Caper Whites

South Eastern NSW has recently experienced a massive migration of Caper White butterflies (Belenois java).  We came across this on 14 November when driving home from Rutherglen in Victoria where the insects flew across the highway in large numbers for several kilometres.  It was difficult to assess the exact direction as we moving approximately perpendicular to them.

 The movement is well known but according to an email from a butterfly expert is not well understood.  This second map summarises the suggested overall situation.

From reports to a local butterfly researcher, by 16 November the movement had reached the ACT and surrounding areas.  They were moving, in a North-easterly direction through our garden in the evening of that day, and numbers were still around on the 17th and 18th.  In the afternoon of the 18th I was able to get some images of them feeding - presumably on nectar - on Centranthus ruber (aka Kiss-me-quick) in our garden.

Despite the specific 'ruber' implying red there is a white variety C. ruber Albus.  The butterflies here are, I think, males.

We do have some red form of the flower, and the amount of yellow on this butterfly makes it a female.

Hopefully the amount of information being passed around about the movement this year will contribute in a small way to advancing understanding of the movement.

As a further point, a comment by Sue Catmint on an earlier post, notes that white butterflies, probably of this species, had turned up in her Melbourne garden.  So soe of them keep going South, rather than hooking back towards Canberra.