Why won't this spray kill this bug (household insecticide); could it be so selective?
It's a tiny baby cockroach.  Sorry.


http://animalia-life.club/other/german-cockroach-nymph.html

I looked up your chemicals; the first (metofluthrin) is mosquito repellant and the others are for fleas and mosquitoes.  The combo makes me think that this is something intended for spraying on the body or on animals.  It is not strong enough. 

You need to get a bigger boat.  Get a spray made for roaches.