GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 45 



quickly defoliate plants attacked. When occuring on trees they 

 may be jarred off onto a sheet and killed with kerosene. Potatoes 

 well sprayed in summer with the standard bordeaux and paris green 

 solutions for fungus diseases and leaf eating insects will defy 

 attacks of blister beetles. In 1912 these insects were not so trouble- 

 some as in the preceding year. 



THE WHEAT STEM MAGGOT. 



From about July 6th to August 6th in 1912, an enormous num- 

 ber of letters were received expressing fear that the wheat crop 

 was seriously injured by some insect, farmers basing their belief 

 on the large number of "bald heads" noted in the grain fields. 

 While in some few instances, individual fields showed serious loss, 

 on the whole, the state probably lost on its grain crop only a very 

 small fraction of one percent on account of "bald heads." Field 

 workers reported these white heads to be most in evidence in the 

 counties of Ottertail, Redwood, Swift, Yellow Medicine, Chippewa, 

 Kandiyohi, Bigstone, Stevens, Traverse and Wilkins and com- 

 plaints were received from Caledonia, Stephen, Kennedy, Deer 

 River, Milaca, Northfield, Fargo, Windom, Perham, Osseo, Fari- 

 bault, Litchfield, New Ulm and a score of other localities. This 

 work was ascribed to the so-called "joint worm" by many, while a 

 few called it the work of the Hessian Fly. As a matter of fact 

 while the latter named insect caused a little loss possibly this year, 

 and a few specimens of the pupal stage of a joint worm were re- 

 ceived, these bald heads were due to the presence, in rather un- 

 usually large numbers, of the Wheat Stem Maggot, Meromyza 

 amei'ica7ia, and each year witnesses more or less of its work, though 

 as a rule it is not so much in evidence as it was in 1912. One need 

 not confuse the work of these three insects. In the first place the 

 Hessian Fly is never found hiside the steam, the maggot being con- 

 cealed beneath the sheathing leaf next the stem, and it is in this 

 position that the puparium or "flax seed" is found. The joint 

 worm larva on the other hand is found, in a gall-like growth, within 

 the stem. The slender greenish wheat stem maggot is found also 

 inside in stem, above the upper joint. The Hessian Fly maggot on 

 the other hand works just above one of the lower joints, for the 

 most part, and almost invariably causes the head to fall over and 

 rest upon the ground. 



