In message , chris French
writes
Hi John,my garden is slug heaven.Trees along the western fence,so shady
early in the PM,and lots of leaf litter.I first used the nematodes about 6
years ago.They worked really well.So well that slugs where not a problem
the following year and only started to put in an appearance in numbers the
year after that.
I can only guess,but as they are native I managed to "seed" the area for
the longer term.

I understood the Nematode was not native at all, from New Zealand
originally?

You may be thinking of the New Zealand Flatworm, which has caused
problems in Scotland and Northern Ireland, by predating earthworms.
Nemaslug is Phasmarhabditis hermaphrodita which is said to be from
Central Europe.
--
Stewart Robert Hinsley