THE SLENDER SEED-CORN GROUND-BEETLE. 19 



embedded in Dlack soil. In such situations it is rare to find Coleoptera except along 

 the edges, but here there were Clivinas (closely crowded) on a space not larger than 

 one's hand. 



REARING EXPERIMENTS. 



During the summer of 1906, when the writer's attention was first 

 called to this insect, attempts were made to rear it in confinement. 

 On June 15 several adults were collected and placed in a glass jar 

 that had been previously filled with rich soil, and corn planted 

 therein. No cover was placed on the jar, as the latter curved inward 

 near the top, rendering this precaution unnecessary. 



On August 18 the contents of the jar were carefully examined, but 

 no eggs or larva? could be found. There were 1 1 adults — not as many, 

 however, as were placed in the jar on June 15. They had tunneled 

 throughout the soil, but the corn had not been attacked. The beetles 

 were still in good condition in December, though no eggs or larvae 

 could be found in the jar. Whether artificial conditions tend to 

 prolong their lives or whether this is the average length of life could 

 not be ascertained. 



October 4, 1906, in a field near Richmond, Ind., a tight box 32 by 8 

 by 10 inches was let down vertically into the soil, a long box filled 

 with sifted soil being used, so the beetles could go below the frost line 

 if necessary. Some oats, corn, and wheat were planted in this box 

 and about 24 adult beetles were placed inside, after which the box 

 was covered with a closely woven wire screen. They began burrowing 

 into the soil at once, very much after the manner of moles, parting 

 and pushing aside the earth with their strong fore legs. On October 

 8, 42 more beetles were placed in the box. On June 5, 1907, this box 

 was examined and one adult beetle was found near the top of the cage, 

 just below the surface of the soil. Several others were found at and 

 near the bottom, in their burrows, with their abdomens distended as 

 if containing eggs. These last were apparently dead, though the 

 tissues seemed to be in good condition, but some of them on being 

 dissected were found to contain numbers of a little mite, determined by 

 Mr. Nathan Banks as Canestrinia sp. No eggs, larva?, or pupse could 

 be found. The fact that comparatively few beetles were present is 

 probably due to their cannibalistic habits and to the presence of the 

 mites, it being since learned that the beetles will devour each other 

 when closely confined or where there is an insufficient food supply. 



During the summer attempts were made to rear them in boxes 

 containing soil from the fields where they had been found injuring 

 corn, mixed with decaying wood and growing plants of different 

 kinds, but without success. 



In November a box 8 feet long, 3 feet deep, and 2 feet wide, made 

 of tongue-and-grooved boards, was settled in the ground until the 

 top was even with the surface. This was done on the farm of Mr. 

 William G. Baker, near New Paris, Ohio. The box was then filled 



