Monitoring the Cheese Snail, Helicodonta obvoluta

John Glasgow

During the afternoon of 26th July 2011 I made another visit to West Wood , a Forestry Commission managed woodland to the west of Winchester to see how this species was faring. After a period of variable weather with some prolonged dry spells there was substantial rainfall very early that morning which hadn’t penetrated the beech canopy as much as I might have expected.


Searching in the same compartment previously visited (see Mollusc World, Issue 22, March 2010 and Issue 25, March 2011), no mollusc activity was observed on the tree trunks. The immediate top surface of the leaf litter was fairly dry with reasonable dampness to c. 10 cms deep. Harder work was required! This was rolling fallen logs from c. 10 to 30 cm diameter.


One hour and forty minutes of this returned a satisfying 40 live H. obvoluta  including some juveniles and one with a well-sealed epiphragm. Other species recorded were:

Pomatia elegans, Oxychilus cellarius,Oxychilus alliarius

Cochlodina laminata, Discus rotundatus and Arion ater agg. together with a very handsome Violet Ground Beetle, Carabus violaceus .


Time did not permit of any further work that day but I found it rewarding to know that this population is still very healthy. It is my intention to have a look at Well Copse and other likely looking compartments of adjacent woodland to see if there is a wider distribution.