INSECTS INJURIOUS TO SWEET CORN I97 



was often stunted and twisted, and the lower leaves were in- 

 variably brown and withered." 



From examination of numbers of stalks it is evident that eggs 

 are laid in them near the soil surface, and the young larvse 

 usually work downwards. The presence of larvae in the stalks 

 proper is apparently only after the roots and the pith below 

 ground have been exhausted. The beetle (fig. 125, c,d) is black, 

 and has the thorax marked with three raised lines. The length 

 is about half an inch exclusive of the snout, which measures 

 about one-sixth of an inch. The larva is of about the same 



Fig. 125.— The Southern corn bill-bug. a. Larva; b, pupa; c, beetle, from above; a, 

 same from side. AH slightly enlarged. (From Riley, U. S. Dept. Agr.) 



length as the beetle, nearly white, of the peculiar curved form 

 shown at a, the head being a little darker and the mouth-parts 

 still darker. 



The Northern Corn Bill-bug {Sphenoplionis zccc Walsh) is 

 somewhat restricted to the north as regards injuries. The adults 

 alone injure corn, the larvae subsisting on the roots and bulbs of 

 timothy and other grasses. In 1891 the writer investigated an 

 invasion of this species in Chester County, Pennsylvania, where 

 the beetles were attacking newly-planted corn just beneath the 

 surface. As was surmised before visiting this point, a stream 

 of water was running close at hand in the marshy soil where 

 rank vegetation grew in profusion, including different forms 

 of sedges, rushes, weeds and wild grasses, the obvious original 

 starting place of the insect. The principal damage was done to 

 cornfields located from fifty to one hundred feet above the creek 



