bilities of poultry in the control of many highly injurious tim- 

 ber insects, including the gipsy and brown tail moth of New 

 England. 



There is another class of insects affecting cereal and forage 

 crops made up of sucking insects. Of these the spring grain 

 aphis is a good representative. It is now well understood that 

 if nothing is done in the southern-most points where this pest 

 starts in the spring, it does its greatest damage by producing 

 there a progeny that spreads in vast numbers to the North. 

 As was pointed out by me in detail in my Circular No. 144, 

 pp. 12 and 13, the Bureau has nothing in the way of direct con- 

 trol other, than plowing infested patches of fields under 

 spreading straw over the patches affecteed and burning it, or 

 use a 10 per cent kerosene emulsion that kills admittedly only 

 about 50 per cent, according to the Bureau's claims, at a cost, 

 years ago, of $4.00 per acre. None of these means of control is 

 satisfactory. 



I had shown as far back as 21 years ago that for sucking 

 insects there is nothing more feasible as a means ot control 

 than the use of heat by a gasoline torch, and in my Circulars 

 No. 140, 141, 147 and subsequent Circulars how torch outfits 

 might be constructed that furnish a blast for sucking insects 

 on any kind of vegetation. In the case of the grain aphis, for 

 instance, some such wheeled frame as that of a hayrake could 

 be fitted with a tank holding gasoline and having any desired 

 number of leads to blow a hot air blast through the grain 

 plants. An automobile truck is better. Morevover, I pointed 

 out as far as 21 years ago that such a blast also destroys the 

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