fields have furnished a sufliciciit basis for a hig-hly useful method 

 of prevention of the worst of these injuries, and this fact has made 

 desirable a new treatment of the subiect as a whole. 



Usual Conditions of Injukv to Cokn. 



While there is in Illinois a little g-eneral and unclassifiable in- 

 jury to corn by the bill-bug-s, by far the <^reater part of it occurs 

 under one of three conditions. If swamp lands are broken up from 

 g-rass in spring- and planted to corn the same year, and especially 

 if the common reed or the club- rush or other thick-stemmed g-rasses 

 with bulbous roots are common in the turf, the corn is extremely 

 likely to be badly injured if not wholl}' destroyed by one of the 

 swamp-loving- species of this g-roup. If such land is poorly culti- 

 vated, allowing- these bulb-root g-rasses to grow up again, the 

 injury may continue for at least another year. If an old timothy 

 sod, either pure or mixed with some other grass, is plowed in spring 

 and planted immediately to corn, this crop is likely to be severely 

 injured by other and smaller species than those which attack 

 the crop in swamps. I have known but one case of any consider- 

 able injury by these insects to a field of corn in Illinois except un- 

 der one of the above conditions. 



(1i<;ni':kai, Kkatuki':s oi' Lifi-; Histokv. 



The explanation of these facts is to be found in the life history 

 of the various species commonest in our region, and in the food and 

 feeding habits of the larva\ The largest of our bill-bugs breed 

 mainly and naturally in the bulbous roots of two or three large, 

 grass-like swamp plants, sedges, rushes, and the like. The ma- 

 jority of the species of medium size live chiefly in fields of tim- 

 othy, the larva' feeding on the root bulbs of that grass; and one 

 or two of the smallest species may feed either on timothy bulbs or 

 on roots of blue-grass in meadows, pastures, and lawns. 



So far as I know the bill-bugs pass the winter in the beetle 

 stage, in the ground, under rubbish, or in other protected situations, 

 and all whose life history has been at all closely observed in Illi- 

 nois make their appearance in spring, chiefly in fields in which they 

 have lived as larva- and where they have fed on the roots of grasses 

 the preceding year. 



As the adult beetles feed in nature on the same plants as their 

 larva' there is little to tempt them to migrate from one field to an- 

 other, and the facts lately collected in this state concerning the 

 previous history of badly injured fields clcarl)^ indicate that the 

 beetles pass the winter, as a rule, in the same fields in which they 



