www.nzbutterfly.info. There's lots of information about all of New Zealand's butterfly species. You can now also view live NZBRN distribution maps for each species from the webpages of www.nzbutterfly.info.
For example, if you go to the red admiral page, you'll see an NZBRN logo on the right-hand column. Clicking it will pop up a map showing all red admiral observations in NZBRN. Handy!
If you want to add maps like this to your own website, we have a blog post of instructions all about it.
The other thing you'll note if you explore these maps is that we need a lot more observations to properly map out the distributions of these butterflies. Get ready to spot butterflies in the spring, and if you have any old butterfly observations, please consider sharing them with the world using NZBRN.