Make Mosquitoes Bug Off
Try taking garlic capsules or brewers yeast - apparently the little critters can be warded off by the smell.
If you do get bitten, calendula or tea tree oil can help soothe the itch and reduce swelling. These herbs also have an antiseptic quality and some say they act as a repellent.
For bee stings and other insect bites, a tincture of echinacea and goldenseal may be effective. Vitamin C helps reduce histamine release, resulting in a milder reaction. Quercetin (a flavenoid) and bromelian (an enzyme derived from pineapple) have an anti-inflammatory effect which can help ease the symptoms of bites and stings.