Metura elongatus (Saunders’ Case Moth)Metura elongatus Male

The Saunders’ Case Moth (Metura elongatus), also known as the Large Bagworm, belongs to the Psychidae family.

The caterpillar of the Saunders’ Case Moth live and pupate in a silken casing. The early instar of the Saunders’ Case Moth initially cover their casing with bits of leaf. As they grow in their case, they attach parallel short twigs over the surface of the case. The amount of twigs attached to the casing most likely be affected by what is available in their immediate surrounding. The following photos appear to show the Saunders’ Case Moth with a fur-silk collar. As well as short twigs, some of the attachments to the outside of the case are paper-thin plant material.

Saunders' Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza
Saunders’ Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza

The caterpillar live and pupate within this silken bag case, providing it shelter and safety. When threatened, they temporarily seal the front opening of the case until the danger is past.

Saunders' Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza
Saunders’ Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza

In the natural environment the Saunders’ Case Moth are found attached to the plants they feed on. They are also often seen attached to walls and fences in urban settings.

Saunders' Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza
Saunders’ Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza

The case / bag of the Saunders’ Case Moth and many other species of case moths have two openings. There is the larger ‘mouth’ through which the caterpillar protrudes its head and thorax to feed and move, and a smaller hole at the other end of their shelter through which the droppings are ejected.

Saunders' Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza
Saunders’ Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza

Check out our Insects > Moths and some of the other different types of Case Moths, including our Ribbed Case Moth.


  • Scientific classification
  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Subphylum: Hexapoda
  • Class: Insecta
  • Informal: Pterygotes
  • Order: Lepidoptera
  • Family: Psychidae
  • Subfamily: Oiketicinae
  • Genus: Metura
  • Species: Metura elongatus
Saunders' Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza
Saunders’ Case Moth (Metura elongatus), west Sydney NSW © Murad Abaza

Footnote & References

  1. Saunders’ Case Moth (Metura elongatus), Images © Murad Abaza
  2. Australia – What Bug Is This? Facebook group, https://www.facebook.com/groups/Auswhatbugisthis
  3. Metura elongatus (Saunders, 1847), Atlas of Living Australia, https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:07c53617-7d4b-4256-9c96-f6f84d64afcd
  4. Metura elongatus (Saunders, 1847), Saunders’ Case Moth, Coffs Harbour Butterfly House, http://lepidoptera.butterflyhouse.com.au/psyc/elongatus.html
  5. Saunders’ case moth, Metura elongatus, Australian Museum, https://australian.museum/learn/animals/insects/case-moths/
  6. Metura elongatus, Wikipedia, https://en.wikipedia.org/wiki/Metura_elongatus

Metura elongatus (Saunders’ Case Moth)Metura elongatus Male

MothsMoths Index Aedia arctipennis Agrius convolvuli (Convolvulus Hawk Moth) Anthela guenei (Four-Spot Anthelid Moth) Austrocaligula engaea (Mistletoe Emperor Moth) Case Moths (Variety of Cocoons) Coenotes eremophilae Comocrus behri (Mistletoe Moth) Cosmodes elegans (Green-blotched Moth) Donuca spectabilis (White-spotted Owl-Moth) Four-spotted Cup Moth (Doratifera quadriguttata) Endoxyla cinereus (Carpenter Moth) Hippotion celerio (Vine Hawk Moth) Hyles livornicoides (Australian Striped Hawk Moth) Leaf Case Moth Metura elongatus (Saunders’ Case Moth) Ochrogaster lunifer (Bag-shelter Moth) Opodiphthera eucalypti (Emperor Gum Moth) Plume Moth Ribbed Case Moth Sameodes cancellalis Utetheisa (Rattlepod Moth)