# Brown Recluse Spider in Ontario — Spider Squad

## The Short Answer
Brown recluse spiders (Loxosceles reclusa) are **not established in Ontario**. They are not native to Canada and do not have wild-reproducing populations in Ontario.

## Where Brown Recluse Actually Live
The brown recluse's established range in North America is predominantly:
- The south-central United States (Missouri, Arkansas, Oklahoma, Kansas, Texas, Tennessee, and surrounding states)
- Parts of the midwest United States

Their range does not naturally extend into Canada. The species requires specific temperature and humidity conditions to establish and reproduce.

## Why This Comes Up
Three reasons brown recluse is frequently reported in Ontario despite not being established here:

**1. Misidentification of other spiders.** Wolf spiders, ground spiders, and certain house spiders are brown, ground-dwelling, and look superficially similar to brown recluse in photographs. Most Ontario "brown recluse" reports turn out to be wolf spiders or other common species.

**2. Wound misattribution.** Necrotic wounds (tissue-destroying lesions) from bacterial infections, other spider bites, or other causes are frequently attributed to brown recluse without evidence. This has been documented extensively in medical literature. Dermatologists in non-recluse states routinely receive patients diagnosed with "brown recluse bites" by physicians who have never seen the spider.

**3. Occasional hitchhiker specimens.** Brown recluse can arrive in Ontario in shipments of goods from the US (particularly from the south-central states). These are isolated individuals — not establishing populations. A single specimen found in a box from a US shipment is not evidence of local population.

## How to Identify a Brown Recluse
If you genuinely believe you've found one, key features are:
- Six eyes arranged in three pairs of two (most spiders have eight eyes)
- A dark violin or fiddle-shaped marking on the cephalothorax (the front body section) — this is where the name "fiddle-back spider" comes from
- Uniform brown colour without strong leg banding or markings
- Body: 6 to 11 mm

The eye arrangement is the most reliable feature. Most spiders have eight eyes in two rows of four.

## What to Do
If you've found a spider you can't identify that concerns you, contact Spider Squad or submit a photo to Entomology at a Canadian university or museum for confirmation. The probability that an unidentified brown spider in an Ontario home is a brown recluse is very low.

For a suspected bite with expanding redness, warmth, or tissue involvement, see a physician — but be aware that necrotic wounds in Ontario are far more likely to be caused by bacterial infections (MRSA is a common culprit for necrotic lesions) than spider bites.