A Fading Flutter: Melbourne's Endangered Butterflies and Moths

This is a guest post by Mackenzie Kwak.

There is perhaps no greater dichotomy in the public’s mind than that of the butterfly and the moth. While the butterfly is admired for its bright colours and gentle flutter, the moth is despised for its often dull wings and seemingly erratic flight. The distinction between moth and butterfly, though, is often difficult to grasp. Superficially many colourful day-flying moths are mistaken for butterflies. To the average person, moths are the ugly sisters of butterflies, so uncommon and few that they needn’t even have common names. 

However, in reality butterflies are merely a small branch comprising five colourful families in the mega-diverse tree of moths, which contains more than 180,000 named species, collected into approximately 126 families. Many species remain unknown, and chances are high that if you look out of your window on a warm, overcast night, at least one of the many moths congregated on the glass will be unnamed. Unsurprisingly, many species of moth and butterfly which have been studied well enough are recorded as threatened in Victoria. In fact, eight of the 14 insect species listed as Critically Endangered in our state are moths or butterflies. 

Emerald moth. Image: Wiki Commons

Emerald moth. Image: Wiki Commons

Perhaps the most well-known of our state’s threatened butterflies is the enigmatic Eltham copper butterfly (Paralucia pyrodiscus lucida), which was thought to be extinct until it was famously rediscovered in 1986. It has an extremely complex life cycle and lives in close association with its larval host plant, sweet bursaria (Bursaria spinosa), and ants of the genus Notoncus, which tend to its caterpillars. If either of these essential associates is absent, the butterfly will also be. While found primarily in the township of Eltham along Diamond Creek, small populations also exist in scattered locations across the state. 

However, the species has been mired in controversy of late (the quiet type that only a handful of entomologists remark upon amongst themselves). The Eltham copper butterfly was originally described as a distinct species (Paralucia lucida) before being downgraded to subspecies rank (Paralucia pyrodiscus lucida). However, recent findings have suggested that it does not possess the distinctiveness to warrant even the rank of subspecies, and some authorities now only consider it to be a race of the more common fiery copper butterfly (Paralucia pyrodiscus). Many conservationists, however, aware of these recent taxonomic changes, still consider this butterfly to represent an evolutionarily significant unit (ESU) worthy of conservation. 

Overshadowed by the wide public awareness of the Eltham copper butterfly is the critically endangered small ant-blue butterfly (Acrodipsas myrmecophila). The small ant-blue, like its name suggests, is an inconspicuous little species which spends most of its life deep in the nests of ants. The caterpillars are peculiar in that unlike many other caterpillars, which live on plants, this species live in the nests of the coconut ant (Papyrius nitidus). The peculiarities don’t stop there, though, as the little caterpillars are ant-eaters, technically termed myrmecophilous by entomologists. Like Eltham copper butterflies, if they lose their ant associates, they quickly disappear from the environment.  

Native butterfly (Painted Lady). Image: Wiki Commons

Native butterfly (Painted Lady). Image: Wiki Commons

Perhaps the most threatened of the native moths to call the greater Melbourne region home is the golden sun-moth (Synemon plana) which gets its name from the striking golden orange hindwings sported by the adults. It has also been subject to the most intensive conservation efforts compared with its equally threatened sister species, the orange sun-moth (Synemon nais), reddish orange sun-moth (Synemon jcara) and the small orange spotted sun-moth (Synemon discalis), which are also regarded as Critically Endangered in Victoria. 

The golden sun-moth formerly inhabited the vast volcanic plains grasslands which stretched thousands of acres west of Melbourne, and the grassy woodlands which skirted Melbourne city until they were converted into pasture and later urban sprawl. The moth is now in decline and almost extinct, save for a few scattered populations around the greater Melbourne region. The caterpillars are rather strange, in that they do not eat the foliage of their native grass food plants, but instead eat their roots! The adult moths are remarkable as well as they do not feed at all; instead they frantically seek out a mate before producing eggs on native grasses and dying. 

Orchard Swallowtail. Image: Wiki Commons

Orchard Swallowtail. Image: Wiki Commons

Unfortunately we are too late to save some of Melbourne’s butterflies and moths, which in the past century have disappeared from our little place in the world. The bright-eyed brown (Heteronympha cordace wilsoni), orange ringlet (Hyposysta adiante), and the cryptic sun-moth (Synemon theresa) have all vanished from Melbourne. However, there are small things we can all do to ensure butterflies and moths flourish in our city! 

Perhaps the most helpful thing you can do is plant indigenous species, which provide food and shelter for caterpillars, and nectar for adult butterflies. Some common food plants which look great in the garden and are largely drought-tolerant include paper daisies (Xerochrysum spp.) and tussock grasses (Poa spp.). They also have the added bonus of being extremely well adapted to the climate and soils of the greater Melbourne region. 

You may also like to get involved with local environment groups like ‘The Friends of Merri Creek’ who have done much work to enhance local habitats along the Merri Creek for one of the few remaining populations of golden sun-moths. Last and most simple is to get to known our local butterflies and moths a little better and champion their conservation in the local community! Tell a friend or a neighbour what you have just learned and get people talking about these remarkable locals!

Header image courtesy of Wikimedia Commons.

Mackenzie Kwak is a zoologist with a broad interest in Australia's diverse flora and fauna. His research focuses on the biogeography, systematics and ecology of Australasian ectoparasites, particularly ticks, fleas and lice.