spores of fungi that may be on a plant. This use of a blast thus 

 offers the only feasible means to attack fungus diseases on a 

 growing grain and forage crop. The Bureau of Plant Industry 

 was wanted all along to investigate this. 



I had shown in my Circular No. 14? how these same fit- 

 tings could be used to help make up an outfit applying a hot 

 air blast too tall trees. Thus, for instance, we now have the for 

 pearthrips seriously threatening the orchard industry. The 

 use of a hot air blast is moreover not only feasible against the 

 adults of the pearthrips as they appear at the blooming time, 

 but also for the destruction of the larvae several weeks later. 

 These, by being given a slight licking, drop to the ground, 

 where a licking at close range kills them. This matter is fully 

 explained in my Circular No. 147, pp. 8 to 13. 



However, during the past 30 years certain other sucking 

 insects have come into prominence as plant pests in general 

 and fruit-and seed pests in particular. The most important 

 of these are found in the group of bugs known as stink bugs." 

 Their increase in damage is traceable to bringing large tracts 

 of pasture lands under cultivation, with the consequent in- 

 crease in succulent food supply and the incident curtailment 

 of the breeding places of birds, probably the most important 

 natural enemies of theirs. Of these bugs only two have thus 

 far done great damage, while others may do so at any time if 

 not checked by suitable means of control. 



The two bugs in question are the Mexican conchuela 

 (Pentatoma ligata) and the grain bug (Pentatoma) Chloroch- 

 roa sayi). The first of these, with reference made to the grain 



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