ENTOMOLOGY IN OUTLINE LEPIDOPTER A. 79 



it is so pleasant to find one that does something toward redeeming its 

 reputation by being of some service in checking pests. 



Of the family Zygsenidse but few species occur in the United States, 

 and none are destructive to fruit trees. 



The family Chaleosiidse is represented by but a single insect, an 

 obscure moth known as Gingla later culde, found in Arizona. 



The family Thyrididse is a small one, and consists of small moths 

 characterized by the presence of small white or yellowish translucent 

 spots on the wings. 



The family Cossidse is of more interest to us, for in this we find some 

 of the most destructive of the moth family. To this belong the goat- 

 moths or carpenter-moths, as they are popularly known. In their larval 

 stages they live in the roots and trunks of trees and sometimes do great 

 damage to the tree which they infest. In some cases, in the East, 

 orchard trees have been killed in great numbers by the ravages of these 

 moths. They are said to remain in their larval stage for three years, 

 before they have attained their growth. They pass their transformation 

 in the burrows which they have eaten out in the wood, and when ready 

 for the change the larva forces itself partly out from the burrow. When 

 the moth has emerged, the empty pupa skin can be seen protruding 

 from the burrow. The species most common in California is Priono.rys- 

 tus robiix. It is a large gray moth, much resembling the sphinx-moth 

 in general appearance, and flies by night. They are destructive to 

 elms, locusts, and forest trees, but have not as yet been reported as doing 

 damage to fruit trees in our State. 



In the family ^Eg-eriidse we have the clear-winged moths a family 

 utterly unlike any other branch of the Lepidoptera, and many of the 

 members more resembling wasps than moths. They are of small size, 

 with slender bodies, and fly only by day and frequently in the bright- 

 est light. They are all borers, and among them are some of our most 

 destructive pests, the Western peach-root borer (Sanninoidea opal- 

 escens), the Eastern peach-root borer (S. exitiosa), the currant borer 

 (Alcathoe caudatum), and many others, being representative of 

 the family. Many of the matured insects are very beautiful, and most 

 of them are remarkable on account of their protective mimicry, resem- 

 bling, as they do, insects of different orders, especially bees, wasps, and 

 flies. This strong resemblance to stinging insects often protects mem- 

 bers of this family from danger to which their day-flying habits would 

 otherwise expose them. Yet, in spite of their threats of danger, which 

 are carried out in their acts as well as in their coloring, they are harm- 

 less, and it is all a mere bluff on their part to frighten their enemies. 



