18 BULLETIN 251, U. S. DEPARTMENT OF AGRICULTURE. 



below the surface of the earth. It appeared dead, but on removal 

 soon revived. 



At the end of 48 hours another cage was examined, and a live beetle 

 found 3^ inches below the surface of the earth. This cage was 

 replaced and on the following morning, after it had been submerged 

 for 2^ days, the beetle was found on the surface of the water. 



The last cage was opened at the end of four days, and an active 

 female was found in the earth, which was now very compact. The 

 beetle was replaced in the mud and the cage submerged, but at 

 3.10 p. m. it came to the surface of the water, after having remained 

 beneath it four days and two hours. 



These experiments indicate that this species is able to withstand 

 excessive amounts of moisture and that in the spring, when lowlands 

 are flooded, the majority of the insects will survive, apparently with- 

 out serious inconvenience. 



On March 21 a female Calosoma beetle that had been submerged 

 for four days and two hours was placed in a tub of water and floated 

 about on the surface. It seemed desirable to ascertain how long the 

 insect would remain alive and float when the temperature of the 

 water was maintained at about 39° F., and also whether it was able 

 to make any progress in swimming. During the first hour and fifteen 

 minutes the insect swam a distance of 22 inches. It rested on the 

 water very easily, less than one-half of the body being submerged. 

 The legs moved continually, but its progress was very slow. This 

 beetle remained in the tub of water 15 days and at the end of that 

 period was removed for dead. In a few hours it revived and began 

 feeding, and was used later in the summer in- rearing experiments. 

 This shows that in the spring beetles of this species might survive 

 several days if they should fall into ponds, and that they would 

 probably float with the current and might be distributed quite a 

 long distance in this way, especially if they fell into streams or 

 rivers. 



NATURAL ENEMIES. 



It is undoubtedly true that this species is eaten to some extent 

 by birds, and the hairy woodpecker has been charged with destroy- 

 ing it on several occasions. The crow has been observed to feed on 

 the beetles and also to carry them to their nests which were occupied 

 by young birds. Among the other vertebrate enemies may be men- 

 tioned skunks, raccoons, and foxes. The last two mentioned, when 

 kept in captivity, will feed on these beetles very freely. Abundant 

 evidence has been secured that skunks destroy large numbers of the 

 beetles. In some sections where these insects were very abundant it 

 was found that the remains of the beetles formed the chief con- 

 stituent of the excrement of this animal. (PI. VII.) Not only 

 do the skunks secure beetles which may be on the ground, but they 



