16 



drier g-round. Many of them, however, were still on the rushes 

 and on corn under water, apparently little disturbed by their sub- 

 mersion. 



Such of the second planting- of corn as had survived the bill- 

 bug- injury was in bad condition — dwarfed and much deformed in 

 growth. One field which had been planted the third time was al- 

 ready practically destroyed, and the bill-bugs were still present on 

 the corn. The crop on the field plowed in fall was in excellent 

 condition, but considerable damage had been done in some fields 

 which had been broken up from sod in the spring of 1901 and 

 plowed for corn again this spring. Their condition was evidently 

 due to insufficient cultivation last year, many rushes being left to 

 grow with the crop. This of course kept the bill-bugs in the fields 

 and enabled them to breed there last year. 



From the general condition of this region it is to be inferred 

 that fall plowing for two successive years with clean cultivation 

 of the crop will afford substantially'^ complete protection against 

 this bill-bug injury, except as the beetles from adjacent unbroken 

 g-round may occasionally enter a corn field iu search of food. 



Summary of the Life History. — Our earliest collections of this 

 beetle were made on the 21st of May, at which time the sexes were 

 seen in copula. It has been taken by us in swamps and corn fields 

 at many later dates up to July 27, although by the I7th of that 

 month it had practically disappeared from the corn. 



Eggs were found by us June 11, but as young larvae were pres- 

 ent at the same time oviposition must have begun as early as the 

 first of June. Indeed, Webster has found the eggs in Indiana late 

 in May.* Other eggs have occurred in the course of our work, 

 either in the field or in breeding experiments, July 4, 16, 17, 22, 23, 

 and 30, and also August 1, thus covering an interval of about two 

 months. 



The growth of the larvee seems to be rather slow, none of those 

 observed by us having reached full size before the 20th of July. 

 Other examples of the larval stage were found at intervals to Au- 

 gust 28; and in Webster's experiments, to August 30.* 



Pupie were taken from our breeding-cages September 10; and 

 in Webster's observations, from August 21 to 30. Imagos from our 

 September pupa: were observed September 16 and 17, and as our ex- 

 perimental work was done in the open air, the plants being protect- 

 ed only by wire screens, no acceleration of the transformations 

 could have taken place. Webster ('90) found adults, to- 



* Webster, F. M., 1890. 



