LOSSES CAUSED BY IMPORTED TREE AND PLANT PESTS 



By C. L. Marlatt, Chairman, Federal Horticultural Board 



In view of the fact that fully fifty per cent of the tree and plant pssts which in the past and at the present time are doing millions of 

 dollars' damage every year to the agricultural and forest crops of the United States are imported, the American Forestry Association at its 

 International Forestry Conference at Washington, D. C, January 18-19, 1917, heard addresses and discussions on the advisability of a national 

 quarantine preventing the importation of tree and plant stock from other continents, unless such stock has the approval of the United States 

 Department of Agriculture. The following is one of the addresses. — Editor. 



THE virgin lands of the new world had originally an 

 enormous advantage over the long-settled areas of 

 the old world in their freedom from the host of 

 plant enemies, insects and disease, which had developed 

 through centuries of ctiltivation of special crops, and, if 

 proper safeguards had been instituted, this advantage 

 could have been largely preserved. Unfortunately, none 

 of the countries of the new world, until very recently, 

 took any precautions to prevent the introduction of these 

 old-world plant enemies. 



Confining our attention to the United States particu- 

 larlv, as a result of this neglect, probably more than 



atively recently introduced pest, getting first foothold in 

 Utah, from whence it has extended its devastations over 

 much of the great alfalfa-producing areas of the adjoining 

 states. Among the fruit insects are such well-known 

 enemies as the codling moth, now entailing a cost for the 

 treatment of trees and loss from injury to fruit taken 

 together of approximately $16,000,000 a year; and the 

 San Jose scale, introduced with ornamental plants from 

 North China, occasioning a loss in product and cost of 

 treatment of at least $10,000,000 a year. Among forestry 

 insects are such notable enemies of forest trees as the 

 larch sawfly, which threatens to complete the destruction 



COTTON BOLL WEEVIL (ANTHONOMUS GRANDIS) 

 The cost to this country of the cotton boll weevil amounts to about twenty-five 

 million dollars a year. It is gradually spreading throughout the cotton belt, 

 and in 1916 reached northward to the South Carolina line. The picture, 

 enlarged, shows an adult boll weevil. 



fifty per cent of the insects 

 and diseases now destnic- 

 tive to our agriculture and 

 forestry are introductions, 

 most of them unnecessary. 

 Typical examples of these 

 introduced pests, in relation 

 to general agriculture, are 

 the Hessian Fly, introduced 

 from Europe in revolution- 

 ary times and now occasion- 

 ing an average annual loss 

 to the wheat crop of approx- 

 imately $50,000,000, and in 

 some years this loss has ex- 

 ceeded one hundred millions; 

 the alfalfa weevil, a compar- 



RESOLUTION 



Passed by the International Forestry Confer- 

 ence of the American Forestry Asso- 

 ciation, January 18-19, 1917 



In view of the spread of diseases and insect 

 pests introduced from foreign countries, such as 

 the chestnut blight, gipsy moth and white pine 

 blister. 



Resolved 



That the American Forestry Association favor 

 the principle of absolute national quarantine on 

 plants, trees and nursery stock, to take effect at 

 the earliest date which may be found economi- 

 cally expedient. 



BOLL WEEVIL LARV/E 

 The manner in which the larvae of the boll weevil injures the cotton boll is 

 indicated by this photograph. The ravages of this insect cost this country 

 annually 25 cents apiece for every man, woman and child. 



already largely accomplished 

 of the larch timber of the 

 United States and Canada, 

 and the gypsy and brown- 

 tail moths, which have long 

 ravaged the forests of New 

 England and have been the 

 occasion of the spending of 

 many millions of dollars in 

 control efforts and of losses 

 proportionately vastly 

 greater. For mere control 

 alone, the Federal Govern- 

 ment has carried an appro- 

 priation for many years now 

 of over $300,000 a year to 

 aid the States in the work 

 75 



