I must admit, however, that for most of my life until now, I (like many other people) saw them as a pest eating my cabbage and lettuce plants. Since taking up photography in a serious way, and developing a huge love of butterflies, I have seen their splendour through different eyes.
From the first day I took a photo of a White Butterfly with my macro lens, my love affair with these much maligned butterflies began. By laying their eggs on host plants for their caterpillars to feed on and grow into butterflies, they are only doing what nature has hard-wired them to do. That we like to eat cabbages, lettuces and similar, is certainly not the butterfly's fault.
The small white (Pieris rapae) is a small- to medium-sized butterfly species of the whites-and-yellows family Pieridae. It is also known as the small cabbage white and in New Zealand, simply as white butterfly.
The names "cabbage butterfly" and "cabbage white" can also refer to the large white.
The butterfly can be distinguished by the white color with small black dots on its wings. They are distinguished from the smaller size and lack of the black band at the tip of their forewings.
Ref: Wikipedia
The White Butterfly is suspected tho have first arrived in New Zealand in the summer of 1929-30. It was first recorded in Napier in March 1930.
It quickly spread throughout New Zealand by the autumn of 1936, however there seems to be 'jumps' in its dispersal over those few years. For example the first specimen in the South Island was in the port town of Timaru, not in the Marlborough region as one would expect by natural dispersion.
The logical conclusion is that some specimens where transported around the country along with our shared food of the cabbage family. This is the way it is suspected that the White Butterfly made it to New Zealand (just like North America in the years before and Australia in the years after). No one is sure whether the New Zealand stock came from Hawaii, North America, Europe, Asia or a combination, but most likely it travelled as a pupa in diapause as this would give it the best chance of surviving in a cold store.
It is recorded as having up to 5 generations a year in the north and 2 generations in the south.
The White Butterfly is considered a pest in New Zealand, so several parasites (Ichneumon's, the wasps Pteromalus Puparum and Apanteles glomeratus) have being released to control it.
Unfortunately they are negatively effecting other species of butterfly, especially the Red and Yellow Admirals and the Monarchs.
The White Butterfly has characteristics not seen in other New Zealand Butterflies, namely the aforementioned diapause, a seasonal difference in size, and less black markings on the spring generation.
The Maori name "Pepe Ma" is translated from the English name.
Ref: NZ Butterfly Info