Talking molluscs

Heading into autumn, moth-trapping along with general garden listing has started to slow down. As such I have started to turn my attention towards a TAXA group which I have previously only made the slightest of forays into exploring. Molluscs seem the obvious choice as conditions get wetter and cooler, and searching for them on damp nights when the moth trap is not running, maintains my curiosity, and scratches the "listing itch" at the same time.

Noting an interesting looking green and yellow slug on the wall, one night, towards the end of September, I thought it was potentially different to the Green Cellar Slug (Limacus maculatus) that I have recorded before. A long pale stripe running along the keel and tail, was not a feature that from memory I had noted on the few Green Cellar Slugs, I had already identified in the garden.

Having consulted the AIDGAP guide to the “Slugs of Britain and Ireland” (2014) I thought it might be a reasonable candidate for Yellow Cellar Slug (Limacus flavus); with a heavy dose of scepticism given that guide advises that dissection is often required to distinguish it from L. maculatus.

Limacus flavus

Posting the record on iRecord, I was surprised by the almost immediate verification of the species as L. flavus by Chris du Feu who also commented: “Thanks for the record. There is a long enough yellow streak from tail most of the way along the centre of the back to the mantle. It is likely to be a cross between L. maculatus and L. flavus. With L. maculatus being the dominant species at present, it is likely that these crosses become more and more like L. maculatus with each passing generation. Good to see a record which we can call L. flavus. They are becoming something of a rarity now.”

This prompt and considered response from Chris gave me no end of encouragement to pursue the trail (pun intended) of further garden molluscs. Over the next couple of weeks armed with the AIDGAP guides for both slugs and land snails, I stalked the garden looking for likely suspects.

Girdled Snail
(Hygromia (Hygromia) cinctella)

Kentish Snail (Monacha (Monacha) cantiana)

White-lipped Snail (Cepaea (Cepaea) hortensis)

Common Garden Snail (Cornu aspersum)

Large Red Slug (Arion (Arion) rufus)

Large Red Slug in cop.

Draparnaud's Glass Snail (Oxychilus (Oxychilus) draparnaudi)

Netted Field Slug (Deroceras (Deroceras) reticulatum)

Ambigolimax agg.

At work a colleague and I were felling small trees on the heathland. I became very excited to note several Tree Slug (Lehmannia marginata) along the length of a downed Birch (Betula sp.), and we carefully avoided killing them as the cord wood was cut and stacked.

Tree Slug

References

Cameron, R. (2008) 2nd Edition Land Snails in the British Isles AIDGAP Field Studies Council

Rowson, B., Turner, J., Anderson, R., Symondson, B., (2014) Slugs of Britain and Ireland AIDGAP Field Studies Council