AGRICULTURAL EXPERIMENT STATION. 141 



Host Plants. 



From the table of host plants given below, it will be seen that 

 this mite is a genei'al feeder, attacking a wide range of both 

 glabrous and hirsute plants belonging to a wide range of families. 

 This list is no doubt far from complete, as no great pains has been 

 taken to make it exhaustive. Should this mite prove capable of 

 living out of doors it would become a double terror to horticultur- 

 ists. It at present is found out of doors only in rare instances, 

 and there is no evidence that it is as Henderson suggests, common 

 in gardens, or the same as that which produces roughness to 

 particular parts of cherry, plum and peach trees. Our experience 

 does not warrant the belief that it attacks especially plants of 

 lessened vitality. These mites, like plant lice, live by sucking 

 the juice of plants, and are pretty good judges of proper feeding 

 grounds. They are not likely to turn aside from a healthy juicy 

 plant to one of the same species that is sickly and lacking in 

 juices. They are small and would escape observation until a 

 sickly condition was produced in the host plant and attention 

 directed to it. We believe that instead of especially attacking 

 sickly plants they are the cause of lessened vitality. The 

 list of host plants given below shows that the mite has no special 

 preference for pubescent plants, in fact, some of the worst cases 

 of attack we have seen were upon glabrous species. Munson and 

 Harvey are authority for the occurrence of the mite at the Maine 

 State College green-houses and at private houses in Orono and 

 vicinity ; Prof. L. H. Bailey for the occurrence of the mite in the 

 green-houses at Cornell College, Ithaca, N. Y. ; Henderson for its 

 occurrence in their green-houses. New York City ; Dingee & 

 Conard Co. for its occurrence at West G-rove, Pa. 



