Dear Peter
I agree with the determination as Limacus maculatus. The colouration can be variable between this and L. flavus but the latter is generally paler and has a pale stripe on the back. The size of the body tubercules is another useful character and your specimen has coarse tubercules, further supporting L. maculatus.
L. maculatus is widespread in Essex but has achieved this very rapidly, in just a few years. The spread has been so rapid that NBN has not been able to keep up (though I am surprised there are no records shown for Essex as I have submitted some myself) and the recently published new slug book even admits its distribution map for the species is out of date.
L. flavus has been rather outcompeted by L. maculatus and is now rare in Essex, as they tend to both enjoy the same manmade habitats (homes and gardens), whereas L. maculatus can achieve huge numbers, including in my garden.
I would be interested to make a note of your record if you could supply the relevant data.
Kind regards
Simon Taylor
EFC Mollusc Recorder
abmanuk@hotmail.com
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The weblog below is for naturalists to use to report interesting sightings, ask questions, report on field meetings and generally post pictures and any information or questions generally relevant in some way to the wildlife and geology of Essex. You will need to register and be logged-on to post to the forum, and you need to upload pictures first, for use in posts. Find out more