y' THE PLUMS OF NEW YORK. 131 



side of a fruit but in other cases distributed over the whole surface. None 

 of the cultivated species are free from the disease but the Munsoniana, 

 and Hortulana varieties are most susceptible to it. Pear blight,' 

 {Bacillus amylovorus (Burrill) DeToni) commonly thought of as a 

 disease of the pear and apple has been found on various plums, and the 

 yellows of the peach, cause unknown, is often quite destructive to Tri- 

 flora plums. According to Smith the peach rosette,' cause unknown, 

 attacks both wild and cultivated plums in the South and is quickly fatal. 

 The disease was prevalent on the wild Angustifolias, on two varieties of 

 Trifiora, Kelsey and Botan, but the observer had not seen rosette on 

 varieties of Domestica. 



Waugh describes a trouble which he calls " flyspeck ftmgus " ' fotmd 

 on fntits sent from the Southern States, in which small areas are thickly 

 dotted with black spots; also a fruit-spot on pliuns from Texas caused, 

 as he states, by an im determined Phoma.* Stames of Georgia describes 

 a malady of the Trifiora plums called " wilt," ' cause unknown, which 

 he states is the most serious obstacle to the culture of this plum in the 

 South. In this peculiar disease the foliage passes directly from a green, 

 healthy state into a wilted and then parched condition, the death warrant 

 being signed when a tree is once affected. In Oregon and Washington 

 the Italian Prune is subject to a leaf -curl ' which begins in mid-summer 

 and curls the leaves conduplicately without withering but shriveling some- 

 what. As the season advances the leaves turn yellow and many of them 

 drop. Neither cause nor cure is known. Smith described a plum-blight ' 

 of native plums in Georgia which " destroys large branches or even whole 

 trees in mid-summer in the course of a few weeks." 



INSECTS. 



Cultivated plums furnish food for a great number of insects. Many 

 of the destructive insect pests of the several cultivated species of Prunus 

 are known to have come from the wild plants of the genus, but others, 

 and possibly the majority, come from over the seas. No less than forty 



'Jones, L. R. Studies upon Plum Blight Vt. Ex. Sta. Rpt. 15:231-239. 1902. 



"Smith, E. F. The Peach Rosette Jour. Myc. 6:144. 1891. 



•Waugh, F. A. Plum CuU. 329. 1901. 



' Ibid. 



'Stames, H. N. Japan and Hybrid Plums Ga. Sta. Bui. 68:22-24. 1905. 



• Hedrick, U. P. Curl-leaf of the Italian Prune Oreg. Sta. Bui. 45:72-74. 1897. 



' Smith, E. F. Field Notes Jour. Myc. 6:108. 1891. 



