A pitfall trap is an essential tool for catching and studying ground-dwelling insects, particularly springtails and ground beetles. You can build and set up a simple pitfall trap in less than half an hour, using recycled materials.
Assemble your materials – a trowel, a clean coffee can with a plastic lid, four rocks or similar objects of equal size, and a board or piece of slate 4-6 inches wider than the coffee can.
Dig a hole the size of the coffee can. The depth of the hole should be the height of the coffee can, and the can should fit snugly without gaps around the outside.
Place the coffee can in the hole so the top is flush with the surface of the soil. If it doesn’t fit correctly, you will need to remove or add soil to the hole until it does.
Put the four rocks or other objects on the soil surface an inch or two from the edge of the coffee can. The rocks should be spaced apart from each other to make “legs” for the board that will cover the pitfall trap.
Put the board or piece of slate on top of the four rocks to protect the pitfall trap from rain and debris. It will also create a cool, shady area that will attract ground insects seeking moisture and shade.
- Close the coffee can with the plastic lid when you cannot attend to your pitfall trap, or if heavy rain is expected.
- Make sure to check the trap at least once every 24 hours, and remove any insects you have caught. Keep them for study or release them.
- If you want specimens for a collection and don’t need the insects to be alive, pour one inch of water in the pitfall trap and add 1-2 drops of dish soap.
What You Need
- coffee can with a plastic lid
- four rocks or objects of equal size
- a board or piece of slight large wider than the coffee can
- a trowel