Spider Infestations in Calgary and What to Do About Them

Spiders (order Araneae) are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exception of air and sea colonization.

Information from Wikipedia.

There are over 35,000 described species of spiders worldwide, with about 3,000 occurring in North America. Many species of spiders are household pests. Wherever their food is available, spiders are likely to be found. All spiders are predators, feeding mainly on insects and other small arthropods.

Types of Spiders:

Black Widow Spiders

Black widow spiders are most recognized for the red hourglass shape on the back. Contrary to legend, female black widow spiders rarely devour the male black widow spider after mating.

black widow

Black Widow Spider Facts
Color | Black, with characteristic red "hourglass" on back
Legs | 8
Shape | Round
Size| 3/4" length; 3/8" in diameter
Antennae | No
Flying | No
Region | Canada and the USA

Black widow spiders spin their webs near ground level. They often build their webs in protected areas, such as in boxes and in firewood.

Black widow spiders are often found around wood piles and gain entry into a structure when firewood is carried into a building. They are also found under eaves, in boxes, and other areas where they are undisturbed.

The venom of a black widow spider is a neurotoxin and is used as a defense. Black widow spiders do not bite humans instinctively. The black widow spider bite can cause severe pain. Young children and the elderly are especially susceptible to a severe reaction to a black widow spider bite.

Avoid black widow spider bites by wearing heavy gloves when moving items that have been stored for a long period of time. Spiders often hide in shoes, so check shoes and shake them out before wearing. When spider webs are visible, use caution before putting your hands or feet in that area.

*Information from the National Pest Management Association

brown recluse spiders

Brown recluse spiders have a characteristic dark brown violin marking on their backs.

Brown recluse spider

Brown Recluse Spider Facts
Color | Light to dark brown, with characteristic dark brown violin marking on back
Legs | 8
Shape | Round
Size | 5/8"
Antennae | No
Flying | No

Brown recluse spiders are nocturnal and eat other bugs like cockroaches and crickets. Male brown recluse spiders wander farther than females and will crawl into shoes or other clothing.

Brown recluse spiders often live outdoors in debris and wood piles. They can be found indoors in storage areas and dark recesses.

Like the black widow spider, the brown recluse spider bites in defense and does not bite humans instinctively. They will bite humans when the clothing they are hiding in is worn. The brown recluse spider bite is painful and can produce an open, ulcerating sore.

To avoid brown recluse spiders, avoid keeping clothing on the floor. Store clothing and shoes inside plastic containers, and shake out all clothing that has been in a hamper before wearing or washing.

*Information from the National Pest Management Association

House Spider / Hobo Spider

The house spider is brown and its body is approximately three-eighths of an inch long. The hobo spider is a funnel web spider. This species is known to be aggressive, but avoids human contact.

Hobo spider

House/Hobo Spider Facts

This spider’s body is spherical and white to brown in colour. They have dark markings. Male legs are orange and female legs are yellow.

Habits & Habitat
House spiders are found all over the world in corners, crawlspaces, basements, under furniture and near windows. The hobo spider is specific to western Canada.

The venom of these spiders is necrotic, meaning their bites cause open wounds. These wounds are slow to heal. Luckily, bites from these spiders are rare.

The control of these spiders is hard unless you directly spray the spiders with pest control chemicals. The best method to rid yourself of these spiders is good housekeeping. Sorptive dusts, supplied by your pest control experts, can provide permanent solutions against spiders because they can be used in favourite hiding spaces for these spiders.

*Information from the National Pest Management Association

wolf spider

Wolf spiders can range in size from 1 to 30 mm. Their colouration usually blends well with the colouration of their habitat.

Wolf Spider

Wolf Spider Facts
In contrast to spiders that hunt with webs, these spiders hunt down their prey. They can appear as tarantulas, with dark colouration and bristles on the legs and body. Wolf spiders have very good eyesight. The distinguishing feature of these spiders is that the females carry the egg sacs with them. When the spiderlings hatch, the female opens the egg sac and then they attach themselves to the female’s abdomen until their first molt.

Habits & Habitat
Wolf spiders are found on the ground in almost any habitat, as long as there is earth in which to burrow. They prefer to nest near places where prey are readily available, such as near doors, windows, and plants, and in basements and garages.

Wolf spiders are not naturally aggressive. Wolf spider bites are venomous. Bites cause pain, swelling and itchiness. The wound may take a few days to heal and have a swollen character.

To prevent nesting of wolf spiders, seal any cracks or openings on the outside of your house. Use weather stripping on doors and windows and repair damage to them. Look for cracks in your basement or attic windows and pipes, repairing them as needed. We recommend you remove vegetation on the outer walls of your house. Use proper storage containers and keep outdoor piles away from the house. Try to keep your porch, crawl space, basement and attic dry. Controlling other pests will, in turn, deprive food from the wolf spider, reducing a problem infestation of these spiders.

*Information from the National Pest Management Association


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