354 TEXTBOOK OP ZOOLOGY 



and deposit the eggs to the depth of an inch or more. The eggs 

 are covered with a frothy substance which protects them from 

 moisture and, to some extent, from the frost. The eggs are laid in 

 the fall and hatch in the spring of the year. The development of 

 the grasshopper is by gradual metamorphosis. 



THE JUNE BUG 



The June bugs or May beetles are members of the family Scara- 

 baeidae, a very large and important family of beetles. More than 

 one hundred and twenty-five species of these beetles have been 

 reported as occurring in the United States and Canada, the majority 

 of them being considered as pests. The larvae or white grubs live 

 underground, destroying the roots of grain, cereal, truck, and gar- 

 den crops, as well as great tracts of pasture and grasslands. The 

 adults live upon the leaves of many kinds of trees and shrubs, often 

 completely defoliating the trees. Because of the general distribu- 

 tion of these beetles, they have been selected as a type to illustrate 

 the characteristics of Coleoptera, the largest order of arthropods. 



An examination of a specimen of the genus Phyllophaga reveals 

 that there are three body regions: the head, thorax, and abdomen. 

 The rather small, retracted head bears antennae of nine or ten 

 joints and a club composed of three elongate leaflike joints. The 

 antennae are located just beneath the lateral edge of the prominent 

 clypeus. The compound eyes are on the sides of the head near the 

 prothorax. There are no ocelli. The mouth parts are of the biting 

 type, similar to those of the grasshopper. 



The thorax consists of three segments. The metathorax is fused 

 with the first abdominal segment and with the mesothorax, leaving 

 the prothorax free and movable. Attached to the dorsal portion of 

 the mesothorax are the fore wings that are modified into horny 

 sheaths, or elytra, which cover and protect the back of the thorax 

 and abdomen. The hind wings are membranous and folded under 

 the elytra. The legs are well developed, the prothoracic ones being 

 adapted for digging in the ground. The thorax is provided with 

 yellow setae. 



The abdomen, which is broadly fused with the metathorax, consists 

 of eight external segments. When the elytra are removed, the 

 spiracles may be seen in the lateral margins of the dorsal surface of 

 the abdomen. The genital organs of both sexes are simple. 



