INDOOR SPIDERS OF NEW ENGLAND - Pest Control - Online Resources - Environmental Health & Safety
Indoor Spiders of New England
Introduction
Spiders have two body regions; the cephalothorax (the first body section with head and legs), and abdomen. All spiders also have 4 pairs of legs, fangs and venom, 6 or 8 eyes* and the ability to make silk. Spiders do not have antennae, but their short first pair of legs (called pedipalps) may superficially look like antennae. One difference among spider groups is in the manner of prey capture. The most familiar “web spinner” spider capture technique is to spin a silk web, and wait and pounce on prey, usually insects, after they are caught in the web. Another group of spiders actively hunts down their prey. Prey is grabbed with the fangs and injected with venom, and silk may be used to subdue the prey. Most of the venomous spiders in the United States do not spin large complex webs; instead they depend on strong venom to incapacitate prey. Of the 3,000 or more spiders in the United States, only a few enter homes on a regular basis. It is these indoor spiders that are the subject of this web based report.
*with the exception of 2-eyed spider groups not found in New England
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| Cellar Spider | Hackled Band Weavers | Jumping Spiders |
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| Yellow Sac Spider | Grass Spider | Woodlouse Spider (male) |
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| Black Widow Spider | Brown Recluse | Hobo Spiders |
Identification
The Hackled Band Weavers
Family Amaurobiidae
Callobius bennetti
Normally found under rocks, logs and occasionally in nooks and crannies of cellars and homes. This spider can be found out in the field at night waiting to ambush prey. Not poisonous to humans. The females can be as large as three-fourths of an inch. The cephalothorax is brown or black but the abdomen is variegated with a dorsal series of yellowish chevrons forming a band. This spider spins a large irregular sheet web in dark, moist areas, often against a vertical surface. The spider spends most of its time in this silk retreat.
The Woodlouse Spiders
Family Dysderidae
Dysdera crocata
Normally found during the day under rocks, logs (including woodpiles) and other debris. In captivity they will eat any prey but in the wild prefers woodlice or pillbugs (isopods), thus the specialized long, divergent chelicerae and fangs that are strong enough to penetrate the tough cuticle of a woodlouse. A very cool spider, this species is easy to identify because of its red cephalothorax and yellow abdomen. They have six eyes clustered in a circle. Largely nocturnal, this species occasionally can be seen wandering on the lower levels of buildings and in the basements of homes. Its bite can be painful but the venom does not cause serious medical problems. Females do not make webs, instead they building a silken sac-like retreat in which they rest, molt and lays eggs.
The Sac Spiders
Family Miturgidae
Cheiracanthium mildei
Normally found indoors behind curtains, along ceilings and upper portions of walls, often hides under clutter or in cracks during the day. The abdomen is a shade of pale yellow, and the sac spider may superficially resemble a brown recluse in size and shape. Actively hunts at night and makes a white tubular retreat (the sac) which may be found indoors with our without the spider. Cheiracanthium spiders can be responsible for a very painful bite that may create an area of dead skin.
Family Clubionidae Sac spiders or two-clawed hunting spiders
Trachelas tranquillus
T. tranquillus is another of the sac spiders that may be found in homes. It ranges from New England and adjacent Canada, south to Georgia and Alabama and west to Kansas and Minnesota. Outdoors, they are found in the same places as yellow sac spiders (see above) and also construct silken retreats, within which they hide diurnally. Most occurrences of T. tranquillus in homes coincide with falling temperatures in autumn. They do not, as a rule, establish reproducing colonies in homes.
The female is 7-10 mm in length; the male is 5-6 mm. The chelicerae and carapace are thick, hard, and reddish-brown, covered with what appear to be tiny punctures. The abdomen is pale yellow to light gray, with a slightly darker dorsal stripe. The front pair of legs is darker and thicker; the other three pairs become increasingly lighter and thinner toward the last pair.
