is there any way to get rid of or kill the box elder and the Asian bugs?

Answer 1

From bugspray.com:

"If you have seen them congregating on a tree or the side of your house, you need to spray them immediately. Use CYPERMETHRIN and SPREADER STICKER for a quick kill. Mix these in a SPRAYER and treat any tree, plant or structure you see them accumulating on. This treatment will reduce the active ones wanting to nest in and around your home. By reducing these numbers, you are reducing the amount that could find their way inside. If you are treating an infestation which is outside only, the Cypermethrin will kill off those which are emerging. However, for long term control, the treatment must reach down to where the boxelders are nesting. This could be under a pile of thick mulch or further down in the soil and to the roots of the host plant. For such situations, the use of DELTAGUARD GRANULES will probably work better than just liquid alone. Apply the Granules with a GRANULE SPREADER to insure you get a good even distribution. In most cases, it is better to treat and kill off
the established population instead of removing the infested plant. Simply removing the infested plant will rarely remove all the Boxelders and in most cases they will just move over to the next
available host. Prevent this from happening if you have a lot of plants infested by first applying some of the Granules and then spraying over the top with the Cypermethrin."

Also, from Pest Control Canada:

"We live in Niagara Region and were swamped with the Box Elder bugs and it took me quite some time to track down what they were. (Didn't find your site at the time I was looking) Someone suggested dish soap and hot water sprayed on them to kill them and boy, did that ever work! It was suggested that I use "Dawn" brand concentrate dish liquid, and I did, but when I ran out I just used Sunlight and that did the trick, also. It killed them (perhaps by suffocation?) and sure made the outside of the house smell nice. I don't know if you want to suggest this treatment to others, but we found it worked for us.
Sincerely, Diane, St. Catharines, ON"

Hope you find something here that works for you!

Answer 2

It always works for me when I step on them.