush insects that pass closely by. Outdoors, crab spiders are often found on flowers but are also seen on stems or leaves.

Gnaphosid spiders are common spiders outdoors. A specific gnaphosid spider known as a parson spider is occasionally seen inside. The parson spider is a medium-sized spider (1/2 inch long) with a brownish body and gray abdomen with a white band running down over half the length of its abdomen. Parson spiders hunt at night. During the day, they are usually found outdoors under stones or loose bark in silken retreats. Indoors, they hide under objects or in cracks or crevices.

Web Building

Comb-footed spiders, also known as cob- web spiders, are very common spiders outdoors and indoors. They are small to medium-sized spiders (about 1/8 - 3/8 inch long). Comb-footed spiders are usually brownish or grayish. They build irregular webs in many places, including wood and stone piles and in quiet areas of buildings, such as basements. A common type of comb-footed spider found indoors is the house spider (figure 7). It is grayish to brownish with chevron-like markings on its abdomen and a body length of over 1/4 inch.

Orb spiders are common spiders outdoors near buildings, but are usually not found indoors. They range in size from small to large (1/8 - 1 inch long) and are found in a variety of colors, with some being brightly colored. Orb spiders have large, swollen-looking abdomens, including some that are oddly shaped. They make the classic round, flat, wheel-like web familiar to most people. The black and yellow argiope spider also known as the garden spider is familiar to many. It is large (up to 1 inch long) and brightly colored black and yellow. Another common orb spider is the barn spider. It is large (4/5 inch long) and brownish in color.

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