Effective Spider Extermination
PestLock is your go-to source for spider control in these NW Oregon and SW Washington cities. Our local exterminators will efficiently identify and remove them from your residential or commercial property with proven pest control techniques that are safe and effective. Call us today to learn more.
More than several thousand species of spiders exist in the United States. Two of the most common venomous and more common household spiders found in the Pacific Northwest include the black widow and hobo spider. While all spiders produce venom that is poisonous to their normal prey, these spiders have a lethal bite that can cause serious side effects to humans. Please seek medical help immediately for bites stemming from either of these species.
Female Black Widows
The female varieties of this species are 1.5 inches in diameter and jet black with red or yellow markings on the underside of the abdomen that resemble an hourglass. The much smaller males are light-colored with white or yellow stripes on their abdomens. In general, black widows are not particularly aggressive, and they rarely cause bite injuries unless disturbed. However, since the venom is toxic to the nervous system, a small bite may lead to systemic effects, including convulsions and even death. Most bites occur when reaching under furniture or lifting objects where a spider is hiding.
These spiders are nearly 2 inches in diameter with long, hairy legs and chevron-shaped abdominal markings. They also move very fast. Females generally have larger abdomens than males. Reported bites from this spider are relatively rare, despite its aggressive nature. However, when bites do occur, the venom is necrotic, causing open, localized wounds that are slow to heal.
Brown Recluse Spiders
Brown recluses are about 1 inch in diameter and yellow to dark brown in color. They have a distinctive violin-shaped mark that runs down the top of their head and thorax. They are not particularly aggressive and usually retreat to cover when disturbed. Most bites occur when a person traps or crushes the spider by rolling on the spider while asleep in bed. Within eight to 12 hours, the pain increases in intensity and after a few days, a large sore appears. The sores heal very slowly and often leave a scar.
Other species that do not pose as much of a threat to humans, but are also common, include:
- Funnel Weaver
- House Spiders
- Ground or Wolf Spiders
- Jumping Spider
- Crab Spider
- Sac Spider
- Orb Weaver or Garden Spider
- Cat-faced Spider
- Cellar or Daddy Long-Leg Spider
- Harvestman Spider
- Fishing or Nursery-Web Spider.
Most spiders are seldom seen, except from late August to early October when they are more active. They usually live in neglected areas, including attics, crawlspaces, and basements. They are also often found behind and under furniture, bookcases, or appliances, and in corners and cracks between boards.
They produce silk that is secreted as liquid and then hardens in the air. Different types and textures of silk may be used to construct snares and webs to capture prey as well as egg sacs, draglines, and ballooning threads. Draglines and ballooning threads are used by spiders to move and/or swing from one location to another. After climbing to a high point, some spiderlings will release ballooning threads to disperse themselves to new areas. The young are then seen sailing through the air on wind currents that have caught the ballooning threads. Depending upon the species, spiders lay eggs within a silk egg sac that is often ball-shaped and either hidden in the web or carried by the female. They may produce several egg sacs, each containing several hundred eggs, or as many as 3,000 eggs in a series of several sacs over a period of time. Eggs may hatch a few weeks later, or they may not hatch until the following spring. After molting four to 12 times, all spiders reach adulthood in about a year. Most spiders live either one to two seasons, and some may die as soon as they mate or produce egg sacs.
Black Widow Spiders
In the Pacific Northwest, black widow spiders primarily thrive in dry, undisturbed areas including firewood piles, old lumber, crawlspaces, bales of hay, and other similar areas. When found in homes, they are usually under appliances or heavy furniture. Female black widows spin silken webs that are usually in protected places under stones, house steps, decks, ground trash, or an overhanging embankment. The webs are irregularly shaped with strands running in many directions. They also hide during the day and hang upside-down in their webs at night. From May to October, female black widows lay and guard their egg sacs until the young are ready to hatch. During their one- to two-year lifespan, the females will produce several egg sacs, each containing several hundred eggs.
These spiders are typically found in and around houses, barns, and sheds. These spiders create webs similar to those of funnel weaver spiders, residing at the narrow end of their webs, ready to pounce on their prey. These include flies, cockroaches, crickets, earwigs, silverfish, pill bugs, various beetles, and other spiders. The web is not sticky like that produced by other spiders, but it traps insects that are unable to navigate on the surface. The life cycle of hobo spiders is seasonal, with eggs hatching in April or May. As males mature, they leave their webs in search of females for mating, and then they die. Females will lay their egg sacs and also die. Eggs don’t hatch until the following spring.
