76 



AMERICAN FORESTRY 



against these insects. Other notable forest and shade tree 

 pests are the spruce twig moth, comparatively recently 

 introduced, the leopard moth, and the elm beetle. 



These are merely examples of a vast horde of intro- 

 duced insect pests. Upwards of a hundred distinctly 

 important injurious insects to agriculture and forestry 

 have been thus introduced, and, in addition to these, 

 hundreds of other minor insect pests. The total 

 loss occasioned by these introduced insect pests to our 

 national forests and farm crops, etc., probably exceeds 

 $500,000,000 annually. 



Losses correspondingly large are chargeable to intro- 

 duced plant diseases. Familiar examples of such intro- 

 duced diseases are, the chestnut blight, which has already 

 destroyed the chestnut forests over much of the eastern 

 United States and threatens the existence of the entire 

 native chestnut growth of the country; the white pine 

 blister, a disease already widespread in the eastern white 

 pine area and which ultimately will cause enormous loss 

 to all white pine forests, and which losses will be vastly 

 increased should it spread to the great white and five- 

 leaved pine forests of the Rocky Mountain and Pacific 

 Coast States. Introduced diseases affecting cultivated 

 plants include such important examples as the common 

 scab of the potato, of almost universal occurrence in this 

 country and occasioning tremendous shrinkage in the 

 value of this important crop; the wheat rust, which in 



bad years may 

 practically 

 wipe out the 

 entire wheat 

 crop of large 

 sections, as 

 was the case 

 last year in 

 Red River 

 Valley; and a 

 corn mildew 

 recently intro- 

 duced and al- 

 ready accom- 

 plishing very 

 serious losses 

 in the South. 

 Among dis- 

 eases affect- 

 ing fruits and 

 fruit trees, the 

 most notable 

 example is 

 the citrus 

 canker, a dis- 

 ease recently 

 introduced 

 from Japan 

 or Asia, and 

 threatening 

 the very exist- 



STOPPING THE CODLING MOTH ence of much 



An apple tree banded in order to collect the larvae of the r , - 



codling moth so that it may be destroyed. Ot the enor- 



THE BROWN-TAIL MOTH (EUPROCTIS CHRYSORRHCEA) 



The brown-tail moth was imported by a Boston florist about 26 years ago on 

 roses from Holland and France. It is a serious enemy to the orchard, forest, 

 and shade trees, and ornamental shrubbery, and has long been recognized as 

 one of the worst orchard pests of Europe. The hairs on the caterpillars produce 

 the brown-tail rash, often causing considerable annoyance to the residents of 

 infested districts. 



THE CODLING MOTH (LASPEYRESIA POMONELLA) 



The codling moth, or apple worm, occasions a loss, in cost of spraying trees 

 and injury to the fruit, of sixteen million dollars a year in the United States. 



