ORDER ORTHOPTERA 59 



the other members of the group, and instead of feeding upon 

 ordinary vegetation they secrete themselves in dark places 

 and feed upon debris or decaying organic matter occurring 

 in such i)laces. The character of the ovipositor is like that 

 of the crickets, but the head, antennae, and other parts 

 look like those of field locusts. The details of their life his- 

 tory are not fully worked out, but it is probable that there 

 is one generation a year. 



Family Gryllidae. — This family includes the crickets and 

 may be separated into herbivorous, carnivorous, and omniv- 

 orous forms. 



Oeccmthus, tree crickets. Oecanthus niveus, snowy tree 

 cricket, is most commonly referred to, but 0. fasciatus and 

 other species are more common. The larva? feed upon plant 

 lice and are distinctively carnivorous, and therefore are 

 serviceable during that stage. The adults may feed on flies, 

 but were formerly thought to be herbivorous. The adults 

 are found in autumn, and then they gather on various kinds 

 of trees, fruit trees, etc. The eggs are forced into the twigs, 

 forming a series of punctures. The eggs are deposited in 

 two rows. They are elongated in form, and the masses of 

 eggs include forty or fifty eggs depositerl by each individual. 

 The eggs remain in the twigs during the winter and are well 

 protected in that way. They are sometimes deposited in 

 galls on willows; if not by this species by one closely related. 

 Some eggs are forced into the stems of annual plants, Helian- 

 thus, Solidago, etc. The eggs hatch during the spring sea- 

 son and the larvse depend upon plant lice for food supply. 

 They grow to reach adult stage, when they probably feed 

 upon other insects. They are probably not destructive, and 

 the attacks upon plant lice make them valuable. .They are 

 rather desirable on fruit trees, only in some cases the punc- 

 tures of the twigs result in rather severe pruning. 



A quite common species on Helianthus is Oecanthus fas- 

 ciatus. There are four or five species that look a great deal 

 like the common forms. In the males the wings are broader 

 and very transparent. One form lays eggs in separate punc- 

 tures at different points. 