Brown Recluse Spiders
Brown recluses are usually found indoors in bathrooms, bedrooms, closets, garages, basements, and cellars. They also prefer to reside in and around ductwork or registers and attics. Their webs are off-white to gray in color, and they are often found in secluded locations, such as seldom-used shoes and clothes. Females will lay from one to five egg sacs, each containing 40-50 eggs, during her lifetime. Spiderlings emerge in about 30 days.
Funnel Weaver Spiders
These are primarily seen in late summer when morning dew makes their webs in lawns more visible. They are about half an inch long and have various marking in shades of gray, brown, white, black, and dull yellow. Like the hobo spider, these spiders are members of the funnel-web group. They hide at the narrow end of their funnels and wait until they feel the vibration of an insect crossing the web. When this happens, they dash out, bite the insect, and carry it back to the narrow end of the funnel. Females deposit their disc-shaped egg sacs in crevices, then die. They are sometimes found still clinging to the egg sacs even after death.
These spiders are 1/3 of an inch long and larger than the males. They are gray to brown in color and have a mottled, globular abdomen that has several dark stripes on the upper side. They prefer to spin their webs in dark corners of moist rooms and hang upside down in the center of an irregular cobweb. The sticky threads entangle many insects, which are then bitten and depleted of blood. Webs become dust-covered when abandoned. Fertilized several times during her lifetime, the female will produce up to nine egg sacs, each containing 200 or more eggs. Hatching occurs in about eight days, but the young will stay within the sac until after the first molt. They are also cannibalistic, eating one another, and may take several months to mature.
Female Ground or Wolf Spiders
This variety is large, about 1/2 an inch long, and hairy. Their bodies are covered with shades of brown, black, gray, white, yellow, orange, or green. Many have a stripe or pattern the length of the first body segment and sometimes on the second. They run rapidly after prey, and they are often confused with tarantulas. They are nocturnal and may wander indoors in late summer and fall when temperatures cool. They are usually found in cellars and basements. These hunting spiders do not construct webs. Rather, the large, globular egg sac is attached to spinnerets under the abdomen of the female. Upon hatching, the spiderlings will climb onto their mother’s back and stay there several days before dispersing. They will not establish themselves indoors and they are not aggressive, but they may bite if handled or mistreated.
These spiders are about 1/2 an inch long or less, and they are stocky with short legs. The legs enable them to jump several times their own length. Their movements are quick with short, sudden jumps. They are also hairy with bright colors that resemble iridescent scales. Some are black with spots of orange or red on the top surface of the abdomen. Others are brownish-gray and yellow with white markings. Two of their eight eyes are very large on the face and their eye color can be changed as needed. They depend on their vision and leaping abilities to catch prey, especially flies. Some may bite humans. They are active during the day and like sunshine. After mating, the female constructs a silk cocoon for her eggs and guards it.
This variety walks forward, backward, and sideways like a crab, hence their name. Their bodies are compressed from top to bottom, giving a stocky appearance, and the first two pairs of legs are larger than the last two pairs. They are about 1 inch long or less. Males are smaller than females and have much longer legs. Many have “horns” or ornaments on the head or abdomen. Some crab spiders mimic the colors of the flowers upon which they rest to ambush their prey. As such, they come in bright colors of red, yellow, orange, white, and/or green. Others will inhabit trees or hunt along the ground and come in shades of gray, brown, or black. They do not make webs, but females lay their eggs in a sac and die before the eggs hatch.
These spiders are sometimes called two-clawed hunting spiders because they have two claws at the tip of their legs. They are suspected of being responsible for most indoor bites, but no deaths have been reported. Since their venom is cytotoxic, only the tissue around the bite site is affected. These hunting spiders do not build webs, but they construct flat, tubular sacs that are open at both ends. The sacs are found in rolled leaves, crevices, or under loose bark. These light green to yellow-white spiders have a dark strip on the front portion of the upper-midline of the abdomen, which is flat. Females are about 3/4 of an inch long, whereas males are about 1/4 of an inch long. Their eight eyes are similar in size and neatly arranged in two rows across the front of the face. The jaws are brown, and the front legs are longer than the rear. Females place their white, paper-like egg sacs under a stone, in wall voids, or the upper corners of rooms. Sac spiders roam ceilings and walls to seek prey. The indoor population will increase as the weather cools and food sources decline in the autumn.
