Common Brown Butterfly Heteronympha merope
What do they look like?
As adult butterflies, the males and females are very different! Like many butterflies, the female is larger and more strikingly-marked. She has dark upperwings with large orange blotches. The males have a finer pattern on their upperwing.
You will notice more females in autumn (March, April) and more males in spring and summer. That is because the males are active low over grasses in spring and summer. The females at that time are resting in cool shady places, so less obvious. Later in season the males start flying higher, at treetop level – and they are harder to see. After the males mate they die, so by autumn there are almost no males, only female butterflies to be seen in your backyard.
As caterpillars they are very secretive – hiding at the base of their food plant (usually a native grass) and emerging at night to feed. They are usually green with rows of black spots or dashes.
See the caterpillars here: http://lepidoptera.butterflyhouse.com.au/nymp/merope.html
What do they eat?
The adult butterflies like moisture and sweet liquids from flowers or insects. They can be seen feeding on tea-tree flowers and Bursaria flowers, and also on sap on tree trunks.
Their caterpillars love native grasses including Weeping Grass Microlaena stipoides, Kangaroo Grass Themeda triandra, and poa species including Coast/Blue Tussock Grass Poa poiformis.
Where do they live?
Common Brown Butterflies only live in south east Australia, Tasmania and a small area of south west Western Australia. They are the most common native butterfly seen in the backyards around Melbourne & Geelong.
How are they going?
They seem to be common, but they are emerging 10 days earlier as a result of climate change.
Read more about Common Brown Butterflies at this fantastic site: https://sabutterflies.org.au/nymp/merope.html
Other butterflies you could confuse them with:
The Yellow Admiral Vanessa itea is quite similar to a female Common Brown, but is more often flying in the treetops. The Australian Painted Lady Vanessa kershawi has similar colouring, but is more common in Spring. They have several eye-spots ontheir lower wing. The introduced Monarch butterfly Danaus plexippus is not that similar, has lines on the wings, and is not common around Melbourne & Geelong backyards.
This is part of a series “What’s In My Backyard? Flora & Fauna around Melbourne & Geelong, Victoria Australia” run by Koala Clancy Foundation in response to COVID-19. Koala Clancy Foundation is a koala-focussed charity based around the You Yangs, Victoria. A large part of our mission is local education, about koalas and all their animals and plants that live with them. Due to the coronavirus we can’t conduct our regular, educational Koala Conservation Days, so we are bringing that information online.