Description: There are many genera of Wolf Spider, ranging in body size from less than 1 mm to 5 inches. They have eight eyes arranged in three rows. The bottom row consists of four small eyes, the middle row has two very large eyes, and the top row has two medium-sized eyes. They depend on their eyesight, which is quite good, to hunt. Their sense of touch is also acute. Because they depend on camouflage for protection, they do not have the flashy appearance of some other kinds of spiders. In general their coloration is appropriate to their favorite habitat.
Biology: Wolf spiders are unique in carrying their eggs along with them in a round silken globe, or egg sac, which they attach to the spinnerets at the end of their abdomen. Also unique to wolf spiders is their method of infant care. Immediately after the little spiders hatch and emerge from their protective silken case, they clamber up their mother’s legs and all crowd onto her abdomen.
Habits: Wolf Spiders are nocturnal and will be out hunting for food, making it easier to find them. They are robust and agile hunters with good eyesight. They live mostly solitary lives and hunt alone. Some are opportunistic wanderer hunters, pouncing upon prey as they find it or chasing it over short distances. Others lie in wait for passing prey.
Although their reputation would lead one to believe otherwise, the bite of the wolf spider is not fatal. Wolf spiders also do not bite unless threatened or provoked. In most cases the wolf spider will first retreat or rear up on its legs, exposing its large fangs.
Description: The keys to the identification of the Hobo Spider will be the eye arrangement and the pattern of darker “fishbone” or chevron stripes on their upper abdomen. The 8 eyes are in two parallel rows of 4 ocelli across the front of the cephalothorax, with both rows forming straight lines. This has become a very common spider in homes especially in basements, crawl spaces, and other lower areas of the structures.
Biology: It is one of a small number of spiders in North America whose bites are generally considered to be medically significant. Although this species of spider has a reputation for aggressiveness, they will normally avoid contact with humans. Most bites occur when the spider is accidentally crushed or squeezed by a human. The bite from the Hobo Spider appears to be capable of causing a fairly severe necrotic wound. Untreated, the wound could take up to six months to finally run its course and begin to heal, but with the proper treatment the effect should be greatly reduced.
Habits: It is a member of the genus of spiders known colloquially as funnel web spiders. Individuals construct a funnel-shaped structure of silk sheeting and lie in wait at the small end of the funnel for prey insects to blunder onto their webs. It can be a fast running and fairly aggressive spider, biting with less of a reason than most other hunting spiders need.
Description: Brown Recluse spiders have 6 eyes, arranged as 3 pairs in an arc across the front. Most spiders have 8 eyes, and no other groups have the eyes placed in the same pattern as the Brown Recluse spiders. The name “violin” or “fiddleback” comes from the dark violin-shaped pattern on the top of these spiders.
Biology: Their kind of venom is essentially a digestive venom, and once injected into a human it remains in the area of the bite for a very long time, killing and digesting the cells in that area. The result can be an open, ulcerating sore that cannot seem to heal, opening the pathway for an infection that could spread to other parts of the body.
Habits: Recluse spiders build irregular webs that frequently include a shelter consisting of disorderly threads. These spiders frequently build their webs in woodpiles and sheds, closets, beds, garages, cellars and other places that are dry and generally undisturbed. They seem to favor cardboard when dwelling in human residences, possibly because it mimics the rotting tree bark which they inhabit naturally. They also have been encountered in shoes, inside dressers, in bed sheets of infrequently used beds, in stacks or piles of clothes, behind baseboards and pictures, and near sources of warmth when ambient temperatures are lower than usual. Human-recluse contact often is when such isolated spaces are disturbed and the spider feels threatened. Unlike most web weavers, they leave these webs at night to hunt. Males will move around more when hunting, while the female spiders tend to remain closer to their webs.
Description: The body of the female black widow is about ½ inch long, glossy with a nearly globe-like abdomen. The abdomen has two triangular red spots on its underside arranged in such a way that the spots look like an hourglass.
Biology: Black widow spiders lay their eggs in silken sacs which they protect in their nests. A female produces from 6 to 21 sacs during her lifetime, each containing 185 to 464 eggs. The young spiderlings remain in the case until the second molt. They live in the vicinity of the nest for two to three weeks before producing long threads of silk that help them float away, much like kites float. Females live up to three years and males approximately 180 days.
Habits: Black widows are shy, preferring to build their webs in a dry protected location where their prey is likely to travel. Outdoors they can be found among rocks and wood piles, under decks, in hollow stumps, rodent burrows, beneath benches, etc. They prefer basements, crawls spaces, and garages in structures as well as other protected areas. Females often eat the males after mating, thus giving them their rather morbid name. Females produce a neurotoxin poison, and do bite if disturbed or handled roughly. Each year several deaths are attributed to the bite of black widow spiders as a result of anaphylactic reactions. However, in most cases, the bite is no worse than a wasp sting.
