I have a can of bug spray. The label is in another language which I can not even type in order to do an online translation, but the ingredients are in romanized writing:
Metofluthrin 0.012% w/w
Phenothrin 0.100%
Cyphenothrin 0.100%
Wikipedia: Metofluthrin, Phenothrin, Cyphenothrin
I've been seeing small (3~4mm) dark flying bugs that seem to be able to take a direct hit. They may be grounded, but after a minute or two walking around and cleaning their wings, they fly away.
The spray worked very effectively on the cockroach I bought it for; this kind of thing happened about 90 seconds after a direct hit. Here they don't really infest as much as just wander in off the street and can't find their way out again.
I assume if I get rid of any residual sources of food or water the little flying things should die off. But I was really shocked to see them fly away undaunted after some serious aerosol action.
Here are some snapshots I took of the small bug trying to eat my spicy noodles. It's actually not so dark. Please please tell me it's not a tiny baby cockroach!