398 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



The following conclusions may be drawn from the results obtained 

 in these experiments: 



(1) The percentage of corn-ear worm and mold injury decreases 

 as the number of dustings are increased. 



(2) The cost of dusting is prohibitive where corn is grown for grain 

 or forage but is practical where corn is raised for roasting ears, show 

 purposes, or for seed corn. 



(3) Sulphur is superior to flour or lime as a carrier for arsenate of 

 lead and there is some indication that it also serves as a fungicide. 



(4) Fifty per cent arsenate of lead does not control the corn-ear 

 worm as effectively as does 75 per cent arsenate of lead. 



A NEW SPECIES OF ISOSOMA ATTACKING 

 WHEAT IN UTAHi 



By R. W. DoANE, Stanford University 



During the past two summers, while carrying on certain investiga- 

 tions in Utah, for the American Smelting and Refining Co., Depart- 

 ment of Agricultural Investigations, I have had an opportunity to 

 study the life-history and habits of different wheat-infesting Isosoma, 

 and to note something of the effect of their work in the wheat fields. 



In the so-called dry farm regions in Salt Lake Valley it is a common 

 custom to plant wheat every other year, letting the fields lie fallow 

 during the alternate years. Often, however, the fields are not plowed 

 during the year that they are supposed to lie fallow, but are allowed to 

 grow a volunteer crop which is sometimes more or less profitable. 

 The plowing that is done at any time is usually with a disc plow and a 

 large part of the straw and stubble is left on the surface of the ground. 



It will at once be seen that such farm practices offer almost ideal 

 conditions for the development of stem-infesting wheat pests, and it 

 is not surprising to find the Isosomas doing an immense amount of in- 

 jury there, sometimes reducing the crop yield to a small proportion of 

 what it normally would be. 



My attention was first called to these pests when I found the adults 

 in considerable numbers in a field of winter wheat in May, 1914. 

 Two species were collected at this time. One proved to be the well 

 known wheat straw worm, Isosoma grande, the other species, as far 

 as I can determine, is undescribed. Because the larvse confine their 

 attacks to the leaf-sheath, I have called the species Isosoma vaginicolum, 



^Contribution from the Laboratories of the American Smelting and Eefining Co., 

 Department of Agricultural Investigations. 



