1652 



ENCYCLOPEDIA OF PUACTICAL HORTK^ULTURE 



lu this district this mite seems to be 

 of economic importance to the pear grow- 

 ers. The injury resulting from its pres- 

 ence in the pear orchards is generally 

 apparent during the latter part of June 

 or early July. The foliage has a peculiar 

 rust or russet appearance on the under 

 side and is also somewhat curled, as 

 though by drought. There may be some 

 slight russeting on the upper side, but 

 this is rather uncommon. The terminals 

 of shoots are also attacked and have the 

 same brownish appearance of the under 

 surface of the foliage. Where the attack 

 is serious, the whole tree has a brownish 

 appearance and the trouble has been 

 given the local name "rusty leaf" by the 

 fruit growers. During the latter part of 

 July and through the month of August, 

 badly injured trees shed the foliage from 

 their terminals. The terminals have a 

 somewhat shriveled appearance, the epi- 

 dermis being brownish-black or black. 

 Very often the injured epidermis is 

 cracked or broken, due to the expansion 

 of the growing tissue beneath. The fruit 

 is also attacked and is russeted and 

 cracked in the same manner as the ter- 

 minals. 



The injury to young pear trees is 

 usually greater than to older bearing 

 ones. Sometimes almost complete defo- 

 liation of the young tree results before it 

 has had its season's growth, and besides 

 the epidermis of the growing shoots has 

 been injured. Fortunately, this mite is 

 very easy to control. As in the case of 

 all of our economic species attacking 

 plants, the use of lime-sulphur, dry sul- 

 phur, oil emulsions, etc., will completely 

 control it. Since it is a surface-feeding 

 mite, producing no galls, it would seem 

 that there should be no trouble in erad- 

 icating it. P. J. CGara, 



Pathologist, Medford, Ore. 



Notch Winij 



Ennomos magnarius Guen. 

 This caterpillar appears occasionally 

 upon pear and apple as well as a large 

 number of other plants. Its distribution 

 Is quite general, but it does not seem to 

 be Important economically. Wherever 

 spraying is done for codling moth, this 



species is not likely to become abundant. 



Oblique Banded Leaf Roller. Sci 

 Apple Pests. 



Oyster Shell Scale. See Apple Pests. 



Pear Blight Beetle. See Shot Hole 

 Borer, under Cherry Pests. 



Pear Leaf Blister Mite. See Blister 

 Mite, this section. 



Pear Leaf Miner 



Ornix geminatella 

 The pear leaf miner is a very small, 

 dark, steel-gray moth, expanding about 

 one-third of an inch. The larva mines in 

 the leaf tissues of both apple and pear. 

 It sometimes draws two leaves together, 

 tying them with silken fibers; again, it 

 may fold up in a single leaf. Since it 

 passes the winter inside the fallen leaves, 

 as a larva, or as a pupa, its numbers can 

 be thinned, if it should become numerous, 

 by collecting and burning the leaves soon 

 after they drop in autumn. 



H. A. Gossard, 

 Wooster. Ohio. 

 Pear Psylla 

 Psylla pyricola Foerst. 

 General Appearance 

 Adults are small, orange yellow, jump- 

 ing insects, not unlike miniature cicadas. 

 More common than the adults are the 

 nymphs, which are queer looking creat- 

 ures with wide flat bodies and large 

 heads. The general color is orange with 

 dark striped thorax and blackish-brown 

 abdomen. In the mature winged form 

 the abdomen is greenish. 



life History 



The insects appear with the first 

 healthy growing shoots, which they at- 

 tack vigorously. They increase rapidly 

 and often do great damage. All stages 

 are to be found throughout the summer 

 months. 



Food Plant 



The pear. 



Control 



Same as for plant lice (Aphididae), 

 consisting of soap and emulsion sprays. 



Natural Enemies 



The two-spotted ladybird beetle (Adalia 

 bipiinctata Linn.) and the green lace- 

 wing (Chrysopa califoriiica Coq.) feed 



