12 



canadensis, fig. 1), the stems of which literally swarmed with the larvfe 

 of thi.s species. It beyond question would have furnished enough 

 adults to have stocked hundreds of acres of barley had it been within 

 reach. The presence of the old stems clearly indicated that the place 

 had been neglected for years, and grass stems of the previous year 

 were tilled with punctures where the adults had made their escape. 

 Without anyone knowing it, there was here kept a perpetual nursery 

 for barley straw-worm flies, and though not at present a barley coun- 

 tr}^, it is true, it is easy to see what the effects would be were the sit- 

 uation otherwise and must be elsewhere where this grain is more 

 largely grown. 

 The locality from which I secured the least number of these insects, 

 and, in fact, none of the grain-attacking species 

 at all, is located along the same railway, in the 

 edge of the village of Peotone, 111. Here the 

 topography of the ground along the railway is 

 even worse than that in the Champaign locality, 

 but close proximit}' to the village rendered more 

 attention to it necessary. I am informed b}?^ 

 those living near the place that it is regularly 

 mown off during the latter part of June and 

 again in September. The material used in my 

 breeding experiments was collected August 12 

 at Champaign and August 21 at Peotone, and, 

 though the Canadian rye grass was much more 

 abundant in the latter locality, and to all out- 

 ward appearances at the time the material was 

 secured offered the joint-worms a far superior 

 place to develop there, yet with ample material 

 I did not obtain a single individual, though in 

 Dekalb Count}^, about 60 miles west of Chicago, 

 where, to my certain knowledge, no wheat or 

 barley has been sown for years, from grass col- 

 (Eiymus canadensis), (after lected August 20 I reared quite a number of 

 seribner). thcsc iusccts. The Dekalb Count}^ material was 



collected from along the neglected roadsides in the country. I can 

 see no possible explanation of the difference in abundance of the joint- 

 worms in the r3^e grass secured at Champaign and that secured at 

 Peotone, except the difference in the attention given to mowing off' 

 the grass during the summer — the same attention that farmers can 

 without trouble give to the roadsides, fence corners, and ditch bor- 

 ders on and about their own premises. These things are a part of 

 good husbandry, yet among intelligent farmers I have found the two 

 species of rye grass growing not only by the roadsides, but along the 

 very borders of their wheat fields, in some cases the grass and wheat 

 being intermixed along the extreme edges of the fields of grain. 



Fig. 1.— Canadian rye grass 



