BUREAU OF PLANT INDUSTRY. 215 



all these checks gave an efficienc}' in excess of 9G per cent. The eradi- 

 cation of Eibes is directed by State cooperators, but Federal inspectors 

 are employed constantly to check the efficiency of the work. The 

 Federal ofKce also keeps a careful statistical record of work performed 

 in each State, which is of value in further perfecting methods and 

 reducing costs. 



BUSTER RUST IN THE ROCKY MOUNTAIN AND PACIFIC COAST STATES. 



The work in the western United States has been (1) locating and 

 inspecting every blister-rust host that is known to have entered this 

 territory from a region where the disease was present; (2) searching 

 for violations of the Federal quarantine against shipping five-leaved 

 pines and currant or gooseberry plants west of the Great Plains; and 

 (3) a general examination of wild and cultivated Kibes and native 

 five-leaved pines for the disease. 



During the past three seasons about 7,000 planted white pines and 

 over 200,000 cultivated gooseberry and currant bushes shipped into 

 the far West prior to the establishment of the Federal quarantine 

 have been located and inspected. Limited general scouting for the 

 disease has been done in each Western State. 



The white-pine blister rust {Cronartlum ribicola) has not been 

 found on either Kibes or pines in the Kocky Mountain and Pacific 

 coast regions. A Cronartium found on Kibes in Utah, Colorado, 

 Nevada, California, Arizona, and New Mexico has been identified as 

 C. occidentale. the alternate stage of a Peridermium occurring on the 

 piiion pines. This rust has never been found to attack white pines, 

 but in many places neighboring pinon pines a few feet from them 

 have been heavily infected for maii}^ years. Examinations of nu- 

 merous white-pine plantations in Europe made recently by Mr. W. S. 

 Moir, of this bureau, show that Pinus lamhertiana^ P. monticola., and 

 P. fiexiUs, all natives of our western regions, are as readily infected 

 and as severely injured by white-pine blister rust as Pinus strohus. 



If the white-pine blister rust is introduced into the West, enormous 

 losses will result, both in private holdings and in the National Phor- 

 esis. Due to the fact that much of the western pine is not accessible 

 to market, the destruction would be severe in mature stands, and 

 reproduction of five-leaved pines would be entirely i)revented over 

 most of the western whito-pine areas because of the abundance and 

 general distribution of wild Kibes. Sixty-five species of wild Kibes 

 are indigenous to western North America. Out of this large number 

 can be found species adapted to nearly every site and condition oc- 

 curring in these regions. The constant occurrence of these secondaiy 

 hosts would afford unbroken chains for the dissemination of the 

 white-pine blister rust. The blister rust was introduced from Europe 

 into the eastern United States only about 20 years ago. Its rapid 

 progress in that time leaves no doubt as to what it Avill do in the 

 far West if it is permitted to become established there. 



NEMATODE INVESTIGATIONS. 



PKEDATOUY NEMAS. 



Attention is being given to the subject of predatory nemas and 

 their possible utilization. Initial attempts are being made, some of 

 them successful, to introduce and rear some of these u.seful species. 



