FUNGOUS AND OTHEE DISEASES. 7l 



experiments made by Doctor Smith were barren of results, one yielded 

 rather notable success. This was in the orchard of Mr. Horace 

 Roberts, at Fellowship, N. J. Twigs from Florida bearing San Jose 

 scales infested by the fungus were tied to branches of infested trees 

 about the middle of June. Toward the end of September Doctor 

 Smith found the fungus upon almost all of the trees upon which twigs 

 had been tied. He reports that it had spread pretty well over the 

 trees, and in some cases its presence was obvious from the surface of 

 the ground to the extremity of the branches, hundreds of patches of 

 the orange fruiting processes being everywhere noticeable. In no 

 case, however, so far as Doctor Smith observed, had the disease spread 

 to an}^ adjacent trees, unless in a less visible stage, and by no means 

 all of the scales on the trees containing these twigs were dead. 



Various saprophytic fungi which develop in diseased or dying wood 

 are sometimes so closely associated with the scale, or in fact grow on 

 the scale as well as on the wood, that the inference is a very natural 

 one that the scale is being killed by these fungi. Examples of two 

 such fung-i have recentlv been sent to us for examination and were 

 submitted to the Laboratory of Plant Pathology of this Department 

 for investigation. The following report indicates their nature: 



We find two species of fungi present upon these specimens. The most conspicuous 

 form is Micropera cotoneastri (Fr. ) Sacc. The fungus forms small, black, somewhat 

 pulvinate masses on the surface of the bark, sometimes covering old scales. The 

 plant is not mature and shows in only a few instances pycnospores. It is not an 

 uncommon fungus upon diseased or dying branches of fruit trees and other closely 

 related rosaceous plants. Its relation to the scales present is probably always acci- 

 dental. The fungus probably develops more readily upon the twigs which have 

 been injured or partially killed by the scale. 



There is also another fungus present in a considerable quantity on some of the 

 twigs. It consists of minute black, slender stipitate bodies a few millimeters high. 

 This is also immature, showing only conidia. It is i>rohsi'b\y Spinctrina cerasiB. & C. 

 In the absence of the ascigerous form of the fungus it is impossible to state positively 

 that this IS the species. As in the case of the other fungus mentioned, it probably 

 bears no parasitic relation to the scales present, as it usually occurs on dead or dying 

 branches of fruit trees. 



The first fungus mentioned (Micropera) is the one most closely associated with the 

 scales. 



The plan of using contagious insect diseases to destroy important 

 pests, such as the San Jose scale, is a very attractive one, and in the 

 case of the San Jose scale well worthy of more careful study than has 

 so far been given it. It is possible that some of the obscure forms of dis- 

 ease which have already appeared in northern districts, as in Maryland, 

 Virginia, and in the State of Washington, may be capable of artificial 

 propagation and distribution, and yield results of distinct value in the 

 control of the scale. All of these fungous and other diseases will 

 undoubtedly become more efficient with the more wide and general 

 distribution of the scale. 



