214 



THE NATIONAL GEOGRAPHIC MAGAZINE 



SOII, ABOUT PLANT ROOTS A COMMON MEANS OP ENTRY OP PESTS 



Moist earth such as comes about many plants has been the source of entry of a host 

 of our worst plant enemies, such as the Japanese beetle, the alfalfa weevil, and many others. 

 No method of disinfecting such earth with poisons is possible without killing the plants. 

 Moist earth is one of the best "gas masks," and many lives undoubtedly could have been 

 saved in France if the soldiers, before the gas masks had been devised, had filled their 

 handkerchiefs with moist soil and breathed through these at times of danger. 



The photograph is of Japanese iris roots, and in the surrounding soil are the grubs of a 

 pest unknown in the United States, related to the Japanese beetle. Needless to say, this 

 entire shipment was destroyed. 



entry of living plants from the United 

 States. These prohibitions, first based 

 on the grape phylloxera and later more 

 widely extended on account of the San 

 Jose scale, were usually absolute and 

 therefore much more drastic than the 

 ones now enforced under our own quar- 

 antine law. 



For example, no living plants from 

 America have for many years been per- 

 mitted to enter France, Germany, or 

 Holland, while similar or modified re- 

 strictions have been long enforced by 

 other European countries. 



A PROTECTIVE LAW FOR THE UNITED 



STATES 



The need for national quarantine legis- 

 lation for the protection of the farm, 



garden, and forest interests of this coun- 

 try from further invasions by foreign 

 pests was long appreciated, but the secur- 

 ing of this legislation necessitated an ex- 

 tended period of earnest effort. 



Toward the end of this period this leg- 

 islation was hastened by the increasing 

 numbers of gipsy and brown-tail moths 

 found during the years 1909-12 on im- 

 ported plants, and also by many other in- 

 sects and plant diseases and by the need, 

 which began to be generally appreciated, 

 of excluding such other important pests 

 as the Mediterranean fruit fly, the potato 

 wart, and the white pine blister rust. 



The movement was aided also by the 

 experience with the chestnut blight and 

 the San Jose scale. The entry of the 

 citrus canker, the Japanese beetle, and 



