Yep, I am told by my wife and friends that they do bite. However, even though they light on me every time I go on the porch, I've never been bitten. I just must not taste good, or they don't like tough meat. Anyway, if they are somewhere that you don't mind getting wet, soapy water will kill them.
After the first freeze, next time it get's warm at all as you are finding, the asian beetles will swarm your house. Be ready to spray and spray the whole house out side from peak of the roof to the foundation. Kill 'em all while they are still outside.
The permethrin will dry on the outside and actively kill bugs for several weeks so long as it gets a chance to dry.
That bottle there for about $30 something would spray my own entire house, detached garage, and another garage and fill up my pump up fruit sprayer twice a year, for about 4 - 5 years.
Use it in the fall for the lady bugs. Use it in the spring when the wood boring bees show up. Use it all summer long to spray down your pants and shoes to keep ticks off you.
We have had some real cold weather and I have not seen any for a week so hope the infestation will not return last year was very bad.
If you do not kill them, they will come back to the same places every year, over and over and bring back all their off spring with them. Kill them all for a few years and it will get less and less. Ignore them and they will get worse and worse every year.
They just mysteriously show up here about 5 yrs. ago .I first thought they were our common lady bugs they look identical but you can smell the difference if you mash one . They don't seem to hurt anything . Just make a big mess in my utility building . I think Asia is where they immigrated from . No doubt on a caravan .
The were deliberately imported here by the farmers and the US ag department to battle aphid on soybeans. Of course it was promised they would "never be able to reproduce HERE".