February, '13] presidential address 131 



numbers to form destructive pests. Usually the damage done by them 

 to their old food plants has been greater than that which ordinarily 

 took place in the country from which they both came, and has con- 

 tinued to be so until their predaceous and parasitic foes have become 

 sufficiently numerous, or native forms have learned how to use the 

 pest or both. Not only have the injurious species imported with 

 specific plants attacked these plants; but in some instances they have 

 found native plants to their liking. Incidental to the importation of 

 plants, species of injurious insects and fungous diseases not in any way 

 injurious to the specific plants with which they came have been brought 

 in. Some species coming to us in this way have proven very injurious 

 to other species of useful plants. 



If this process of distribution be allowed to go on it seems entirely 

 probable that every injurious insect and every fungous disease will 

 become as widely distributed throughout the earth as the climate 

 will permit, because man has removed the physical- feature barrier. 



It is the business of the inspection service to discover the injurious 

 forms that are thus being distributed and to take such measures as will 

 prove a barrier to their further spread. This duty the service has well 

 understood and has tried to fulfill. Unfortunately, with very few 

 exceptions, all efforts toward stopping the distribution of serious insect 

 pests and plant diseases have resulted, or promise to result, merely in 

 delaying the spread of the organism. This result has, of course, been 

 due to a variety of causes; but chiefly to the fact that natural forces 

 operate for twenty-four hours every day in the year and everj^ year in 

 the century, while horticultural inspection operates only intermittently. 

 In the light of past experience, it seems probable that the distribution 

 of every injurious insect and every plant disease will coincide with that 

 of its food plants in so far as climate will permit, and that all the horti- 

 cultural inspection service will be able to do will be to delay the distri- 

 bution of dangerous species until their normal environment of enemies 

 can be developed and efficient artificial measures for their control 

 discovered. It is well to recognize our limitations and not allow our- 

 selves in the heat of argument before committees on appropriations to 

 promise eradication if only enough of the "sinews of war" is put into 

 our hands. 



Whether the inspector will or no, the general public and the fruit 

 grower look upon his certificate as a guarantee of freedom from injur- 

 ious insects and plant diseases. It seems likely that the time is not 

 far distant when in his full capacity of nursery, fruit planting and fruit 

 inspector, the official horticultural inspector will be held responsible 

 by the public for the sort of fruit with which it is fed. Your present 

 chairman is in entire sympathy with the contention of our ex-president 



