Ontario is home to thousands of species of unique spiders and this article only lists a handful of the most common, native species.
Morphologically, these spiders vary greatly in terms of color, shape, patterns, leg length, and abdomen size.
Arachnids have a bad reputation, and although some species are dangerous to humans, this is a minute number in comparison to the abundance of species that exist. Spiders tend to avoid humans and even benefit us by eating pesky insects.
Most Venomous Spiders in Ontario
1. Black Widow Spider
Credit: Judy Gallagher
Scientific Name: Latrodectus variolus
Black widows are almost entirely glossy black, aside from the characteristic red hourglass shape that adorns their bulbous abdomen.
Where Will They Be Hiding?
The black widow resides in dark and woody areas. Common places they can be found include log piles, low-lying vegetation, and in cracks and crevices. They may venture into houses, making their webs in clothes piles, shoes, or under furniture.
Are They Dangerous?
The venom a black widow possesses is 15 times stronger than that of a rattlesnake. A bite from a black widow can cause muscle fatigue, vomiting, and paralysis of the diaphragm in humans. In young children, vulnerable individuals, and the elderly, a black widow bite could potentially be fatal.
Female black widows are larger and more dangerous than their male counterparts.
Despite their reputation, these spiders bite out of self-defense. Per year, around 4 to 8 people will die from a black widow bite.
Common Spiders in Ontario Identification
2. Wolf Spider
Credit: Muhammad Mahdi Karim
Scientific Name: Lycosidae spp.
Wolf spiders are a mixture of tan and brown shades, creating a mottled appearance that helps them to camouflage with their surroundings. .
Wolf spiders get their name from their hunting strategy. Rather than spinning webs to catch insects, they pounce on their prey in a wolf-like manner.
Where Will They Be Hiding?
Wolf spiders are a ground-dwelling species and can be found hiding under rocks, logs, plants, and leaf litter. They may venture into homes where they are likely to hide among houseplants, in dark corners, and under furniture.
Are They Dangerous?
Generally speaking, wolf spiders are not aggressive toward humans unless provoked. As they are a fairly large species of spider, a bite from them may be painful, but their venom is not poisonous to humans.
3. Cellar Spider
Credit: Ryan Hodnett
Scientific Name: Pholcus phalangioides
Cellar spiders are a mixture of brown shades and generally have a darker abdomen and paler legs. They are also called ‘daddy long-leg spiders’ due to their thin and spindly legs, that can reach up to 2 inches in length.
Where Will They Be Hiding?
Cellar spiders favor warm and stable temperatures, meaning they are almost always found indoors. These spiders spin loose and messy webs in the corners of rooms or under furniture.
Are They Dangerous?
Cellar spiders pose no threat to humans. Although they possess venom, it is not harmful to humans and their jaws are not strong enough to pierce through human flesh.
4. Black-Footed Yellow Sac Spider
Credit: Vengolis
Scientific Name: Cheiracanthium inclusum
So-called due to its yellow-beige coloring and black tips on the end of its legs. They often have an orange strip running down the center of their abdomen.
Where Will They Be Hiding?
Black-footed yellow sac spiders are commonly found among foliage in forests, wooded areas, and gardens. However, they may venture into human homes to shelter from cold weather.
Are They Dangerous?
Attacks only occur when provoked, which is often when they become entangled in clothing. They are venomous, but it is not strong enough to cause death in humans. The site may lead to localized swelling but not necrosis as many people believe.
5. Dark Fishing Spider
Credit: Ryan Hodnett
Scientific Name: Dolomedes tenebrosus
Dark fishing spiders are pale to dark brown. Their legs are stripy while their abdomen is adorned with M-shaped patterns. They are the largest, native spider species to Ontario, with females reaching 26mm in length.
Where Will They Be Hiding?
As their name suggests, these spiders inhabit wooded areas near water sources, since they prey on aquatic organisms. They can also be found dwelling on trees. They may venture into houses over winter.
Are They Dangerous?
Like many spider species, they actively avoid humans. Although they can bite and deliver venom, it is not dangerous to humans. It is similar in severity to a wasp sting.
6. European Garden Spider
Credit: Muséum de Toulouse
Scientific Name: Araneus diadematus
Generally, they are yellow-brown in color although some can appear grayer. They have mottled white markings on their abdomen, which create a cross-like shape. They are thickly-haired.
