GALLS CAUSED BY MITES 105 



make their blind leap. Perhaps the mite succeeds in 

 'boarding' a passing insect which hovers near enough to 

 fan it by the beating of its wings."* 



Attacked buds may be at once recognized by their swollen 

 and distorted appearance. The life-history of this mite has 

 been fully investigated by Embleton, Collinge, Warburton, 

 and other economic zoologists. A summary of their obser- 

 vations, together with preventive and remedial measures, 

 may be consulted in Leaflet No. i, published by the Board 

 of Agriculture and Fisheries. 



The Pear-leaf blister mite, Eriophyes pyri Nalepa, is also 

 on the increase in this country. It causes raised greenish or 

 red patches or blisters on the leaves, and sometimes on the 

 fruitlets. It is a very minute species, quite invisible to the 

 unaided eye. It passes the winter under the outer scales of 

 the buds on young shoots. " It does not appear as an 

 epidemic. Trees often remain unattacked in a garden, 

 though in close proximity to badly infested trees." For 

 particulars concerning treatment of this pest, see Leaflet 

 No. 239, Board of Agriculture. This mite attacks various 

 other rosaceous plants, such as the Apple, Service tree, 

 Mountain Ash, and the rare Cotoneaster vulgaris. 



On the Continent Eriophyes Kerneri Nalepa attacks various 

 species of Gentiana ; in all cases malformatiop and discolora- 

 tion of the floral organs, often with " doubling," result, and 

 the inflorescence of many Labiate plants is reduced and 

 covered with a velvety pile under the influence of various 

 mites, notably E. Tkomasi, which infests many species. 



Theobald, in his first Report of economic zoology (1903), 

 alludes to a phytoptid disease in violets, causing the leaves 

 to curl tightly over at each side and become greatly 

 deformed. The mites were green, and large enough to be 

 seen easily with a hand-lens. Specimens were sent to 

 Dr. Nalepa, who considered it to be a hitherto unrecognized 

 species. He described it under the name of Eriophyes violae. 



* Alice L. Embleton, Knowledge, September, 1903, p. 234. 



