In article ,
Malcolm wrote:
In article , Kay
writes

I think they are cabbage whites, at least the ones on our nastursiums are
the same as some of the ones shredding our cabbages.

The term "cabbage white" actually refers to three different species,
Large White, Small White and Green-veined White. The caterpillars of all
three species feed on cabbages and most other brassicas, and also on
nasturtiums, among other plants.

We live and learn! I always thought cabbage white was the large white,
and the small white and green veined white were different - I'd
certainly never have referred to either of those as 'cabbage white'.

No, I'm sure you wouldn't and nor would others who have your knowledge
of our fauna and flora, but "cabbage white" is, in my experience, very
widely used as a generic term meaning any white butterfly(1), and as
such is just as imprecise as the term "seagull"!

Precisely.

It is correctly used as a generic term for any whitish butterfly
whose caterpillars live on cabbages, but the most common meaning
is for what you call the large white (i.e. just that one).

(1) My own parents were certainly guilty of this until their budding
(and doubtless irritating) naturalist of a son put them right!

Or put them wrong.

The English language is defined by its usage, and the OED confirms
that the experiences of most people posting to this newsgroup are
typical of English usage. And therefore correct. Real scientists
use scientific terminology when they want to refer to precise genera,
and accept that common English taxonomic terms do not necessarily
map to zoological taxonomic ones.

It is NOT incorrect to use the term with either of its common meanings.

It IS incorrect to use the term as a synonym for the genus Pieris.


Regards,
Nick Maclaren.