37 



12th October. During all this time no imagos could be got by wide- 

 spread and diligent sweeping. On the 14th of that month, how- 

 ever, no larvae occurred in the experimental plots, but a single 

 imago was taken in the one at Edgewood. Again, on the 27th 

 October, an imago occurred in our collection at Champaign. On the 

 31st October, 1884, half-grown larvae were found in rye; on the 2d 

 November a siugle larva occurred in wheat at Billett Station; and on 

 the 16th November full grown larvae were obtained at Edgewood. The 

 passage from the second to the third brood of this species occurs, 

 consequently, in October. 



To these data I will only add the following record of times and 

 places of occurrence of tlie imago of the third brood. This was- 

 taken in wheat at Danville on the 20th May; at Urbana on the 

 21st; at West Union, in Clark county, on the 24th; at Mt. Carmel 

 on the 28th; at Anna on the 6th June; and at Champaign eTune 

 18, at which latter date the larvae of the following generation were 

 also already to be detected in the part of the stalk just above- 

 the upper node. 



Besides my own contributions, we have a series of observations 

 made by Mr. F. M. Webster, an assistant to the Entomologist of 

 the United States Departmei)t of Agriculture, published partly in 

 1885* and partly October lO, 1886.t These observations, made in the 

 same latitude as my own, confirm the interpretation of the facts 

 here given and extend somewhat the periods of the different 

 stages of the insect. They are incorporated in the calendar on 

 another page, but need not be separately discussed. 



Prof. A. J. Cook, of Michigan, reported in the "Prairie Farmer" 

 for August 21, 1886, the frequent occurrence of the w^heat bulb 

 worjQ in the stems of oats, upon which it produced, of course, 

 the same effect as upon wheat and rye. He also suggests the 

 possibility of its working in autumn in volunteer oats. 



These data may be generalized in the following summary ac- 

 count of the life history of the species. The eggs of the first 

 brood are laid in May and June, the generation of larvae result- 

 ing continuing into July, but commencing to pupate in June, and 

 first reaching the imago stage early in July. These imagos 

 doubtless live until August, during the early part of which month 

 the eggs are laid for the second brood. The larvae of this brood 

 may be found in August, September, and October, transformations 

 probably commencing during the latter part of August. Certainly 

 imagos occur during September and October; and the eggs for 

 the third or winter brood are laid in September, so far as observed. 

 The larvae resulting from these eggs in October and November, 

 hibernate without transformation and continue until the middle 



*Rep. Com. Aj^r. for 1884, p. 389. 



tPurdae Univ., School of Agr., Bull. No. 9, p. 5. 



