13 



yellow. It is generally less abundant than some of the others, but 



sometimes individuals are quite numerous. Besides these, several 



undescribed species have been 



recorded from the northwestern V ^v ./ J 



part of the country. The infiu- 



W'J 



lo^triiftnr. iiiucii oiilarged (from 

 Riley). 



ence of these minute parasites in \^-.-:"v 

 regulating- the world's wheat sup- 

 ply is not at all understood, and it 

 is doubtful if wheat could be suc- 

 cessfully raised were they all to be 

 suddenl}' swept out of existence. 



REMEDIAL AND PREVENTIVE 



MEASURES. Fig. U.-Mn-hi,.-: 



Of remedies there is little to be 

 said, since after the pest becomes established in a lield it can not be 



reached by any measure likely 

 to destroy it. The application 

 broadcast of some quick-acting 

 fertilizer containing a large 

 percentage of phosphate, made 

 as soon as general infestation 

 is apparent (see fig. 10), will 

 cause the plants to tiller more 

 freeh' and give them sufficient 

 vigor to withstand the winter, 

 and thus increase the number 



Fig. lb.-Plat!/ga>^kr hcrrickil, much enlarged (from of healthy stcmS the followdug 



^^^^y)- spring. Any other means that 



could be employed having a similar effect would be a remedial measure. 



All practical measures must necessarily be 

 in the nature of preventives, looking (1) to the 

 elimination of the pest in the young wheat in 

 the fall, and (2) to the increasing of the vigor 

 of the young plants in order to enable them 

 to counteract the insect's effect, wdien present. 

 Under the first come late sowing, rotation of 

 crops, burning of the old stubble, and the de- 

 .struction of volunteer wheat. Under the sec- 

 ond should be classed the enrichment of the 

 soil, its thorough preparation, and selecting 

 and properly sowing the best seed. 



LATE SOWING. 



By late sowdng as here recommended is meant 

 moderately late sowing of fall wheat in any 

 locality, for extremely late sowing, which has 

 sometimes been advised, would be even worse than early sowing. The 

 later appearance of the fly in the fall, as we pass from the north south- 



FlG. 16. — Bwutomus subaptcruSy 

 much enlarged (from Kiley). 



