Many may already know this:
To keep the bugs down, and away...ESPECIALLY MOSQUITOS...we have a little fan that stays outside. I believe I heard that mosquitos cannot/have a hard time flying in 5 or 10 mile/hr wind....we tested that theory and it works!
Throw a bar of Zest soap (take it out of the box) in a little nook/cranny/corner or wherever to keep a fresh scent going while you have your r.v. closed up. I got overly excited and threw two bars out in our little Bambi. That theory worked as well!
Disclaimer: The above are not my home grown ideas, I happened to catch a few episodes of R.V. Today (?) or whatever that show is on satellite.
OK: tip three, same show...
put some coffee grounds in a little tupperware container and put in your fridge and/or freezer while r.v. not in use. something about helps to reduce moisture and provides a better smell than the ole' storage smell. and...guess what...this works too!