240 



INJURIOUS AND BENEFICIAL INSECTS I >F CALIFORNIA. 



Barbara County and the northern part of the State by Dr. Edwin C. 



V;m Dyke. 



Food Plants.— "Dr. E. C. Van Dyke records const live oak as the 

 normal host plant, II. A. Weinland found large numbers of acacia trees 

 infested and D. W. Coquillett bred adults from dead grapevine canes. 

 Living and dead tissues are attacked. 



Control.— Cutting out and burning the infested branches as soon 

 as the work is observed in January and February is the best means of 

 control. This i.s to be recommended only for small gardens or parks, 

 and tiol for woodlands or wild areas. 



SCARAB^EID^ (Family) 



LEAF-CHAFERS, COCK CHAFERS, JUNE BEETLES, SCAVENGER BEETLES, 



TUMBLE BUGS 



This is a large family of beetles which vary greatly in size, color 

 and habits. All are characterized by having the antennae elbowed and 



terminating in an enlarged 

 segmented club, the seg- 

 ments of which may be 

 fixed, transverse teeth or 

 folded together so as to 

 open and close like the 

 leaves of a book. The tarsi 

 are five- jointed. Nearly all 

 of the adults of the famil- 

 iar types of the lamellicorn 

 leaf-chafers, cock chafers 

 and June beetles feed upon 

 vegetation and the larva?, 

 known as "white grubs," 

 live underground and feed 

 upon the roots of plants. 

 The scavenger beetles or 

 tumble bugs and dung beetles live upon dung and are of no economic 

 importance. A few other members, known as skin-beetles, feed upon 

 decaying animal skins, hoofs, etc. 



THE SOCIAL SCARAB^ID 



(Jocnonycha socialis Horn 

 (Fig. 230) 



Description. — The beetles are light brown with the prothorax and 

 head dark amber-brown. Some individuals are dark amber-brown 

 throughout. The average length is f inch and the width half as much. 



Life History.-— The life habits are unknown. In all probability the 

 larva 1 live in the ground and feed upon the roots of plants. The adults 

 appear in .April and often in sufficient numbers to destroy considerable 

 foliage. Their attacks are usually of short duration. 



Nature of Work. — The leaves or portions thereof are devoured by the 

 adults. 



Fig. 229. — White grubs, the larvae of beetles 

 belonging to the family Scarabceidas. Natural 

 size. (Original) 



