1650 



ENCYCLOPEDIA OP PRACTICAL HORTICULTURE 



Fig. 1. Pear Leaf Blister Mite Injury on Pear Leaves. 

 (Montana Experiment Station) 



main the color of the leaves. The younger 

 shoots suffer most. The mites are very- 

 minute and can be seen only with the aid 

 of a microscope. The body is elongated, 

 with roughened surface, transparent and 

 having but two pairs of legs near the 

 head. 



Life History 

 The mites pass the winter on the trees 

 under the bud scales and begin to work 

 upon the leaves as soon as they appear 

 in the spring. The eggs are deposited 

 in holes bored into the underside of the 

 leaves. The work of the young after 

 hatching causes the galls or swellings. 

 The destructiveness continues through- 

 out the summer and until the leaves 

 begin to fall in winter. There are sev- 

 eral generations each year. 



Food Plants 



The pear and apple are seriously 

 affected, the mites attacking the foliage 

 as well as the stems of the leaves and 

 fruit. On the foliage of the pear the 

 galls are made along the sides of the 

 midribs of the leaves; on the apple at 

 the base and along the margins of the 

 leaves. Other plants found as hosts are 

 white beam tree, European mountain 

 ash, wild service berry, common coton- 

 easter. 



Control 



Same as for the 

 spotted spider or 

 Mmaculatus Harv.) 



common red or six- 

 mite. ( Tetranychus 







E. 0. EssiG 



Borers, 



various 



species. See Apple 



Pests. 







Bud Worm 



Bud worms may be controlled by spray- 

 ing with either Paris green, arsenate of 

 lead or Bordeaux arsenical when leaf 

 buds open. Repeat in six days if neces- 

 sary. 



California Tussock Moth. See Apple 

 Pests. 



Cherry Scale. See Cherry. 



Cigar Case Bearer. See Apple Pests. 



Citrus Thrips. See Orange Pests. 



Citrus White Fly. See Orange Pests. 



Climbing Cutworms, various species. 

 See Apple Pests. 



Codling Moth. See Apple Pests. 



Cotton Maple Scale. See Apple Pests. 



Eye-spotted Bud Moth. See Apple 

 Pests. 



Fall Canker Worm. See Apple Pests. 

 Fall Web Worm. See Apple Pests. 



