Dave In my experiences with pitfall traps, I don't recall capturing many earthworms. I have captured occasional snails, slugs, and some larvae, more likely to capture insect nymphs. If you do use pitfall traps, I have always used propylene glycol as the killing agent/preservative, 2-4 cm deep, since it isn't too attractive to insects or mammals. This is the main ingredient in low toxicity antifreeze and most boat/RV antifreeze. The labels are pretty clear regarding the ingredients. I wouldn't use ethylene glycol, main ingredient in most other antifreeze. This is attractive to insects and mammals. Since pitfall traps are usually passive, an attractant isn't usually wanted. Even using propylene glycol, you will capture some mammals in pitfall traps; shrews and voles are the most common in my experience. Checking traps every week or 2 weeks is acceptable, I have done both for different studies.
For sampling earthworms, I would think soil cores (10-15 x 25 cm?) or small soil pits (25 x 25 x 25 cm?) would be the most effective technique. Sieve the soil and remove the earthworms. Jordan -- Jordan M. Marshall, Ph.D. School of Forest Resources and Environmental Science Michigan Technological University Cooperative Emerald Ash Borer Project 5936 Ford Ct. Suite 200 Brighton, MI 48116 Ph (810) 844-2701 Fax (810) 844-0583 www.jordanmarshall.com > "David H. Byman" <[EMAIL PROTECTED]> > Sent by: "Ecological Society of America: grants, jobs, news" > <ECOLOG-L@LISTSERV.UMD.EDU> > 05/23/2008 10:54 PM > Please respond to > "David H. Byman" <[EMAIL PROTECTED]> > > > To > ECOLOG-L@LISTSERV.UMD.EDU > cc > > Subject > [ECOLOG-L] Catching soil invertebrates > > > > > > > Dear All: I would like to do a comparative study of soil > macroinvertebrates inside and outside a deer exclosure. As I am > interested in evaluating the available of shrew food as affected by heavy > deer browsing, I would like to census the populations of snails, slugs, > earthworms and insect larvae inside and outside the exclosure fence. > Are pitfall traps the best technique for all these invertebrate > groups? If pitfalls are a good technique, should I put a layer of > glycerol or some other preservative to preserve the animals in the bottom > of the can in case I can't visit the traps more than once a week? Thanks > for your help. > Dave Byman > > > > David Byman > Asst. Prof. Biology > Penn State University > Worthington Scranton Campus > 120 Ridge View Drive > Dunmore PA 18512-1699 > 570-963-2586 > mailto:[EMAIL PROTECTED] >