These spiders prefer warmer and drier habitats. They can be found at the bases of plants, on fences, inside rolled leaves, and under stones and boards. Mature females are often collected while they wander about in homes during the autumn. Males mature and mate in midsummer, and each female will deposit a pure white egg sac containing 30-50 eggs in September or October. A common oviposition site is under loose tree bark. A peculiar trait of this spider is its reported tendency to scavenge on dead spiders and insects.
The broad-faced sac spider has been reported to produce a painful bite. There are records of severe secondary infection associated with the bite, which may be the result of the spider's propensity for feeding on dead arthropods. Typically, the bite produces a painful erythema, not unlike a bee or wasp sting. Individuals who are sensitive to arthropod venoms may exhibit a more severe and possibly systemic reaction.
The Wolf Spiders
Family Lycosidae
These are hairy spiders with long hairy legs, and are active hunters. These hairy looking spiders may be confused with the much larger and unrelated tarantula spiders, which are not found in New England. Wolf spiders are active night hunters and do not normally come into contact with man, although they are easy to find scurrying around outdoors. Many species of wolf spiders have eyes that reflect in the dark when exposed by a flashlight.
The Cellar Spiders
Family Pholcidae
Pholcus phalangioides long-legged cellar spider
These extremely long-legged, thin light brown spiders are often found in cellars and basements. They rest during they day in dark areas, clinging to webs covered with dust. They will quickly move when disturbed and can reach a span of more than 3 inches when adult. This is the most common cellar spider throughout the United States. They are also known as “daddy-long-legs spiders” because of their resemblance to daddy-long legs, which are not spiders.
Jumping Spiders
Family Salticidae
Salticus scenicus Zebra Jumping Spider
Found resting on window sills, running quickly and jumping on flat surfaces, or occasionally lowering itself on a dragline. These brightly colored small spiders can jump forwards, sideways and backwards with equal ease. They are non-toxic. They have three rows of eyes, with the central pair often greatly enlarged, providing a wonderful panoramic spider view of the world.
Phidippus audax Daring or Bold Jumping Spider.The majority of P. audax specimens are black with three white spots. Note the iridescent scales and flat (without gloss) black patches on the abdomen.
Platycryptus undatus Jumping spider
Its usual habitat is on tree trunks and man-made structures (houses). The males have a rusty band under the eyes; the female has a pale or white band.
The Cobweb Spiders
Family Theridiidae
Achaearanea tepidariorum Domestic House Spider
The cephalothorax is yellowish brown and the abdomen is dirty white to brown with indistinct brown/gray markings on the posterior half. The legs of the male are orange, and legs of the female, yellowish. This very common spider makes its web in the corners of rooms and in the angles of windows. This spider tends to stay in its irregular cobweb and may live for a year or more.
The Funnel Web Spiders
Family Agelenidae
Agelenopsis species (Grass Spiders)
Grass spiders weave sheet webs that have a funnel shelter or retreat on one side. The web is not sticky, so these spiders make up for that fault by being able to run very rapidly. Grass spiders are identified by the arrangement of the eight eyes in three rows or 2 highly forward curving rows. The top row has two eyes, the middle row has four eyes, and the bottom row has two widely spaced eyes. They are generally brownish or grayish with light and dark stripes near the head. They have long spinnerets and are moderate-sized (3/4 inch long). Their webs are commonly built on the ground, around steps, window wells, foundations, and low shrubs. These spiders are common outdoors and are occasionally found indoors. Their funnel-shaped webs may be seen in cracks such as in tree bark, and the spiders themselves are found, not uncommonly, in bathtubs.
Tegenaria domestica the barn funnel weaver spider
This is another hair spider, but it can be distinguished from the wolf spider by its long spinnerets. Common in houses in the Northeast, and is widely distributed in temperate and tropical parts of the world. The web of this spider was used by pioneers to staunch the flow of blood.
Scytodidae Spitting Spiders
Scytodes thoracica Common spitting spider
A small, light colored spider with thin legs, and under close inspection, has a pronounced humped cephalothorax (prosoma). The enlarged prosoma holds glands which contain sticky venom which is sprayed out over the prey and which acts like a sticky net that traps and subdues its victims. The spider then bites its prey with very small, weak fangs. It is a six-eyed spider. At close inspection, it has a pretty pattern somewhat like a leopard.
