22 Aug Does this Look Like a Moth to You?
By Dr Jean Holley, UNE Discovery Voyager
I found this beauty in my backyard a few weeks ago. I knew that it was a case moth, but I wasn’t too sure which species it might belong to.
Many people would have seen a case moth case at some time or another, but fewer people may know what they actually are. So, before we look at the exact species I have (and how I found that out), let’s have a look at case moths in general. As the name suggests, case moths are moths, and belong with the butterflies in the insect Order Lepidoptera. Case moths belong to the Family Psychidae within this order. There are about 200 species in the family. In most species, the caterpillars reside in a mobile home, made from silk, leaves and/or sticks, and the cases can be used to identify the species. Caterpillars feed on foliage. After becoming adults, males will fly in search of females, who generally stay in their cases and do not develop wings (Zborowski and Storey 2017).
On a quest to find out what species my case moth belongs to, I took a photo of the case, including a ruler to show scale, and uploaded my photo to iNaturalist Australia. iNaturalist is an online social network where biodiversity information can be recorded and shared. Observations submitted to iNaturalist Australia are added to the global iNaturalist database. These observations are also shared with the Atlas of Living Australia (ALA) and the Global Biodiversity Information Facility to help scientists find and use data. You can find out more, and even sign up, here.
So back to our case moth. After only a few minutes from uploading my image to iNaturalist Australia, an identification was suggested for the case moth by an iNaturalist member. The species is the Saunders’ case moth, know scientifically as Metura elongatus. Adult males have black wings, an orange hairy head, and a black and orange banded abdomen. Adult females are white with a brown head, have no wings, and remain in the larval case (Murray 2020). The front part of the caterpillar of this species is orange and black, while the rear part is cream coloured. Caterpillars uses silk to construct an elongate, spindle-shaped case, to which they attach short lengths of slender twigs at widely spaced intervals (Hubregtse 2011). According to Hubregtse (2011), before a caterpillar pupates, it attaches its case to a secure support by a tough band of silk. I found my case moth on the grass, so it would seem that it has become detached from its support. I have now stowed it away safely in the top of a large pot in our backyard to protect it from the lawn mower. I’m very curious to see what will eventually emerge. According to Hubregtse (2011), if the moth is a male, he will emerge from his case in Spring. If it is a female, she will have no wings and remain in her case.
So, I will add this new discovery to the list of things that I am watching and waiting for as Spring approaches: the flowering of the wisteria, our apple trees waking up after Winter, and now the emergence of a case moth squirreled away in a pot! I know these are seemingly little things, but it connects me to nature in my own backyard, and this is something that I always find great solace in doing. See what you can discover in your own backyard, and if you are feeling extra curious, I encourage you to visit the iNaturalist Australia website to share and learn more about your discoveries!
References and further reading:
Hubregtse, V. 2011. Some observations of a Saunders Case Moth Metura elongatus larva. Victorian Naturalist. 128: pp. 90-91.
Murray, M. 2020. Saunders’ case moth. Australian Museum. https://australian.museum/learn/animals/insects/case-moths/. Updated 08/12/20. Accessed 16 Aug 2021.
Zborowski, P, Storey, R. 2017. A field guide to Insects in Australia. 4th Edn. Reed New Holland Publishers. Sydney, Australia.