DESIGN FOR A LOW-COST, COVERED, RAMP PITFALL TRAP

Extract

Pitfall traps are used extensively to sample ground-dwelling arthropods for systematic and ecological studies. They are inexpensive and easy to use and can be operated for relatively long periods of time without maintenance. These traps can collect arthropods in numbers that are suitable for rigorous statistical analysis, although their efficiency is influenced by many biotic and abiotic variables (Greenslade 1964; Spence and Niemelä 1994). Typically, pitfall traps are most productive when they are buried in the substrate, with the upper edge flush with the soil surface; traps with their upper edge above the substrate are much less effective (Greenslade 1964). Because of this, studies of ground-dwelling arthropods in habitats where soil is thin or lacking, or where digging is difficult, are left with no satisfactory alternatives to pitfall traps. A ramp pitfall trap developed by Bostanian et al. (1983) is useful in these habitats because it can be placed on the ground surface without digging. However, the original metal design was strongly biased toward the collection of large (>10 mm) ground beetles (Coleoptera: Carabidae) (Bostanian et al. 1983); it was also large, bulky, and relatively expensive. In this paper, we describe a ramp pitfall trap that is inexpensive, easily constructed, and durable. The trap is light, portable, easily installed, and effective in collecting all sizes of arthropods and can be used in many habitat types.