Essential oils would be your best bet. Here are some of the best insect repellants: citronella, (sweet) bay, cedarwood, cinammon, clove, eucalyptus, fennel, geranium, lavender, peppermint, rosemary and thyme. I would recommend adding the following to a carrier oil such as olive, coconut, sweet almond, or jojoba. Peace and prosperity.
I've heard about the banana thing as well. I actually cut back on bananas because of it. I heard eating lots of garlic and lemon juice helps. I also rub citronella essential oil on me which was much more effective then other natural repellents I've tried.
Cedar oil works great to repel insects! My herbalist would say that if you clean out your body from the inside out by detoxing w/ raw foods & such the mosquitoes will not be a problem. He also advised eating lots of garlic to keep them away...! ;)