Pitfall Traps

To measure the influence of plant community on the diversity of ground arthropods. This is a study students can conduct on their soil sample. Comparing data can be a yearlong study.

Small yogurt container
Large yogurt container
Shallow cone (cardboard covered by aluminum)
Lid with 4 supports
Hand trowels

Teacher Procedure:

1. Have students construct pitfall trap according to design. See below. (also available for purchase in science catalogs).
2. In outdoor area, have students select their own plot of land to study. Select a variety of soil types with varying vegetations so data can be compared.
3. Using hand trowels students dig a hole large enough to fit a large yogurt container with its top level with the ground.
4. Fit trap into ground; cover the top with a lid that acts only to protect against other particles from dropping into pit. It should not prevent arthropods from crawling up to edge of container.
5. After 24 hours remove small yogurt container and strain insects. Replace small container and antifreeze.

Other research questions:

1. How does the plant community affect the diversity and number of ground arthropods?
2. How do ground arthropod numbers change in response to the seasons.
3. How do different soil types affect the numbers and diversity of ground arthropods?

Next page Pitfall Trap:


1. Traps should be set so there is no space between cone and large container and ground.
2. Lid should be supported by 4 legs in such a way that insects can crawl under lid. Top of lid should be camouflaged.
3. When sampling the trap, remove the small yogurt container. Strain insects from fluid and replace antifreeze. Small container can be put back inside trap for more collections.

Adapted from Bob Madar

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