234 HOUSEHOLD INSECTS 



the burrows. We show in Fig. 69 a section of the side 

 of a bin showing the burrows made by the larvae. 



Slingerland made observations on the life history and 

 habits of the beetles for a period of nearly a year in which 

 he kept them in the insectary. He placed the beetles in 

 tumblers containing wheat. Here the beetles freely laid 

 their eggs, which hatched and the larvae came to maturity, 

 using the wheat grains as food. We have also found them 



in oatmeal and kept 

 them under observa- 

 tion for a long in- 

 terval in this cereal. 



Fig. 69. — Section of bin showing holes in the Thp p^p- jc q small 

 wood made by the larva of the Cadelle. g ®^ ' 



white object, much 

 longer than wide and slightly curved. It would take 

 nearly 20 of them, placed end to end, to reach one 

 inch (1.3 mm. long and .3 mm. wide). Eggs laid about 

 August 5th hatched August 15th, thus indicating an 

 incubation period of about ten days. The newly 

 hatched larvae are very small and resemble the full- 

 grown ones in color and general appearance. The larva? 

 that hatched from the eggs in August grew slowly and 

 lived in the warm insectary among the wheat grains 

 until the following April and May. In the latter part of 

 April one larva was found in a burrow in a pine stick that 

 had been placed in the tumbler. Later it pupated in its 

 burrow. About the middle of May another larva was 

 found in its burrow in a pine stick. A month later this 

 larva had changed to a pupa and on July 10th one of these 

 pupae had changed to an adult beetle, while the other had 

 dried up and died. Thus it evidently takes about one 

 year for the insect to pass through its life cycle. 



