Entomology and Other Sciences 293 



their depredations. The early efforts in protecting crops by use of so- 

 called insecticides, consisted largely in treatments with soot, ashes, 

 lime and a host of other materials. Some of the earlier recommendations 

 included as many as six or a dozen ingredients. A typical formula 

 recommended in 1779, for mealy bugs, was: 



Sulphur 8 ounces 



Scotch snuff 8 ounces 



Hellebore powder 6 ounces 



Nux vomica 6 ounces 



Soft soap 6 ounces 



Cayenne pepper 1 ounce 



Tobacco liquor 1 quart 



Water, boiling 1 gallon 



The author of this recipe was evidently not entirely confident of 

 is effectiveness for he recommends that the plants be washed with the 

 decoction and that the insects be removed while washing. 



The real advances in insecticides have been the result of specific 

 insect problems. The Colorado potato beetle and cotton worm brought 

 about the introduction and use of Paris green. The development of 

 arsenate of lead was the result of problems connected with the gypsy 

 and browntail moths. The seriousness of the San Jose scale brought 

 about the development of the miscible oils and lime-sulphur. Other 

 needs have had an influence on the development of insecticides. Thus 

 the need of standardized tobacco extracts has resulted in the manu- 

 facture of standard strengths and made available the practical use 

 of this most valuable insecticide. Similarly the poison gases, used dur- 

 ing the war, have opened our eyes to their possible utilization. 



There is a vast field for the properly fitted chemist for the de- 

 velopment of new insecticides and new phases of present day insecticides. 

 There is likewise a large field for the engineer, for the application of 

 insecticides is itself as important a problem as the preparation of in- 

 secticides. 



We spoke of the relation of entomology, and particualarly economic 

 entomology, to the other branches of science. As Dr. S. A. Forbes has 

 said: "It is when we search for specific reasons for our successes here 

 and our failures there that we are driven to a scrutiny and analysis 

 of controlling conditions of every description, and so find ourselves in- 

 volved in studies so far outside entomology, commonly so-called, that 

 we are obliged to apply for assistance to the physiologist, and the 

 chemist, and the physicist, and the meteorologist, and the geographer, 

 and the agriculturist, and the animal husbandman, and the bacteriologist, 

 and the physician, and the sanitarian, or in a word, to the ecologist, 

 who from the nature of his studies, must, if he is to thoroughly cover 

 his field, be something of each and all of these and still something more." 

 As is true with every other science the field of entomology is broader 

 than is generally supposed. In the study of insecticides the entomologist 

 must have a thorough knowledge of the science or the assistance of the 

 chemist, the plant physiologist, the horticulturist, and the meteorologist 

 and in development of means of application the services of the engineer 



