The Small Green-Banded Blue (Psychonotis caelius) is a small but very attractive Lycaenid butterfly. It is found on the East coast of Australia from the tip of Cape York as far South as Wollongong in NSW.
Although it’s not widespread in the Sydney area, there are colonies in places where its main foodplant Alphitonia excelsa (Red Ash) is found in sufficient quantity. One such site is at Brooklyn, just 50kms from Sydney’s CBD.
The spot where I’ve had most luck finding Small Green Banded-Blues at Brooklyn is only about 100m from the Hawkesbury River train station; it’s marked with the blue “bug pin” on the map below. The photo at the top of this blog post was taken here, right next to parked cars at the bottom of a wooded bank. Unsurprisingly, a lot of the trees growing on that bank are Red Ash.
The yellow bug pin shows where caelius can be seen flying in amongst the trees; I’ve often seen them settle on leaves at the edge of the footpath around here.
The two black bug pins indicate spots where I’ve seen caelius feeding from lantana flowers along the edges of the grassed areas adjoining the bushland.
I’ve had best results going to Brooklyn in April and around Australia Day. When I went there in April 2010 I was probably a week or two late, as the specimens I saw were a bit worn (as you can tell from the photo above). I suspect early April might be a better time to find fresh butterflies, though no doubt it varies from year to year.