1910 ENTOMOLOGICAL SOCIETY. 91 



Again, specimens were found even in the solid rock, where, without any apparent 

 means of sustenance, these active little/ creatures seemed to thrive. An example of 

 this species is Scutovertex petrophagus, found at Trahanic Falls near Ithaca, N.Y. 



Bush and Fruit Tree Pests. 



In Canada and other countries mites that attack bush and fruit trees are 

 among the more serious pests of the fruit growers. In Canada they are found 

 on the apple, plum, pear, etc., and in tropical countries they are very destructive 

 to citrous fruit trees. Examples attacking the apple tree are the Pear Leaf Blister 

 mite, EriopJiyes pyri, which is widely distributed throughout most of the 

 apple growing region. They form red blister-like spots about one-fourth of an 

 inch in diameter, which turn brown in late summer, the tissues becoming hard 

 and corky. Three or four other species belonging to the genus Eriophyes have 

 not such economic importance. The same species found on the apple are found 

 attacking the pear and other trees belonging to the genus Pyrus. Another 

 injurious species attacking the plum tree in the Niagara district is the Plum 

 Twig Gall mite, Eriophyes pklcco copies. It is an European species which has 

 been imported into this country witliin recent years. The mites form small sub- 

 spherical galls in clusters at the base of the buds. Pocket-like galls belonging to 

 the genus Eriophyes are found on the leaves of the cherry, plum, and grape. Two 

 species of red spider, Tetranychus telarius and Bryohia pratensis, are found on 

 the under side of the leaves of the plum, pear and apple, and when in large num- 

 bers, as they usually are in dry seasons, they do a considerable amount of injury 

 to the common fruit trees. One species confines its ravages to the secretions on 

 the surface of the apple. The red spider is also found on the raspberry. On 

 currant bushes in England a species known as the Black Currant Gall mite, Erio- 

 phyes ribis, has long been known to horticulturists in that country, and as it is 

 spreading rapidly in England and other countries, its presence here may be 

 expected any day. In shape this particular species is easily recognized by the 

 distinct globular or swollen-like appearance of the buds. When the buds are 

 badly attacked they never open into leaf, but for a time they retain their green 

 colour, later becoming brownish, dry, gall-like bodies, more or less open at the 

 apex. Another species of considerable economic importance in the tropics is Erio- 

 phyes oleivorus, the rust mite of the orange and the silver mite of the lemon. It 

 occurs in California and lives on both leaves and fruit. On the foliage the mite 

 causes the leaves to become curled and to lose their gloss. On the fruit of the 

 orange the mite produces a hardening of the rind, which becomes brownish in 

 colour. The infested orange, although injured in appearance, is better able to stand 

 long shipment and is more juicy than the clean fruit. Upon the lemon the mites 

 cause the rind to become silvered, the fruit is better for shipment but the rind 

 is injured for commercial purposes. 



As Pests of Farm and Garden Crops. 



As enemies to the growing grain and also to stacked roots such as turnips, 

 carrots, mangels, potatoes, and even ensilage, mites are considerably destructive. 

 Yet they are not responsible for so much damage as they are often credited with. 

 In the field the Clover mite, Bryohia pratensis, is of most importance, attacking 

 clover and other leguminous crops. Another species is found on Timothy and 

 causes distortion of the inflorescence. In the root cellars there are hcts of 

 species too numerous to mention, some parasitic, some saprophytic, and a few 

 finding it a favourite place to live, but doing no harm. 



