HESSIAN FLY. 87 



The fire as it spreads draws towards the middle of the field, 

 and, however the wind may drive, the flames cannot return 

 over the already charred surface.* 



Treatment of infested straw after threshing. — In regard to 

 infested straw taken off the field, it has been found to 

 answer well to stack this carefully after threshing, well built 

 up square and firm, like a haystack, instead of throwing it 

 anyhow ; thus a very great proportion of the flies which come 

 out of the "flax-seeds" are destroyed, simply because they 

 are not able to get to the outside of the stack. 



The kinds of Corn attacked are Wheat, Barley, and Eye. 

 Oats are not known to be attacked, neither are any of the 

 crops know^n as roots, such as Turnips, Mangolds, Potatoes, 

 &c. ; nor Pulse, as Peas, Beans, &c. ; nor Cabbage, Flax, 

 Mustard, or ground or bush fruit-trees. Flotation of crop 

 with most of these would both ensure safety from the pest to 

 the crop itself, and also, by removing the food necessary to 

 the insect, would give a thorough check to its presence so far 

 as that crop was concerned. 



Two kinds of wild Grasses subject to attack of Hessian Fly 

 are "Timothy Grass" {Phleum pratense) and "Couch Grass" 

 {Triticum repens). 



In 1887 the first-named of these was found to be severely 

 attacked in the Russian Government of Tambov, and Couch 

 Grass was attacked in the government of Tambov, and also 

 of Woronetz ; "Couch Grass was so severely attacked that 

 in whole districts covered with this Grass it was destroyed." 



There has been doubt and difference of opinion as to other 

 kinds of wild Grasses which may be liable to infestation, but 

 the above observations give an additional reason for skimming 

 and dragging rubbish together and burning it in the fields, 

 and also for preventing neglected Grass or hedge-banks by 

 Corn-land being allowed to become nurseries of the Hessian 

 Fly. 



A firm, stiff-strawed kind of Wheat or Barley, and such 

 cultivation of the land and choice of soil, and also exposure, 

 as will give a vigorous and healthy growth, are the best 

 means of reducing amount of damage to be expected if attack 

 comes. 



The stiff straw does not elbow down readily under mode- 

 rate infestation, and where there is healthy growth the plants 

 will stand an amount of loss of sap from maggot-suction 

 which would have ruined them if weaker. A crop of Barley 

 grown on a dry hot exposure may be seen going down under 



* For the above hints I am indebted to Prof. Hoyes Pantou, of the Agricul- 

 tural College, Guelph, Canada. 



