An Exception to the Exception?

I have a  policy of not harming spiders, even when they build webs in the house, because of the good they do, provided the webs are kept out of sight, i.e., down by the floor under the cabinet overhangs, behind immovable objects such as sofas, etc.

Overnight, someone broke the rule and this morning I found a small web with small occupant strung in my bathroom between the sink faucet and the mirror behind it. I was about to remove it when I noticed the corpse of a mosquito lying beneath it. It was one of those small, silent mosquitoes we have down here that are very difficult to see and give no warning, going for knuckles and other joints and raising extremely painful (and long lasting) welts.

So now I'm torn.