Theridiidae
Steatoda grossa false widow spider
This spider is dark brown to black, shiny round, but without the red hour-glass spot found in black widow spiders. They are often mistaken for black widow spiders.
Family Pisauridae Fishing Spiders
Dolomedes tenebrosus
Nursery-web spiders are similar to the larger wolf spiders in size, shape, and coloration. Species in the genus Dolomedes are called fishing spiders because most live near water and have been reported to catch small fishes and aquatic insects from the water as they walk on the surface. Dolomedes tenebrosus is more frequently associated with wooded areas (it would be more accurately classified as a tree-dwelling spider) and is a common household invader in these locations. It occurs from New England and Canada south to Florida and Texas.
Although a large spider such as D. tenebrosus is able to bite humans, it is a shy spider that will run from people. Bites are typically no more severe than a bee or wasp sting. Exceptions do occur for individuals who are sensitive to spider venoms.
Genus Meta- Cave Orb Weavers or Common House Spider Achaearanea tepidariorum
Highly Venemous Spiders
Spiders can control the amount of venom they eject into a bite. And only a few spiders produce venom virulent enough to be harmful to man. Here are images of the more venomous spiders in the United States.
Black Widow Spiders
Familiy Theridiidae
Latrodectus species
All five species of black widow in the United States are known to cause illness to man. The venom attacks the nervous system, and the victim often suffers from abdominal pain, tightness of the chest, and contractions of muscles in the legs. There may be increased severity of symptom including increased blood pressure, rise in body temperature, profuse perspiration, nausea, and a few may die within 14 to 32 hours due to asphyxia preceded by convulsions.
The web is irregular and built close to the ground with a funnel-shaped retreat in a dark area. Some females may live for up to three years. The most common black widow (L. mactans), has a red hourglass shape on the underside of the shiny black abdomen. This spider is found in specific areas in southern New England.
Violin or Recluse Spiders
Family Loxoscelidae
Loxosceles species
The bite of this spider may be painless at first. Six to eight hours later, there may be tenderness and a slight stinging sensation. Twelve to 24 hours later the victim may experience malaise, chills, fever, and nausea. On the second to seventh day, skin loss followed by extensive necrosis results. Ulceration develops and if there is kidney or liver damage, the victim may die.
These spiders construct small irregular silk retreats indoors in dark corners, in trunks, and under stored objects. They are not native to New England but may be transported from warmer area in luggage etc. These spiders may live indoors for several years. The spider has 6 eyes in 3 pairs, rather than the usual 8 eyes. The general color is yellowish brown, with a dark violin mark on the cephalothorax. The legs are long and covered with short stiff hairs.
Hobo Spiders
Family Agelenidae Funnel web weavers
Tegenaria agrestis
These spiders are not found in New England, they are more common in Washington State and Idaho. They make a funnel web leading into a crevice in the ground. These spiders are difficult to identify, it is best to send them in to a specialist for identification.
Control of Spiders
All indoor spiders in New England can be controlled using a combination of non chemical control measures. Put out sticky survey traps that will capture and eliminate some spiders while at the same time, indicating the source of the infestation. Then try to seal off the source by using stuffing, caulking, foam sealant or other technique. Often spiders crawl under exit doors to the outside that need to have better weather stripping installed. Other routes of entry around pipes through the floors can be sealed with clear silicone caulking.
The use of a vacuum cleaner can be of value in sucking up small spiders from under furniture and in other hard to reach places. Be sure to empty the bag after vacuuming in a location outside of the building. Vacuuming will also pick up small mites and other insect parts which are very difficult to see with the naked eye.
If you are seeing a large number of spiders indoors, check window frames on the inside and the outside to make sure they are spider tight. Look for excessive moisture conditions which will attract other insects that become spider prey. By eliminating miscellaneous insects, you are minimizing food for spiders. Finally and very importantly, get the spider identified so that by understanding its biology and food source, you can more effectively control its numbers indoors.