The European garden spider is also called the diadem spider, orange cross spider, crowned orb weaver, and pumpkin spider.
Where Will They Be Hiding?
As their name suggests, these spiders are common in gardens and also meadows, woodland clearings, and hedgerows. They tend to avoid houses and prefer to live outside.
Are They Dangerous?
They are not aggressive and seldom bite people. Although they carry venom, it is not dangerous to humans.
7. Bold Jumping Spider
Credit: Kaldari
Scientific Name: Phidippus auxdax
Bold jumping spiders are glossy black and have a pattern of spots on their abdomen. These spots tend to be orange in juveniles and white in adults.
Their mouthparts are bright green-blue. They have forward-facing eyes, proving them with excellent depth perception.
Where Will They Be Hiding?
Bold jumping spiders frequent open habitats such as fields and grasslands. This is because they do not build webs to catch their prey, but instead chase and pounce on their prey.
Flat and vertical habitats are favored by this species, meaning they may be common in gardens. Occasionally they may enter houses where they can be found on windowsill corners.
Are They Dangerous?
Like many spider species, they seldom bite humans. Their venom is not harmful to humans. Symptoms of a bite are mild and may include itching and redness.
8. Zebra Spider
Credit: Kaldari
Scientific Name: Salticus scenicus
As their name suggests, the pattern and coloration of these spiders somewhat resemble a zebra, as they are black and white striped. They are a species of jumping spiders.
Where Will They Be Hiding?
Due to their hunting strategy of stalking and pouncing, these spiders prefer open and flat habitats, as they provide effective hunting grounds. They frequent vertical habitats, meaning they are often found on garden fences and on the walls of buildings.
Are They Dangerous?
Zebra spiders are not aggressive and are not known for biting people. Their venom is not dangerous to humans. If bitten, only mild irritation will occur.
9. Black and Yellow Garden Spider
Credit: Dakota L.
Scientific Name: Argiope aurantia
The black and yellow garden spider also goes by the names the zigzag spider, corn spider, golden garden spider, and steeler spider.
The large abdomen is patterned with bold black and yellow markings. Their pointed legs are striped with black and red.
Where Will They Be Hiding?
Black and yellow garden spiders are mainly found in gardens. They live in open areas with light vegetation in which they can build their webs. Durning colder months, they may venture into outbuildings or along the eaves of houses.
Are They Dangerous?
Like many spiders, this species uses its venom to immobilize its prey. However, their venom is not dangerous to humans. They avoid biting people, but if they do it feels similar to a bee sting.
10. Furrow Spider
Credit: Quartl
Scientific Name: Lariniodes cornutus
Furrow spiders are also called orb spiders or foliate spiders. They have large, bulbous abdomens. Their legs are red-brown with black stripes. Their abdomen varies greatly in color, including black, white, gray, and red, and is adorned with an arrow-like pattern.
Where Will They Be Hiding?
Furrow spiders are most commonly found in damp, moist areas in close proximity to water. They weave their webs close to the ground. They are often found in gardens and along the eaves and windows of houses.
Are They Dangerous?
Furrow spiders are not a threat to humans. They may only bite if highly provoked, but their venom is not dangerous to humans. The bite itself may cause mild discomfort.
11. Hobo Spider
Credit: Rainer Altenkamp
Scientific Name: Eratigena agrestis
Hobo spiders occur in a variety of brown shades. Their legs are quite long and skinny and they have chevron patterns running down their abdomen.
Where Will They Be Hiding?
They favor warm and dry habitats and will inhabit suitable crevices. They avoid human habituations.
Are They Dangerous?
Many people believe hobo spiders are dangerous because their bites cause necrosis. However, their venom does not cause damage to humans and they seldom bite people.
Other Spiders Native to Ontario
Here’s a list of other common spiders native to Ontario
- Trapdoor Spider (Ctenizidae spp.)
- Running Crab Spider (Philodromus margaritatus)
- Banana Spider (Nephila clavipes)
- American Grass Spider (Angelenopis potteri)
- Red Spotted Ant Mimic Spider (Castianeira descripta)
- Spitting Spider (Scytodes thoracicia)
- Bowl and Doily Spider (Frontinella communis)
- Giant House Spider (Eratigena atrica)
House Spider (Achaearanea tepidariorum)