Out and About in Your Garden

Varied Eggfly (Hypolimnas bolina) female
Photo: L. Beaton

Naturalists can't stop natting and social distancing doesn't mean you can't get 'up close and personal' with the natural world in your garden. Everybody has seen the explosion of butterflies and moths recently. This is a good chance to enjoy them.        
This butterfly is a native of Madagascar, India, South-east Asia, Australia and New Zealand. Here we call it a Varied Eggfly or, even worse, a Common Eggfly. A rather banal name for such a lovely butterfly. In New Zealand they're called Blue Moon and seeing a male's colours catch the sunlight, it is not surprising.

Varied Eggfly (Hypolimnas bolina) male
Photo: A. Podlich

The males' white markings are supposed to look like eggs; hence their name. Varied is because the females vary in pattern. Usually they have an orange patch on their fore wing, but can be from no orange markings (rare) to orange on both fore and hind wings. While Kiwis believe the bright blue circular patches resemble the full ‘blue moon’ in the dark sky.            
However, could their name be linked to the fact that the females are so particular with their eggs. They very carefully select the leaf on which to lay them. Scientists believe they are checking the plant is free from predators such as wasps and ants. Then they are one of the very few butterflies or moths to guard their eggs and sometimes even the newly hatched larvae. Not all females do this but the survival rate is better when they do.
The males also guard the host plants, defending their patch by chasing off unwelcome butterflies of any species. They will even investigate large mammals that enter their territory, often landing on humans.

Photo: L. Beaton

The caterpillars eat a variety of plants, including Sweet Potato and Eggplant leaves, as well as native and exotic weeds. They feed at night and hide away from the plant during the day.

Although they are butterflies of the wet tropics where they fly all year, they have also been recorded in arid areas such as western Queensland and even Alice Springs!

Acknowledgements:

"Butterflies of Australia" I.F.B. Common & D.F. Waterhouse 1981

"Australian Butterflies" Charles McCubbin 1985

"The Complete Field Guide to Butterflies of Australia" Michael F. Braby 2004

http://lepidoptera.butterflyhouse.com.au/nymp/bolina.html Coffs Harbour Butterfly House

https://www.sciencedirect.com/science/article/abs/pii/S0003347288802136 "Animal Behaviour" Volume 36, Issue 5, September–October 1988, Pages 1425-1431

https://www.lfwseq.org.au/blue-tiger-migration/ Deborah Metters

https://australianbutterflies.com/the-common-eggfly-butterfly-10-incredible-facts/ Australian Butterfly Sanctuary

https://www.projectnoah.org/spottings/19494200 Project Noah

https://www.butterflyidentification.com/blue-moon-hypolimnas-bolina.htm Butterflies in USA