FOREST INSECTS AND FUNGI 12$ 



In June, 1909, some of the stock thus imported into New York 

 State was found to be infected with this fungus and on exami- 

 nation it was discovered that stock imported into other states 

 was Hkewise diseased. In fact the fungus has been found on 

 trees imported several years previous to 1909, which makes its 

 eradication somewhat more difficult. In nearly all cases the 

 diseased stock has been traced to one European nursery, that 

 of J. Heins Sohne, of Halstenbek, Germany. The fact that this 

 immense nursery, one of the largest in the world, should know- 

 ingly export to this country diseased stock, should deter Amer- 

 icans from all future dealing with it, even after this disease has 

 been exterminated. 



In Europe this species of Peridemiium has long been common 

 on Finns cembra, or stone pine, which is the European variety 

 of white pine. Of late years with the multipKcation of planta- 

 tions of our American species throughout Europe the disease 

 has attacked these. In some regions it has caused much havoc 

 especially in nurseries. In certain places, notably, in Holland; 

 at Oldenburg, Germany; and at Moscow, Russia, the disease 

 is so serious that the cultivation of white pine has been aban- 

 doned. Young trees are killed outright by the disease, and the 

 small branches of large trees are killed. 



The affected seedlings have a peculiarly stunted appearance, 

 and the stem is abnormally enlarged and swollen in places. 

 New growth is very short. The orange fruiting bodies on the 

 stem, which, however, occur only in the spring, furnish the best 

 means of identification. 



This fungus is one stage of the bhster rust of currants and 

 gooseberries known as Cronatimn rubicola. In other words, 

 like the wheat rust, cedar apple, and many similar fungi, it is 

 a fungus which requires two hosts to complete its fife history. 

 The spores from an infested currant or gooseberry bush are 

 blown to a neighboring white pine tree. Here they germinate 

 and the mycelium vegetates in the inner bark until the second 

 spring after infection. Then the diseased bark thickens and 

 the stem becomes swollen. The fruiting bodies break through 



