THE TUSSOCK MOTH 167 



and providers. As the Tussocks devour the leaves of 

 the shade trees, it is satisfactory to reflect that tiny 

 parasites are devouring them. Only a few will survive 

 to fulfil their life mission. 



They grow by coming out of themselves — by 

 casting off their outer covering, head, legs, plumes, 

 and tufts of hair. From the inert larva thus cast off 

 another emerges, with new head, legs, tufts, decora- 

 tions, and markings, larger and brighter than the 

 outer form that surrounded it. This change takes place 

 two or three times during the few weeks of larval 

 existence, and then the full-grown Caterpillars spin 

 themselves grey, comfortable cocoons for the brief 

 sleep of their pupal state. Some find a comfortable 

 place in the cloth bands set about the trees to entrap 

 them ; but of the pupae thus collected and burned 

 the great majority are already doomed to death by 

 parasites — ^the little beneficial insects thus mistakenly 

 destroyed. It is not in human affairs alone that we 

 injure ourselves and our friends by the pursuit of 

 our supposed enemies. 



Some of the well-fed larvae are too indolent to 

 descend the trees, and sleep in the upper branches, 

 but the more adventurous make a limited migration 

 from tree to tree. Females choose the trees which will 

 supply food for their next season's brood, while the 

 males, rejoicing in the prospect of winged flight, are 

 satisfied with any crevice in a fence or wall. The 



