6 CIRCULAR 3 51, U. S. DEPARTMENT OF AGRICULTURE 



A group of reared specimens which emerged in May and June 1933 

 did not commence oviposition until September. 



For a study of the immature stages the egg balls were placed 

 singly on slightly moistened sand in pint mason jars capped with 

 solid^ tops. Of 24 specimens that were reared, IS were females. 

 There seems to be not more than one generation a year. The aver- 

 age period from egg hatching to adult emergence was 344 days. 

 with a minimum of 269 and a maximum of 391 days. The eggs de- 

 posited in September produced adults only a few days later than 

 those laid in May. The pupal period ranged from 37 to 50 days. 

 Three larval instars were found, and the data are shown in table 

 1. When the larva was a few weeks old. the inner ball of dung 

 had shrunk and the surrounding husk of soil was easily broken. 

 The fully developed larva constructed a spherical, creamy-white 

 cell inside the ball. 



When the ball was opened slightly, the larva ejected into the hole 

 an anal paste which, when dry. formed a hard, cementlike plug. 

 This process of repair has been observed with other species of dung 

 beetles. 



An interesting observation pertaining to feeding habits was made 

 of a male of Phanaews triangularis in a breeding box January 29, 

 1933. The insect was feeding at the margin of a patch of dung, and 

 several observations daily showed a continuous consumption of food 

 and a constant ejection of feces until a string several feet long had 

 accumulated. Approximately 2 cubic niches of dung was consumed 

 in 7 days. 



CANTHON LAEVIS (Drury) 



This species is widely distributed, and its actions in carving out and 

 rolling away balls of dung are frequently observed. At times, par- 

 ticularly after rains, two dozen or more beetles may be seen cutting up 

 a dropping, and sometimes the entire dung patch is destroyed. In 

 hot. dry weather 50 to 100 beetles may be found milling around inside 

 a dropping. One unusually large dropping was estimated to contain 

 600 beetles. The insects probably congregate in this manner for 

 feeding and protection until they are ready to prepare for their 

 progeny. 



Canthon laevis females roll away and bury balls of dung for food 

 and for egg deposition. The greatest activity is in the spring, and 

 very little rolling has been observed in the fall. When it has rolled 

 a ball about for an hour or more and found a place for burial, the 

 beetle begins to dig under and around the sphere until it gradually 

 disappears into the hole. Upon excavation a few days later the 

 beetle's exit tunnel is found extending down to a depth of 2 to 5 

 inches, where the ball is lying in a neat spherical cavity : or. if the 

 dung ball is used for adult food, the beetle may be found feeding on 

 the manure and the material reduced to shreds. In either case the 

 ball is from five-eighths to nearly 1 inch in diameter, including the 

 coating of soil which has been accumulated in the rolling process. 

 In her underground^ chamber the female apparently finishes the ball 

 by applying an additional coating of soil at some point for the egg 

 cavity or cell, making it pyrif ornTin shape. 



