COPEOPHAGOUS BEETLES AND METHODS OF REARING THEM 



3 to 8 inches in length and 1 inch in diameter. Eggs have not been 

 found in the field. 



In the breeding boxes the egg chamber is always deeper in the soil 

 than the feeding tunnels. Dung is taken down into a cavity about 

 iy 2 to 2 inches in diameter and formed into a single, nearly perfect 

 sphere. The surface of the dung ball is then plastered with soil 

 to a thickness of nearly one-fourth inch except at one point, where 

 it is applied more thickly, giving the ball a pyriform appearance 

 (fig. 2). This coating of soil probably prevents excessive desicca- 



Figure 2. — Completed egg balls of Phanaeus triangularis in their individual chambers. 



tion of the larval food. The egg is laid in the smaller end of the 

 ball, just under the surface, in a small earthen cell or cavity. The 

 earthen cap is somewhat rounded and often contains a tiny hole. 

 The egg is not in contact with the manure, as in the Copris ball, 

 and when the egg hatches the larva digs its way into the interior 

 and feeds on the food provided by the parent. That this stocky, 

 clumsy beetle is able to build such a beautiful ball, construct the 

 smooth egg cavity, and cap it without crushing the fragile egg is 

 indeed marvelous. The egg balls are more nearly uniform in shape 

 and more symmetrical than are those of Copris. When the egg ball 

 is completed, the beetle leaves to construct another, and apparently 

 the progeny is forgotten. Several days are required to dig a burrow 

 and construct the egg housing. 



The egg is similar to that of Copris, but larger, the diameters be- 

 ing approximately 6 by 4.3 mm. It is elongate, subcylindrical, 

 and glistening white. The incubation period is from 6 to 9 days. 



Two females taken in the field and kept together in a box laid 

 34 eggs from May 20 to October 2, 1932. Unfortunately, the beetles 

 died during the extremely cold weather in February 1933. Egg de- 

 position would probably have continued into the following summer. 



