The Pine White Butterfly can be found from southern British Columbia and Alberta to Southern California and northern Arizona. It can not be found north of Vancouver Island in the coastal regions. The White Pine forewings are white on the uppersides with heavy black markings on its wing tips. The veins on the underside of the wings are also black. The female’s hindwings are faded in colour and sometimes edged in red and yellow.
You can sometimes see them high above old pines fluttering in the wind. Some consider them to be a pest as the caterpillars will occasionally strip a tree of its needles. The males fly around looking for females. After mating, the female will lay small green eggs in a row on a single conifer needle. The eggs overwinter and hatch into caterpillars in the spring when foliage begins to emerge. Most of the ones I have observed feeding were on wild daisies. One must assume that they are a boost to pollination for these flowers.
The caterpillars are dark green with white backs and side stripes. After hatching, they feed in groups until they get a bit older and then feed separately. They will go through 5 stages of development before they are ready to pupate. At this stage, they will drop down to the forest floor on long silk threads. Sometimes you can see many of them as they drop. 16 days later they will emerge as butterflies.
The Pine White Butterfly feeds on the nectar of flowers in our coastal forests. The caterpillar eats the needles of Pines, Douglas Fir and True Fir. Look for the butterflies in September when they have their only flight. They can also be found in fir forests.
Hi Bud,
This is a Pine White.
Thanks for the headsup Mike.