Caper White Butterflies have taken over

In the last week and a half, Robertson has had a break of hot steamy weather (at least in the mornings) then thunderstorms or rain, or sometimes even cold drizzle and mist (as now). Point is it has been very humid.
The locals say this is "getting back to normal" for Robbo. What has changed, that which I have noticed, anyway is the arrival here of the Caper White Butterflies. (Belenois java)

Something of a lucky shot.
Click to enlarge.
You can see the rolled up proboscis being unfurled
as the insect prepares to feed.

Yes, we still get the lots of the introduced pest Cabbage White Butterflies (Pieris rapae) because Wild Turnip is a prolific weed here. It is a member of the "Cabbage family" and they are all host plants for that Butterfly.

The other Butterfly we are also noticing, with the bright ochre and cream patches in its wings, is the "Yellow Admiral" (Vanessa itea) . Back to the Caper Whites - one of their little mysteries is why they undergo huge migrations which take them away from their "food plants". Like many Butterflies, the adults can feed on on nectar from a variey of plants.

Here the Butterfly is seeking nectar from a Westringia.But the Caterpillars are not so adjustable, and need specific plant families to successfully draw their nourishment from (as Caterpillars).

Females have a large area of black
around the edge of the upperside of the wings.

Don Herbison-Evans says (on his wonderful Lepidopteran website): "The food plants only grow wild in the northern two-thirds of continent, including: # Brisbane, # New South Wales, and parts of # South Australia. In spite of this, the Caper White butterfly frequently migrates south in summer.

In October 1998, mass migrations occurred in Sydney. Such migrations to Victoria happen sporadically. Migrations to Melbourne for example have been observed in November and in January. There are only a few Caper trees in Melbourne, and it is interesting that the butterflies locate these particular trees and lay eggs on them. How the butterflies find these few trees is unclear."

He adds: "The male and female Caper White butterflies appear to migrate separately."

Later in the same day as when I took the first images, I was at Mount Gibraltar, and I noticed a chase sequence.

A male Caper White Butterfly
(note the fine black border to the wings)
chasing a female.Well, the do seem to find eachother,
even if they catch different planes (so to speak)
as they fly south,
to our cooler climate.
Even if our area is without food for the caterpillars,
clearly it doesn't deter them from attempting to mate.

This male did not manage to achieve the normal "position".
The female flew away, with the male still in hot pursuit.

"Tale est vita"
(Such is Life).