10 



thrown up by the early cultivations. The beetles cut a horizontal 

 burrow into the growing stalk until they reach the center, the center 

 roll of leaves usually being cut through. The coarser fibers of the 

 outer sheaths are shredded away with the mandibles and front tarsi, 

 the latter being used more especially to pull away the stringy fibers 

 after they have been cut loose at one end. As soon as the hole is 

 large enough for the head and a portion of the thorax, the beetle 

 uses the middle legs as braces while it cuts its way deeper into the 

 stalk (fig. 1).' Some instances were noticed where small and tender 

 shoots had been entirely cut through and in a few cases shoots that 

 stood against a larger stalk had been cut through, the beetle 'continu- 

 ing its work into the next stalk. 

 The beetles seemed indifferent to 

 the size of the stalk attacked, 

 larger older shoots being injured 

 as often as the small tender ones, 

 even when growing in the same 

 clump of cane. The effect on the 

 shoots is very different from that 

 on the older stalks, the latter 

 sometimes recovering from the 

 injury if not too severe, while the 

 former soon wilt, the center 

 leaves dying first. On account 

 of the beetles' habit of working 

 underground it was found very 

 difficult to determine the length 

 of time necessary to cut a hole to 

 the center of the stalk. One 

 beetle was seen to enter the 

 ground, and twenty minutes later 

 it had reached the center of a 

 a stalk three-fourths of an inch 

 in diameter, as was readily de- 

 termined by pulling out the cen- 

 tral core of leaves. At times stalks containing several partially 

 completed and one complete burrow are to be found. Usually but 

 one cutting is made on a stalk, and, if this reaches through the cen- 

 tral core of rolled leaves, the shoot quickly dries up and in a few 

 days falls to the ground. When examined, the point at which the 

 cutting was made now appears decayed, and in and on the rolled 

 leaves in the interior may often be found small dipterous larvae feed- 

 ing on the fermenting and decaying cane or corn. 



Corn is attacked in the same manner as cane (fig. 2), but the injury 

 is usually closer to the base of the stalk and more disastrous in its 



Fig. 2. —Ligyrusrugiceps: corn showing injury 

 (after Comstocli). 



