During the winter between field seasons I sort through invertebrate samples in the lab. Here is a photo of what one sample looks like. This sample contains invertebrates that I collected from pitfall traps in a native grassland site (a site with relatively little invasive plant species) at TNC Boardman Preserve, OR. I sort through the sample taking out all of the insects and freeze them in case I want to use them later. Then I preserve all of the spiders and arachnids (wind scorpions) in ethanol. I will eventually identify each of the spiders to genus. In this photo it is easy to see all of the different beetles that I collect in the traps.
Here is an example of what a pitfall trap looks like. It's a plastic cup that is placed in a hole with the lip flush to the surface. Invertebrates crawl across the soil and fall into the trap. You can fill the trap with a mixture of soap and water or propylene glycol (RV or marine antifreeze -- it's safe for wildlife and the environment). This trap is filled with propylene glycol because in eastern Oregon heat evaporates the water too quickly! I leave these traps out for one week and then pick them up and collect the invertebrates.
Lauren Smith is currently a PhD student at Oregon State University researching the effect of grassland restoration on native bee and spider communities. Visit her website here.