If wasps are appearing in your yard with greater regularity, you may be in need of a wasp trap. While wasps can be beneficial to gardens preying on other insects, they can be aggressive and their stings are painful and can cause an allergic reaction in some people. However, if you can't find the nest or it's actually in a neighbor's garden, you can use a wasp trap to lure them away from busy areas, trap them and kill them. Rather than using pesticides it is possible to make an efficient wasp trap using natural materials.
Homemade traps have the advantage of being very cheap and they use items that you may already have in the house such as empty soda bottles. They can be adapted for use on the ground or hanging from a tree or fence depending on your requirements. For safety reasons it is advisable to use a trap hung at around 4 feet from the ground so that it will not be stepped on by accident.
To make a simple homemade trap take an empty 2 or 3 liter soda bottle and cut off the top section (an inch or so under the shoulder of the bottle). Remove and discard the bottle cap then smear the neck of the bottle with cooking oil so that the trapped wasps will not be able to get any traction on it. Make a couple of holes in the plastic and thread some string through to hang the trap up. Add your bait and some water with a little detergent in it to the bottom section of the bottle. The level of the water should be significantly lower than where the bottle neck reaches so that the wasps have to fully enter the trap to get the bait. A variety of items may be used as bait—meat, mashed grapes, jam, sugar to name only a few. One you have added the bait place the inverted top section inside the bottom and tape it together. You must empty the trap daily because as more and more wasps get caught they can form a raft on the water that saves other wasps from drowning and can provide a means of escape.
If you don't want to make your own wasp trap there are numerous poison-free varieties available in shops and online. Generally, these consist of a reusable container that you place the bait or lure inside. Some use sticky cards rather than water to keep the wasps trapped, however, they must still be checked regularly to minimize the number of wasps that manage to escape.
Always place a wasp trap at least 20 feet from a picnic or play area. Setting a wasp trap in early spring or late winter can be an advantage as more queens are around at that time. If you trap and kill a queen the other wasps will go somewhere else to make their nest.
Be very careful when emptying any type of wasp trap. Any living wasps that escape may return with other members of the colony in an aggressive swarm. The same thing can happen if you crush the bodies. Make sure any wasps that you catch are dead by filling the trap with hot soapy water or placing it in a plastic bag and putting it in the freezer for a few days. Bury the dead wasps in the garden or flush them down the toilet.