Rog Standen

While seeking to find out what insects were feeding in our garden, I was pleasantly surprised to find around twenty different species of flies were coming to the daisies in our front yard, But the highlight for me was finding a large (about 13cm long) case of the Saunder’s Case Moth (Metura elongatus), also called Large Bagworm, from the Psychidae family. These moths are found in eastern Australia including Tasmania. Lee tells me that they are seen occasionally in the area so whilst a first for me, it is not unusual.

Larvae live and pupate in a silken shelter that is covered in bits of leaf initially but then bits of twig are added as the larvae get bigger and mature. It is a very complicated and time-consuming process to cover the case with these twigs. As they grow and the case is extended at the ‘head end’, they cut a piece of twig off with their jaws and attach an end to the mouth of the case with a few strands of silk. They then withdraw into the case and cut a slit in the wall (this can take an hour) through which they protrude their head and thorax. They then grasp the end of the twig and cut it free from where they tied it, after which they withdraw back into the case and sew the end into the wall with silk (the whole process can take 1.5 hours - per twig).

The larvae feed on a wide range of plants, including tea-tree, some eucalypts and some ornamentals. The effort it takes to haul the case up trees was impressive to watch, overcoming bark obstacles with care and strength. The three pairs of legs on the thorax, combining with the jaws enabled the tree to be gripped securely. Also, the prolegs of the inner abdomen must have a good grip on the silk lining to securely hold the inside of the case because the caterpillar never looked like slipping out of the case.

Adult females have no wings and remain in the case when they hatch. They mate there and lay their eggs (thousands) then die. Females tend to make larger cases (12-15cm) that are generally longer then the male’s cases. ‘My’ case therefore was probably a female. Males have black wings, a black and orange abdomen and an orange head. They look stunning in the photos I have seen. He has a long abdomen that is telescopic (hence the name ‘elongata’), much longer than the wings, presumably to reach in and copulate with a female. Mating takes place though the hole at the ‘tail end’ of the female case.

Only the head and thorax have a chitinous covering and the off-white abdomen is unprotected and remains within the case at all times. Pupation can take from a few weeks to a few months depending on the weather.

I watched the case I found as it had not moved for some days that indicated to me that it had started to pupate. I was hopeful that I might see a male come in search of the female when she hatched, but alas, the case disappeared one day. I can only assume either the larva was still growing and went in search of more food or that it was taken by a bird or other predator. Either way, I am yet to see an adult Saunder’s Case Moth.

The technical information was mainly sourced from the Queensland Museum website fact sheet on case moths.

Right: Mistletoebird, Tawny Frogmouths

Pat Gomm

During the SEANA camp on Phillip Island in November2011, one of the many excursions aranged was Frogging and Spotlighting at Swan Lake led by Robin Drury. 1nterested people assembled at 7.15 pm, car pooled and drove to the car park at Swan Lake to meet with Robin. The night was cool and dark, with threatening rain. We walked, armed with torches, to the Mutton Bird Rookeries at Summerland Bay. We stopped at two bird hides accessed by a long board walk. As Robin pointed out various frog calls, the Shearwaters flew in, creating a swirling, crescendo screeching mass of birds as they searched for their burrows and mates. The noise was terrific, drowning out the frog calls. It was a wonderful experience to see the shearwaters so close, some landing near our feet, some flying so close over our heads. By torch light, we could see them entering their burrows. The Short-tailed Shearwaters arrive at South Eastern Australia in October to breed, then migrate to the North Pacific in April. Also, we disturbed Welcome Swallows that were nesting in the bird hide. On our walk back to the car park, we spotlighted Ring-tailed Possums. It was a great excursion.