24 GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 



lowed b}^ the harrow. He claims that more real good results from 

 cultivation with a harrow, since that has a tendency to break up 

 the egg masses and expose the eggs to the effects of bleaching and 

 drying, and rendering them more easily accessible to their natural 

 enemies. He further claims that at the time the young hatch the 

 enveloping capsule has become soft and jelly-ilke, and that the 

 young grasshopper may easily push up through that toward the sur- 

 face in cases where the capsules are inverted by the plow. He does 

 not believe that the alternate freezing and thawing of the eggs 

 causes the death of the same, since, being close to the surface, they 

 may be subjected to that in Minnesota every season. In fact he ex- 

 posed to alternate freezing and thawing last winter newly hatched 

 grasshoppers, twenty, according to his report, having been frozen 

 and thawed twice with no mortality, except in the case of one indi- 

 vidual, which probably perished through rough handling. In spite 

 of his belief, as here cited, we still think that turning the eggs 

 under deeply must materially lessen the number of grasshoppers 

 which would naturally emerge the following season, and, plowing 

 being in accord with farm practice, shall continue to recommend it 

 until we know of something better. 



Since special attention was given by the field workers to practi- 

 cal method of control, and since our recomimendations are based 

 upon this practical work, it seems advisable at this point to quote 

 fully from the report submitted to this office detailing the work 

 done in the field in 1911 under Mr. Somes' direction: 



"The Hopperdozer, although widely known is so generally confused with 

 the "tar pans" of the early days and with various other more or less simi- 

 lar devices that a detailed description of the hopperdozer as used in Minne- 

 sota may be of some value here. We may say that we have found this "dozer", 

 when well designed and when used at the proper time of year, to be a cheap 

 and effective method of exterminating grasshoppers and woi-thy of more gen- 

 eral use. The essential part of a hopperdozer is a pan or trough of galvan- 

 ized or sheet iron, to the back and ends of which is fixed a light frame of wood 

 or iron extending vertically from 24 to 36 inches. This frame is to be covered 

 with cloth. The pan is mounted upon a wooden frame which is dragged upon 

 "skids" by two horses hitched to bars extending from the ends of the frame. 

 The pans, being made usually of galvanized iron, are commonly made sixteen 

 feet long, twenty inches wide and four inches deep since this size has proved 

 very handy to use and can be made economically and without waste of material. 

 On rough or hilly fields, however, we found it advisable to use pans eight feet 

 in length to better follow the rough surface. We have found it advisable to fix 

 several cross partitions of metal in the pan to lessen the waste from splashing 

 and to brace the pan. We have advised the use of cloth for the vertical wing 

 in preference to metal, largely because this material is less expensive and is 

 very considerably lighter, which latter factor is of considerable importance as 

 may be grasped when we recall the fact that the "dozer" is often to be dragged 

 through fields of young and growing grain. We may add further that a wing 

 of some soft cloth is in fact more effective than one of metal or even of oil- 

 cloth, although this may not be always apparent to the farmer. Our observa- 



