I've always just used disposable plastic drinking cups for ptifall traps. They are inexpensive, light-weight to carry in the field, and easy to replace if damaged. I usually use 2 cups per trap, this way the outer one stays in the ground and the inner one can be removed to empty/check. If you're doing multiple checks throughout the season, it minimizes soil and litter disturbance once they are set.
Lids are a tough thing because you want the insects to crawl in unhindered but limit small mammal captures. I typically use a styrofoam plate and some long nails to support the plate. In places where I've had lots of raccoon activity (they like pulling traps out), I've used a square of chicken wire over the trap held in place with lawn stakes. It helped, but I don't know how that impacted insect captures. How often are you going to check the traps? I'd recommend propylene glycol for the wet component. I've used the low-tox antifreeze, but marine/RV antifreeze is cheaper (it does contain water, but I haven't had much issue with it). Ethylene glycol will attract mammals and will likely shift your traps from passive to active for insects. Even after a week or two, the insects should still be preserved well enough to ID in propylene glycol. Marshall plantecologylab.com -----Original Message----- Date: Wed, 6 May 2015 16:14:14 -0600 From: Sammantha Rowland <sammantha.rowl...@western.edu> Subject: Entomological Wet Pitfall Traps Hey all - I'm conducting a study of diversity and abundance of insects in a sage-steppe habitat in relation to riparian zones, and I need to install wet pitfall traps for 60+ days. After exploring options on BioQuip, I've noticed that most pitfall traps are cheaply made. The Colorado Parks and Wildlife and the USFWS require that I put a lid on the wet trap to keep animals out. I am debating on what would be the best way to either construct or purchase these traps, and whether I should use formaldehyde (10%) or ethylene glycol in the traps. Does anyone out there have experience that they would like to share or any suggestions for how to construct an animal-proof wet pitfall trap? -- Samm Rowland Masters in Environmental Management Integrated Land Management Western Colorado State University 917.763.1271 sammantha.rowl...@western.edu
