PESTS OF THE HOP CROP. 141 



I am not prepared to say that this same mite is 

 found in American hop fields, but in September, 1887, 

 Mr. Pergande found at Waterville, N. Y., a species 

 closely related to the common red spider of green- 

 houses, which occurred in large numbers on the lower 

 side of many leaves of the hop plants, doing consider- 

 able damage to the foliage and covering themselves 

 with a web just as the spinning mite of the hop fields 

 of England is reported to do. It bore a strong super- 

 ficial resemblance to the common so-called red spider, 

 but had six-jointed legs instead of seven-jointed legs. 



Professor Osborn, in Wisconsin, in September, 

 1887, found what he took to be the true Tetranychus 

 tclarius in almost every hop yard visited, and in some 

 so plentiful as to cause conspicuous injury to the leaves. 

 It should be stated that in Wisconsin that summer the 

 hop plant louse seemed to be entirely absent. He 

 found eggs, young mites and full-grown mites abun- 

 dantly under the very delicate web spun over the under 

 surface of the leaf, the upper surface indicating their 

 presence by rusty patches and a red or yellow discolor- 

 ation. No attack was made on the burr, so that the 

 damage consisted simply in loss of vitality to the plant. 

 The growers generally did not consider the mite as of 

 any importance. Prof. Osborn has suggested the 

 obvious remedy of burning the plants as soon as they 

 become dry enough to burn after picking. Thus, there 

 is a possibility that the European mite already occurs 

 in this country, and that trouble may ensue in excep- 

 tional seasons. 



PRACTICAL DIRECTIONS FOR SPRAYING 



Such poor results from spraying have been 

 reported that in addition to Dr. Howard's very com- 

 plete and scientific exposition of the subject, we add 

 some directions and experiences from practical grow- 

 ers who have successfully applied the foregoing meth- 

 ods. Writing for Washington state ; Hart says: 



