Hillock , 11 months ago

I am going to assume you have a cellar spider. Removing part of the web isn't going to directly harm them. They don't recycle their web so you aren't even removing nutrients from them.

The only way it's going to affect them is by reducing their chances of catching prey. Cellar spiders don't have a sticky web and rather rely on prey brushing up against their web, then rushing there and killing it with a bite. So you are reducing the area they are covering.

They also usually just gradually increase the size of their web. So it's unlikely it will try to rebuild everything you removed at once. Meaning it's not going to waste too much energy.