Image hide at certain size

Is there a way to make an image hide or disappear at a certain screen size? I have a map on my site and at desktop width it is great, but when I view on mobile it is not looking good. I know I can have the image resize but that will not work in this instance because I have hotspots on the map.
Is there a media query I can do or another css hack to hide the image or hide the div at a certain screen size?

Or what is the hack or css I can do to make sure the div floats below my sidebar instead of sliding over my sidebar?

P.S. it is a responsive wordpress theme that I am using

Thanks!