February, 1912.] 



129 



Plant Sanitation. 



infested stock was carried into twenty- 

 two States, covering the country from 

 the Atlantic seaboard to the Rock 

 Mountains. During the first of these 

 years no fewer than 7,000 winters-nests 

 of the brown-tail moth, containing 

 approximately 3,000,000 larvae, were 

 found in shipments into New York State 

 alone -seed material enough to infest the 

 whole United State within a few years. 

 During the second of these years 617 of 

 these nests were found on nursery stock 

 shipped into the State of Ohio, and a 

 much larger nuoaber, approximately the 

 same as the year previous, were again 

 sent into New York. Smaller numbers 

 of these nests, proportioned to the 

 amount of nursery stock received, were 

 sent into other States east of the Rocky 

 Mountains during both these years. 

 Fewer brown-tail moth nests were 

 received during the season just ended 

 (1910-11), owing to the agitation in this 

 country and more strict supervision by 

 foreign Governments. 



So far as possible, this stock, as 

 voluntarily reported by customs officers 

 and railroads, has been examined and 

 the brown-tail nests removed or des- 

 troyed by State authorities, or, where 

 these were not available, by agents of 

 the Bureau of Entomology of the United 

 States Department of Agriculture. 

 Undoubtedly many shipments have not 

 been reported or examined, and it is 

 quite probable that local infestation has 

 already started at different interior 

 points. The history of both the gipsy 

 and brown-tail moths in New England 

 shows that these insects may be pre- 

 sent for several years without being 

 noticed, slowly again headway, and then 

 suddenly develop their full power of 

 destructiveness. 



It is scarcely necessary to comment on 

 the danger from the careless introduc- 

 tion and wide distribution of these two 

 orchard and forest pests. In a limited 

 district in New England more than a 

 million dollars a year have been spent 

 for a long period in a mere effort 

 to control these two insects, aud the 

 General Government is now appropriat- 

 ing three hundred thousand dollars 

 annually to endeavour to clear them 

 from the border of main nigh ways 

 and thus check their spread. These 

 expenditures do not take into account 

 the actual damage done, but they 

 do serve as a measure of the danger 

 to the whole country from the recent 

 distribution of these two insects on 

 imported nursery stock. 



As further illustrations of the constant 

 risk from lack of legislation may be 

 mentioned two very recently introduced 

 17 



insects which will undoubtedly prove 

 very expensive pests in future years. 

 The European alfalfa leaf-weevil, on the 

 authority of the entomologist of the 

 Utah Experiment Station, Mr. Titus, was 

 probably brought into Utah on pack- 

 ing of nursery stock or other merch- 

 andise from Europe. This leaf-weevil 

 has already destroyed much of the 

 value of the important alfalfa crop 

 of Utah, and is spreading into adjacent 

 States. The other illustration is the 

 Oriental cotton scale (Pulvinaria psidii), 

 probably the worst scale pest of citrus 

 and other subtropical plants in Southern 

 Asia. This scale insect has recently 

 been introduced into Florida on im- 

 ported stock, and is already well esta- 

 blished there. 



New plant diseases, against the en- 

 trance of which there is at present no 

 bar, may even more seriously jeopardise 

 the farm, orchard and forest products 

 of this country. Imported potatoes from 

 Newfoundland are now bringing in the 

 potato wart disease, which wherever it 

 has been introduced in Europe, and also 

 in Newfoundland, puts a stop to potato 

 culture. The importation of white-pine 

 seedlings is now bringing in the European 

 white-pine blister rust, which, if estab- 

 lished and disseminated, will destroy 

 much of the value of our white-pine 

 forests. Absolute quarantine against 

 these two plant diseases is the only 

 means of keeping them out. The chest- 

 nut disease, now practically shown to 

 have been introduced on trees imported 

 from Japan, illustrates what may 

 quickly happen from such unchecked 

 introductions. 



More than half of the important insect 

 enemies and plant diseases now estab- 

 lished in the United States have been 

 brought in on imported nursery stock, 

 and new insect enemies and new diseases 

 are being thus introduced every year. 

 Twenty different insect pests, new to 

 the United States, some of them very 

 formidable in the Old World, have been 

 intercepted in the inspections of the 

 imported material by this department 

 this year, aud this does not include the 

 introduction of brown-tail moth nests 

 and other European pests with imported 

 seedling stock. 



A properly enforced quarantine and 

 inspection law in the past would have 

 excluded many, if not most, of the 

 foreign insect enemies and plant diseases 

 which are now levying an enormous 

 annual tax, amounting to several hun- 

 dred million dollars, on the products of 

 the farms and orchards of the United 

 States, 



