Skippers are a family of butterflies which look as much like moths as like ‘real’ butterflies: they are smallish, heavy-bodied, mostly rather plain in colour, and often rest with wings spread. Their flight is often fast and abrupt (that’s where their name comes from) but when this couple flew-fell past me early yesterday evening they seemed quite out of control. Still, they landed on a pentas leaf and seemed happy enough there.
The family, Hesperiidae, comprises nearly a third of Australian butterflies. They are very easy to distinguish from other families but distinguishing one species from another within the family is quite difficult, especially working from photos – visit this collection of my older photos or this collection of all Australian species by Don Herbison-Evans and Stella Crossley to see why.
The couple above made identification easier than usual because I knew I had male and female of the same species. (That is one reason I take photos of mating pairs when I can; the other is that they tend to stay still longer than if they are just feeding.) They are Orange Palm Darts, Cephrenes augiades, and Braby’s big book of Australian butterflies says that, of ten subspecies worldwide, “only C. a. sperthias is found in the Australian subregion.”
Their larvae feed on the leaves of palm trees. The butterflies were native to the tropical east coast but they have been accidentally spread all around the country by people growing palms in their gardens. Their diet has expanded along the way, too: they have been recorded feeding happily on more than 100 exotic (i.e. introduced) species of palms.
When we think of horned males fighting over females most of us will think first of deer. All those dramatic photos of rutting deer with locked antlers have to have their effect, I suppose, but it’s a bit bizarre that are we are so conscious of exotic wildlife and forget our own.
Of course, our own horned battlers are a bit smaller – not crocodiles or kangaroos, not even koalas or quolls, but insects. I wrote about the Rhinoceros Beetle a month ago. They are quite big enough to impress onlookers. Then I came across something much smaller still and completely unexpected, a tiny fly with the same equipment which it uses for the same purpose. Meet Wawu queenslandensis:
He’s smaller than an ordinary domestic fly but he is colourful and well-armed, and fights for females just as Rhino beetles and deer do. He has a cousin, slightly smaller but even more fearsomely (to other flies) equipped; a photo of a dead specimen is here and the pin will give you an idea of just how small he is. Females, by the way, are hornless, as they are in Rhino beetles and most deer.
It makes one wonder just how far back in the evolutionary line some kinds of behaviours really go. Do deer do it because their ancestors all the way back to the common ancestor of deer and flies, hundreds of millions of years ago, have done it? Or has it evolved separately several times, as some other features have?
Sometimes it seems unfair, sometimes it seems like poetic justice for being too sure of yourself: you write something like ‘still no Eurema butterflies’ and take it public on your blog, then you walk outside and see not one but two Eurema butterflies, and they are busily making even more little yellow butterflies. Can’t complain too much, though – they waited for a photo:
They are noticeably smaller than the majority of our common butterflies (e.g. Crow, Chocolate Soldier or Eggfly) but larger than the little Zebra Blues which hang around the plumbago bushes.
These butterflies are difficult to identify down to species level and I have fallen into the habit of just thinking of them all as ‘Eurema’, which is the genus they belong to. I know they are either E. alitha or E. hecabe but the two species are very similar to each other and, to add to the difficulty, their coloration is seasonally variable. With those caveats, I will say I think these two are E. alitha, dry season form, with the male above.
The fact that they are dry-season form may be an indication of just how little rain we have been getting.