INJURIOUS INSECTS OF 1903. 11 



fields will afford a supply of this pest for the former. Since 

 this pest issues from the "flax seed" early in May, a stubble 

 field left for corn land and not plowed up to the loth of May 

 or later has probably discharged its quota of flies, ready for 

 mischief, before plowing. 



As stated elsewhere, this pest will increase and decrease at 

 regular intervals, due to the increase and decrease of its many 

 parasites, which in turn are due to the abundance or the contrary 

 of the fly. 



An assistant, Mr. Ruggles, visiting farms in the neighborhood 

 of Faribault, Rice county, on July 24th, at which place Chinch 

 Bug and Hessian Fly were both abundant, made the following 

 observation, viz. : That he could almost invariably tell where to 

 look for "flax seeds" from the fact that where the heads of 

 wheat were entirely shriveled the plant was badly infested 

 with Chinch Bugs, while plants with but few kernels whit- 

 ened almost invariably contained "flax seeds." This is inter- 

 esting and might be of some value to a farmer endeavoring 

 to estimate which pest was doing him the most harm before 

 the ripening of the grain. When the grain is about ripe and 

 afterward, the fallen heads tell the story. 



The food plants of the Hessian Fly are too well known to 

 need comment, viz., wheat, barley and rye. Assurances have 

 been made the Entomologist by a few farmers that "flax 

 seeds" have been found by themupon oats, but the most care- 

 ful search by this office has failed to reveal them, and we are 

 forced to conclude that these observers were mistaken, yet 

 there is no a priori reason why the traditional food habits of 

 this pest might not change in some sections, and oats be in- 

 cluded in their bill of fare. 



CHINCH BUG. 



While the extremely wet weather prevailing in some por- 

 tions of the state during last spring and summer kept this pest 

 in check in favored localities, other portions less wet or where 

 sandy soil and good drainage prevailed, suffered most seri- 

 ously. It was a banner year for Stearns and adjoining coun- 