Description: House spiders are the most frequently found in human dwelling places. Some of the more prevalent house spider species include the common house spider, the domestic house spider, the aggressive house spider and the brown house spider. Their exteriors and sternums are yellow or brown in color. Their abdomens are gray and marked with white, while their legs are brown and darkly banded. Males are smaller than females, measuring only four millimeters in length as opposed to the female’s eight.
Biology: Female common house spiders deposit as many as 250 eggs into a sac of silk. These sacs are often brown in color and are flask-like in shape. Females produce up to 17 of these sacs during a lifetime, resulting in more than 4,000 eggs. Within a week, spiderlings hatch and begin to undergo a series of instars. The first instar takes place inside the egg sac. Spiderlings in the first instar do not nourish themselves, while those in the second instar consume premature eggs. After hatching, air currents disperse surviving spiderlings on threads of silk. This process, known as ballooning, allows spiders to populate habitats far from their origin. Adult spiders may survive for more than a year.
Habits: House spider webs are typically funnel-shaped and can be located in various places within a home, including windows, ceiling corners and above or beneath fixtures. House spider webs are large and constructed of thin silk threads.Â They serve both as dwelling places and as traps for prey. House spider prey is paralyzed by venom injection before being broken down by digestive juices. As a result, prey is liquefied to allow for consumption.
Description: As their name suggests, they are found outdoors and in gardens. Garden spiders are not aggressive and are more likely to retreat from than attack humans. However, in cases of extreme provocation, garden spiders may bite. Their bites are harmless to humans. They measure approximately one inch in length or larger and are often marked vividly in black and yellow.
Biology: The garden spider also uses its extraordinary sense of touch for mating, as males tap upon the webs of females to express their intent. Because males spend the mating season obsessively seeking partners, they typically die of exhaustion and malnutrition following fertilization.
In the fall, garden spiders lay their eggs in silken sacs that contain between 50 and several hundred eggs. The garden spider’s egg sac is relatively spherical. Covered in brown-colored silk, they are strong enough to withstand winds and attacks from most predators.
Young spiderlings overwinter within their eggs. In spring, they hatch and disperse. Female garden spiders die soon after laying their eggs and are not able to protect or assist their spiderlings.
Habits: Garden spiders are known as orb weavers due to their orb-shaped, delicate webs. Even garden spiderlings are capable of spinning these intricate structures without the assistance of mature spiders. The webs of garden spiders are notoriously strong, and may reach more than 12 inches in diameter. The garden spider uses its web to capture food. Although their eyesight is poor, garden spiders are extremely sensitive to vibrations along the strands of their webs. Positioning themselves at the center of their web, garden spiders hang upside down, jump on prey and paralyze it with injected venom
Description: The Jumping Spider family (Salticidae) contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders. Jumping spiders have good vision and use it for hunting and navigating. They are capable of jumping from place to place, secured by a silk tether. Adults rarely grow larger than one inch. Some common house jumping spiders appear black with white markings along the abdomen.
Biology: Jumping spiders are known for their swift reflexes and leaping abilities. These spiders are capable of leaping as high as 25 times their own size and as such, are extremely capable predators. Jumping spiders also possess impressive eyesight. When a jumping spider is moving from place to place, and especially just before it jumps, it tethers a filament of silk to whatever it is standing on. Should it fall for one reason or another, it climbs back up the silk tether.
Habits: Jumping spiders are known for their curiosity. If approached by a human hand, instead of scuttling away to safety as most spiders do, the jumping spider will usually leap and turn to face the hand.
Jumping spiders are a scopula-bearing spider, which means that they have a very interesting tarsal section. At the end of each leg they have hundreds of tiny hairs, which each then split into hundreds more tiny hairs, each tipped with an “end foot”. These thousands of tiny feet allow them to climb up and across virtually any terrain. They can even climb up glass by gripping onto the tiny imperfections, usually an impossible task for any spider.
Jumping spiders are active hunters, which means that they do not rely on a web to catch their prey. Instead, these spiders stalk their prey. They use their superior eyesight to distinguish and track their intended meals, often for several inches. Then, they pounce, giving the insect little to no time to react before succumbing to the spider’s venom.
Description: There are several species of Sac Spiders in the U.S., and for whatever reason they appear to be more inclined to bite people with less provocation. The bite from a Sac Spider is said to produce “instant, intense stinging pain”, followed by swelling, redness, and then itching at the site of the bite. There likely will also be a necrotic lesion formed due to the injection of the cytotoxin venom of these spiders, and it has been suggested that many times, when Violin Spiders have been accused of biting people in areas outside their range, it could be the sac spiders instead that are the true cause.
Habits: The spiders are very common in and around homes, and as hunters are likely to be found wandering throughout the house, where they could end up in clothing or beds. They are common in vineyards and are then easily transported within the bunches of grapes to other areas.