Compared to the last two (very wet) summers, this butterfly season has been a huge disappointment. Not only have there been few of the more exotic species (e.g. swallowtails, Jezebels, glasswings), even the Common Browns and Xenicas that are usually abundant are seriously down in number.
To date I’ve seen, briefly, a single Orchard Swallowtail, two Dainty Swallowtails, some Wood Whites and Caper Whites early in the season, plenty of Cabbage Whites, of course and two days ago, an Imperial White (Delias harpalyce) aka Imperial Jezebel – which made my day. Though I’ve seen them on the Tableland before (notably, a week ago at Rocky Ned lookout, there were perhaps a dozen or more flying around the tree tops), they’ve never been as numerous as the Wood Whites (Delias aginippe) and I’ve not before seen them at our place. Yesterday, one was in the flower garden at an exotic flower, feeding on nectar.
This species uses Drooping Mistletoe (Amyema pendula) up here as a food plant and last year I took these photos of Wood White eggs that then hatched larvae; this species has the same food plant.
So, why the lack of butterflies this year? One local theory (suggested by local butterfly expert Ben Brook) is that butterfly parasites (and there are many kinds, particularly small wasps and flies) spent the last two seasons breeding up numbers and this season they finally caught up with their hosts. Or perhaps the lack of humidity and rainfall caused the decline. Whatever the reason, it’s been a less colourful and exciting year as a result.