While almost all aspects of having an outdoor wedding are pleasant, being attacked by annoying insects is not - for you or your guests! Take the following precautions to make sure everyone comes away unbitten.
Timing - There are certain times of day that are more "buggy" than others - particularly at dusk. Try to schedule your day around it if it's impossible to avoid all insect - laden times of day. You don't want your guests (or you!) to be slapping off mosquitoes while you say "I do." And since it's likely that at your reception, guests will be dancing-the-night-away (and with the help of a little champagne) they won't notice the swarming bugs as much.
Citronella - Stock up on torches and candles containing citronella. Citronella is a natural oil that deters insects and is widely available. Place the torches and candles around your reception area to ward off flying pests. This will help keep bug number down inside your tent.
Repellent - If you're worried that insects will be a particularly pesty problem at your wedding, equip your guests with a travel sized bottle of bug repellent. You can hand them out at your ceremony or include them in your out-of-town guest welcome baskets. Other insect repellent products on the market include: small packets of repellent wipes as well as patches. Do your homework and find out what will work best for you.
For the Kids - Many mainstream bug repellents are not safe for children to use. If there will be children at your wedding, make sure to purchase kid-friendly bug repellent for your littlest guests. Their parents will be very grateful.
Cover Up - In addition to bug repellents; encourage your guests to wear and/or bring along clothing to cover bare skin if possible. They'll come away with fewer bug bites and have a much happier time at your celebration.
Natural Alternatives - If chemically-based insect repellents aren't your thing, there are many natural oils that discourage those little buggers from attacking; like Eucalyptus and Lemongrass.
There you have it! Easy precautions that your guests will very much appreciate. Enjoy your wedding without the buzz from the mosquitoes, but instead from a cocktail or two!