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OUTDOORS FEATURE: Spiders --- more good than bad

Most spiders pose no threat to humans and should not be treated with fear and loathing. The black widow, above, is a familiar species and is one of only a few potentially dangerous spiders we are apt to encounter. (James Hybart III/Special to The Herald)

Most spiders pose no threat to humans and should not be treated with fear and loathing. The black widow, above, is a familiar species and is one of only a few potentially dangerous spiders we are apt to encounter. (James Hybart III/Special to The Herald)

Snakes, bats and spiders often conjure images of foreboding creatures and places. In most cases one would be hard-pressed to find any snakes or bats in or around his home. However, a quick search outside the door or in a few room corners can easily reveal a spider or two. Fortunately, as with snakes and bats, almost all the spiders we encounter on a day-to-day basis are completely harmless and are actually beneficial.

Outwardly similar to insects, spiders are not classified as such, but belong to a group of animals called arachnids, which also contains ticks, mites and scorpions. The most familiar difference between spiders and insects is the leg count. Insects possess six legs in three pairs while spiders have eight legs in four pairs. In addition to eight legs, spiders usually possess four pairs of eyes.

Worldwide, there are about 40,000 spider species with around 3,500 species in the United States. In Georgia the number of spider species is approximately 700, with more spiders likely to be discovered with future research.

Spiders are perhaps most famous for their ability to produce silk. Silk is produced by glands located in the abdomen. One type of spider silk may be used to build the egg sac, with other types used in different aspects of web construction.

Not all spiders build webs. Trapdoor spiders, for example, lie in wait inside their silk-lined burrows. Wolf spiders actively roam the ground in search of prey, and jumping spiders trail a silken anchor line as they hop along. Another use of silk allows young spiders to “fly.” Long threads of silk catch the wind and transport young spiders across the sky in a process called ballooning.

Everyone has almost certainly encountered one spider that regularly shares his home. Even the most well-kept house likely has a few common house spiders present. These harmless spiders, less than 1/2-inch, build their webs in seldom-disturbed corners of rooms and window sills. They go mostly unnoticed until their sticky webs collect dust and the carcasses of insects they have trapped and consumed.

Another very common spider in and around dwellings in the Southeast is the southern house spider. This spider is responsible for the familiar cobwebs that are found in attics and in sheds and barns. The intimidating appearance of a female southern house spider may be quite unnerving to some. Females are about 1 inch in length and are generally grey to black in color and are covered in fine hairs. As with many spiders, the male is much smaller. A male southern house spider is light brown and about half the size of the female.

While all spiders have venom, only three species in Georgia pose any real danger to people. One is the brown recluse. Fittingly named, the brown recluse spider is found in generally darkened, undisturbed areas under rocks, logs or other debris. Recluse spiders may also occupy human dwellings, in areas such as attics or undisturbed recesses of closets. This spider reaches a body length of 3/8-inch and the slender legs span the size of a quarter. Brown recluse spiders are also known as fiddle-back spiders for the dark violin patterns on their backs. They are easily confused with other brown-colored spiders, especially the male southern house spider. The bite of this spider may be of no consequence to some individuals while others may develop painful swelling and an area of tissue death that may take weeks to heal. All bites by brown recluse spiders should be taken seriously and medical attention should be sought.

Perhaps no spider is feared more than the black widow. Ironically, this spider is related to the common house spider and similar body shapes hint at this relationship. Adult females are shiny black with characteristic red hourglass markings on the underside of the abdomen. Body length is about 1/2-inch with legs reaching about 1 1/2 inches. Males are half the size of females and on occasion are killed and consumed by females after mating, thus giving the spider its common name.

Black widows are almost never found inside dwellings. A typical location for the black widow’s tangled web is a sheltered, undisturbed area behind a shed or garage. Black widows possess potent venom and a bite from the spider should always be considered serious although it is rarely life-threatening. Always seek prompt medical attention if bitten.

Also found in Georgia is the lesser-known brown widow. Found in similar habitats, the brown widow is smaller than the black widow. Adult females are generally grayish to brownish, and the abdomen and legs appear striped. A bold orange-colored pattern is evident on the underside. As with the black widow, the bite of a brown widow should be taken seriously.

A late summer walk in shaded woodlands, swamps, or even around the house may be interrupted by an unwelcomed encounter with the enormous web of the golden silk spider. Also known as the banana spider, this large, mostly yellow, inch-long spider constructs a web that may reach three feet across with anchor lines stretching even further. The tiny male may also be seen in the web as well. Though some find the spider fearsome in appearance, the golden silk spider is harmless and highly beneficial. Collectively, these and other spiders consume countless numbers of insects annually, including many harmful species.

Often underappreciated, spiders are but another part of the balanced natural world around us. They are extremely helpful predators and are important prey items for birds, lizards and a host of other animals. Only a few spiders are potentially dangerous while the rest may only inconvenience us with a little extra housework. Though confirmed “arachniphobes” may not be convinced, our fear of these eight-legged critters is totally unfounded.