Larva ID

[gwang]

Hi,
I just caught a caterpillar and am having little luck in identifying it.
It is about 4cm long with a black lengthwise stripe down the centre.  On
each side of this, there is a yellow stripe about 3/4 the width of the
black stripe.  The is then followed by an area on each side of a zebra
like pattern of black and white.  Then comes another yellow stripe
reaching almost to the feet and prolegs.  The rest of the caterpillar is
white with interdispersed black dots.  The head and feet are orange.
 
The plant it was found on had not yet been identified, but I suspect
is's a member of the mustard family.
Anyone out there have any ideas as to what this might be???
 
Thanks in advance,
Xi Wang