Lucy discovered a Saunders Case moth caterpillar (Metura elongatus) enjoying her apricot tree
The Curious Case of the Bare Apricot Tree Over a few nights a young apricot tree in my Beaumaris backyard was stripped of almost every leaf. I was perplexed. Were possums the culprits? Possums receive bad press in Bayside and are usually the first to frame when our fruit trees get mauled. When I discovered my stricken tree, suspicion fell on the ubiquitous ringtail possum (Pseudocheirus peregrinus). On closer inspection of the bare branches, I spotted a curious silken cocoon of small sticks dangling in the air. Unlike the discarded cases I had observed in the past, this one was plump and occupied. I plucked it off and was stunned when a few minutes later a boldly-striped, black and orange caterpillar the size of my ring finger partially emerged from the cocoon. I collected a few of the remaining apricot leaves and put the caterpillar in a large jar in the kitchen. That night, equipped with a torch I returned to the tree and discovered a veritable plague of the same caterpillars devouring what was left of the foliage from the safety of their cocoons. I carefully removed each one and added them to the jar.
A Google search and helpful Victoria Museum expert identified the apricot destroyer as Saunders Case moth caterpillar (Metura elongatus). These distinctive looking native creatures construct their tough cocoons from their own silk, interwoven with small twigs and other natural material. They remain inside the cocoons for safety, dangling from trees and fences when inactive, and revealing only the front portion of their bodies when moving about and feeding. For more than six months my caterpillar army thrived in the jar. When the apricot leaves ran out, I introduced others and found the caterpillars happily munched on a variety of native and exotic vegetation. I fully expected them to pupate after a few weeks but research revealed these strange creatures can live for as long as two years as caterpillars, with the females never leaving their protective cases. Only the males emerge to fly off as adult moths in search of females.
banksia bulletin — winter 2013
Armed with this knowledge, I decided to release my collection some distance from my recovering apricot tree. I had learned much in the meantime: • The portion of the body that remains inside the cocoon is a dull uniform colour in stark contrast with the vivid, visible part of the caterpillar. • The empty cases are so tough that even knives and scissors struggle to cut through them. • The caterpillars are mainly nocturnal. • They will eat a wide variety of leaves including eucalyptus and wattles species. • They are not generally regarded as fruit pests and should be treated with respect. • They are endlessly fascinating to children. Lucy Farmer Local Resident
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