FEDERAL HORTICULTURAL, BOARD, 625 



way the spread of this scale, in Texas and other Southern States, 

 through the agency of the Alvin, New Orleans, and other nurseries. 



The camphor scale is a new pest to the United States. It ap- 

 parently gained entry and establishment just prior to the passage of 

 the plant quarantine act, and therefore before there was any Federal 

 authority to safeguard the entry of the plants responsible for its in- 

 troduction. The origin of this scale in Alabama is apparently trace- 

 able to very large importations of trifoliate oranges direct from 

 Japan in 1911. The infestation at New Orleans may have resulted 

 from some distribution of a portion of this importation, if not from 

 some independent importation of plants from Japan about the same 

 time. It took nearly 10 years for this scale to develop in sufficient 

 abundance to attract notice, but some three years ago its injury 

 to camphor trees in New Orleans became serious, and the scale was 

 found to be widely disseminated within the city on a long list of 

 host plants. The city and State immediately undertook an effort 

 to control and, if possible, to eradicate it, and have already spent 

 upward of $30,000 in such work. 



The determination of infestation in Alabama, near Mobile, was 

 made in 1921 in orchards of Satsuma oranges grafted on the im- 

 ported trifoliate stock. The work of this scale in these orchards 

 indicates the serious menace which it presents to the citrus cultures 

 in this country, in addition to its previously known importance as 

 attacking camphor and many other ornamental plants as well as 

 various deciduous fruits, such as olive, persimmon, fig, plum, and 

 pecan. 



POTATO WART. 



The known distribution of the potato wart in Pennsylvania, West 

 Virginia, and Maryland remains unchanged. No further survey has 

 been conducted, but dependence has been placed on collaborators in 

 the plant-disease survey of the Bureau of Plant Industry and on 

 county agents and other agricultural correspondents to report any 

 new points of infection. 



Two modifications of the Pennsylvania quarantine have been put 

 into effect, as follows: 



An amendment to the State quarantine law makes it possible for 

 quarantine inspectors to confiscate and destroy any potato plants of 

 other than approved immun(^ varieties which are found in the quar- 

 antined areas. This has enabled the inspectors to begin their work 

 in June, as soon as varietal characteristics are evident, and to remove 

 susceptible plants before infection occurs. Previously it has been 

 necessary to jjrove that the plant is infected before it could be re- 

 moved, and usually this could be done only after the infection had 

 progressed to such a stage that a new crop of resting spores of the 

 parasite had been released into the soil, thus prolonging the latent 

 existence of the disease. 



Due to widespread dissatisfaction of the commercial potato grow- 

 ers in the agricultural districts surrounding the Freeland infested 

 area with the immune varieties which they were required to grow, 

 particularly the Green Mountain variety on account of its suscepti- 

 bility to common scab, the requirement of planting only immune 

 varieties in this "safety zone" was temporarily withdrawn. The 

 prevalence of scab in the Green Mountain variety was in part due 



