Spider identification
The big fat spider in the big wheel web across the doorway in September, the one that makes people step back, is usually the cross orb weaver. It has been there all summer, growing, and it is one of the most photographed spiders in Ontario for good reason.
Fat bodied, 1 to 2 cm, brown, orange or sometimes grey, with a row of white dots forming a cross on the top of the abdomen. Legs are banded and spiny. The web is a large, neat orb, often 30 cm or more across, strung between a porch post and the eaves, across a doorway or over a window. Unlike most orb weavers it sits head down in the hub of the web by day, which makes it easy to see and identify.
Anywhere with two anchor points and insect traffic: porch posts, railings, door and window frames, between shrubs and the wall, on fences and in the garden. A European species now common across southern Ontario.
Small and unnoticed in spring and early summer, large and obvious from August to the first hard frost in October. The female lays one egg sac in a sheltered spot in fall and dies; the spiderlings emerge the following May.
Only if squeezed against skin, and then mild and local. It is not aggressive and will drop from the web if disturbed. Most "spider bites" in Ontario are never confirmed; see the bite section of our guide to common spiders in Ontario for what a real one looks like.
Removal takes the web, the spider and the egg sac. Because this species keeps to one site, rebuilding its web in the same frame, a single pass clears it and it does not come back the way the lakeside species do. We rarely need to treat for it. If the web is in the garden or on a fence rather than the house we leave it; it is doing useful work and the frost ends it anyway. Every visit ends with a written summary of what we found and where product was applied, if any. Our spider control service and 60 day guarantee pages have the details and pricing.
Barn orb weaver, Spotted orb weaver, Marbled orb weaver. The barn and spotted orb weavers are the same size and build similar webs but are plain hairy brown without the white cross and hide by day. The marbled orb weaver is pumpkin orange and found in shrubs and tall grass in October. The full list with photos is in the common spiders in Ontario guide.
Good to know
No. It is one of the least concerning spiders in Ontario despite its size. Its bite is rare and mild.
On the house, around doorways and lights, we remove it with the web and the egg sac. In the garden or on a fence it is harmless and useful and we would leave it.
It has been growing since May. By September the female is full size and carrying eggs, which is when people notice the web.
Related guides: When is spider season along Lake Huron, The spider life cycle and why timing matters. Service areas where this spider is found: Goderich, Bayfield, Sarnia and Bright's Grove.
