APPENDIX 



INJURIOUS INSECTS, AND MODES OF DEALING WITH 



THEM 



( For reference. ) 

 FARM PRACTICES. CULTURE 



Whenever an insect appears in injurious numbers 

 it becomes highly essential that a knowledge of its 

 life history should be acquired. In the life of many 

 insects there is a stage where methods of culture or 

 farm practices will destroy the insects and prevent the 

 possibility of damage from them or from their direct 

 offspring. As illustrations, in alfalfa-growing regions, 

 native grasshoppers lay their eggs in the alfalfa-field 

 late in the fall of the year. These eggs hatch in the 

 early spring and the young defoliate the alfalfa. They 

 mature during the summer and lay eggs on the same 

 ground. These will destroy the next year's alfalfa 

 yield. If the alfalfa lands are thoroughly harrowed 

 in the early spring with a disk hamnv, the egg-pods 

 are turned out of the ground and become a prey to birds 

 and other insects. The exposure to sun and rain and 

 the sudden changes in temperature destroy any which 

 escape the birds and insects. The disking, likewise, 

 materially increases the alfalfa yield. 



The Hessian fly seems to have but one vulnerable 

 point in its life; that is the time from wheat harvest 

 until wheat sowing. The females of the earl}' fall 

 brood seem to be so timed that they lay all their eggs 



(301) 



