Setting Traps on the Forest Floor

Friday, July 9, 2010
Caroline Chaboo

Today is a big day: reviewing the available established plant plots in the area, relocating their markers (boundaries of edges and internal sub-quadrats), selecting a plot we will follow in the next few years, and setting up several kinds of traps to capture insects.  One of the reasons arthropods are so diverse is because they divide any habitat into 1000s of microhabitats, with many insects specializing on particular aspects — flower feeders, seed drillers, stem and leaf miners, soil arthropods, root feeders, parasites, parasitoids, predators….an insect specialist must have an array of tools if they want to sample that ecological diversity.

Selecting the first one-half plot was a piece of cake but locating the internal markers was not so easy.  There had been several fallen trees in recent years, and these gaps in the canopy create particular kinds of habitat for sun-loving plants and their arthropod associates.  Walking around on foot is not so easy.  We kept losing sight of each other, even though I was using florescent orange tape to mark our path.

After a sweaty but productive few hours, we had laid down malaise traps, flight intercept traps, colorful pan traps, and pitfall traps.  Each one would sub-sample a slightly different group of forest arthropods.  As all these traps were on the forest floor, we would not be sampling the canopy fauna so well this time but next year we will have canopy foggers and other canopy traps.

For some insects, you have to look for them during their most active part of the day. Arthropods may be most active during the day, at dawn and dusk (crepuscular) or at nights. So night walks are necessary for some species.

—Caroline