Orb Weaver or Garden Spiders
The traditional circular, flat, wheel-like webs in which flying insects are trapped are constructed by orb weavers or garden spiders. These large, elaborate, and beautiful webs are found in gardens and tall vegetation, especially in late summer and early autumn. Since these spiders have poor vision, the prey is primarily detected by feeling the vibration of and tension of the threads in the web. They will then bite their victim and quickly wrap it with silk while spinning with their legs. The prey is then carried to the center of the web or to the corner where it is eaten. Inedible items are cut from the web and dropped to the ground. Female orb weavers produce egg sacs containing several hundred eggs, then they die. Eggs may hatch soon after, or they may not hatch until the following spring. Many adults are large, and some have abdomens with odd features, such as pointed spurs and conical tubercles that come in a variety of colors including black, yellow, orange, red, white, brown, and green.
A common garden spider is known as the black-and-yellow garden spider. It has silver hairs on the back of its front body section and a large abdomen marked in black and bright yellow or orange. The front legs are sometimes black, and they may have a short band of orange on them. This spider is about 1 inch long and hangs upside down in the center of the web. Despite its formidable appearance, they are not considered dangerous, but they can bite if handled or mistreated.
One of the most common but unusual spiders encountered in the Pacific Northwest is the cat-faced spider. Full-grown females can be quite large, and they have a combination of odd projections on the abdomen as well as dark indentation markings that resemble the ears and eyes of a cat, hence their name. Despite their large size and bizarre appearance, they are harmless to humans. They tend to create webs near lights and in corners along the outside of buildings.
Cellar or Daddy Long-Leg Spiders
These spiders have slender legs that can grow up to two inches long. Their whitish-yellow to pale gray bodies are about 1/3 of an inch in length and their eyes are close together. They are commonly found in barns, cellars, and damp warehouses. Many hang upside-down in a loose web in dark corners of homes or cellars. Males and females live together, and when alarmed will shake the web violently. The female carries the round egg sac in her jaws.
These spiders are not technically classified as spiders, yet they resemble cellar or daddy long-leg spiders. They are tan to brown in color, and they have an oval-shaped, compact body with extremely long, slender legs. They may be found in gardens and outdoor buildings. Occasionally, they are found in homes, feeding on plant juices, dead insects, and some live insects.
Fishing or Nursery-Web Spiders
This species resembles wolf spiders due to their large size and 3-inch leg span. They have excellent vision and may sit quietly for hours with their legs spread out on vegetation or boat docks, or hunt actively in vegetation. They feed on aquatic insects and sometimes small fish. Most can run across the surface of the water and if chased, and they will dive into the water, staying submerged for some time. Many live near lakes and streams, but occasionally they can be found indoors in moist areas. Females carry huge egg sacs in their jaws, which are located under their bodies. When hatching time is near, they will tie leaves together with silk around the eggs sacs and stand guard. Young spiders will leave the nursery about one week later.
Customer Preparation for Spider Control Treatment
- Use a strong suction vacuum cleaner with proper attachments to collect and destroy webs, egg sacs, and spiders.
- Use a dust mop, stiff broom, and dustpan as needed to discourage any new spiders.
- Move and dust behind and under furniture, stored materials, wall hangings, and corners of ceilings as often as possible.
- Eliminate other household pests such as flies, ants, and cockroaches as they attract spiders.
- Seal or caulk cracks and crevices around windows and doors.
- Install tight-fitting screens as needed to prevent spiders from entering the house from outside.
- Control excess moisture and humidity by keeping basements, crawlspaces, and porches as dry as possible.
- Clean up outdoor woodpiles, trash, rocks, compost piles, old boards, and other debris, especially around the foundation.
- Use a hose with high-pressure water to knock down and destroy webs, egg sacs, and spiders on the outside of the home.
- Use yellow or sodium vapor light bulbs around the outside entrances to reduce night-flying insects, which attract spiders.
Customer Expectations Following a Spider Control Treatment
Spiders will act abnormally prior to death. Either more or less will appear, climbing up walls to flee from treatment. Some may even appear from crawlspaces to die. Expect additional activity within the next 30 days as spiders continue to track through the residue. Our products will not only kill spiders on contact, but it will act as a repellent by leaving a long-term residue that outlasts their life cycles.