304 LIFE STORIES OF AUSTRALIAN INSECTS. 



Another time we made a case of flannel in the form 

 of the Metura case. AVe removed the larva from 

 its own case and left it overnight. In the morning 

 we found it was comfortably within the flannel 

 case. Then we placed its own case back again. 

 It vacated the flannel one and went back in its own 

 case. We split open the flannel case, and found it 

 was lined Avitli a layer of silky threads. 



Parasites: These caterpillars are frequently para- 

 sitised by flies and wasps, in spite of the protection 

 of the case. The eggs are laid, and the larvae 

 (maggots) feed on the juices of the caterpillar, and 

 finally spin little brown cocoons, w^liich are fre- 

 quently found beside the remains of the victim 

 within the case. (Plate 37, Fig. 3.) We have 

 found in nearly every instance the parasite is 

 a tachinid fly. In one large Metura case we counted 

 130 pupal cases of such flics. 



Tlie Metura elongata has a very long existence 

 as a caterpillar — a year, and they can live 

 v/ithout food supply for months. Thej^ are some- 

 times a serious pest in orange orchards, for they 

 oat quickly and largely. The food is varied, not 

 l)eing confined to one or fcAv plants. 



