REPORT OF THE DIVISION OF ENTOMOLOGY AND BOTANY 83 



SESSIONAL PAPER No. 16 



The Pear-Leaf Blister Mite, as its name implies, is not on insect, but a mite. It 

 is a microscopic creature, being only about M25 of an inch in length. Regarding the 

 life habits of these mites, Prof. Parrott, of the New York Agricultural Experiment 

 Station, says : ' The mites spend the winter in the buds usually under the second and 

 third layers of bud-scales. They frequently collect in colonies of fifty or more in little 

 depressions in the scales and are more or less concealed and protected by the pubes- 

 cence of the buds. As the buds burst, the mites move to the unfolding leaves in which 

 they burrow and establish new colonies. In October the mites abandon the leaves and 

 hide in the buds.' 



The irritation caused by the mites burrowing into the leaves from below, induces 

 the growth of galls, or blisters. Within the blisters the eggs are laid; these hatch in 

 a few days and the young mites feed upon the juices of the leaf. If the blisters are 

 examined closely, tiny openings will be seen ; these are made by the mites on entering 

 and leaving the leaf. The chief injuries by the Blister Mite are to the leaves, but the 

 fruit stems and fruit are often attacked. Prof. Lochhead in writing of this pest, in 

 the Annual Report of the Fruit Growers' Association for 1908, says : ' The galls on 

 pear leaves are at first greenish, then reddish, afterwards bright red, and finally with 

 the death of the affected tissues, brown or black, often most conspicuous on the sides 

 of the midrib. When the mites are very numerous the injuries produce defoliation of 

 the trees. The colour of the galls on apple leaves is much less striking than that on 

 pear leaves. The galls are usually more abundant on the margins of the leaves, and are 

 at first greenish, soon becoming brownish, and only occasionally red. The coalescence 

 or merging together of several of the galls produce irregular-shaped dead areas, which 

 often rupture at the margin.' Quoting from Prof. Parrott, he says : ' About July 

 first the most striking effects of the mites upon the leaves appear, especially if there 

 is much yellowing of the foliage, as frequently occurs. Upon the upper surfaces of 

 such leaves the mite-infested spots are of a light brown or of a dark green colour, and 

 are uniformly brown beneath. These spots are thickly massed, forming a dark, broad 

 band of irregular width along each side of the leaf, which contrasts coi ^ 



with the intervening light yellow area about the main rib. To one standi, 

 ground and viewing the leaves from beneath, this striping of the leaver 

 suggestive of the variegated foliage of certain ornamental plants.' 



The remedy for the Pear Leaf Blister Mite is to spray the trees with th„ 

 sulphur wash just as the buds are swelling. Although the mites pass the winter hicu_. 

 away securely beneath the bud-scales, the expanding of the buds in spring opens the 

 bud-scales sufficiently to allow the entrance of the spraying mixture. 



DONATIONS TO COLLECTIONS OF INSECTS AND PLANTS. 



Among the more important donations to the collections of insects and plants of 

 the "Division of Entomology and Botany, which have been made during the year ending 

 March 31, 1909, the following may be mentioned: — 



J. R. Anderson, Victoria, B.C. Pressed botanical specimens of Delphinium 

 menziesii, and other interesting plants. 



G. Chagnon, Montreal, Que. A fine specimen of the noctuid moth Graphiphora 

 furfurata. 



Norman Criddle, Treesbank, Man. Many specimens of rare Manitoban lepidoptera. 



Horace Dawson, Hymers, Ont. Specimens of arctian and noctuid moths of 

 special interest, taken at Hymers. 



W. A. Dent, Sarnia, Ont. Seeds and living roots of Dioscorea villosa. 



Rev. H. Dupret, Montreal. Fine specimens of Chceropkyllum sativum, Anthriscus 

 cerefolium, &c. 



Miss B. Green, Fairview, B.C. Several pressed botanical specimens, including 

 Pedicularis langsdorffii. 



