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ENTOMOLOGICAL SOCIETY OF ONTARIO. 



diluted mixture of kerosene emulsion the insects will be destroyed. A good time also to 

 spray the trees, is early in spring before the buds burst. It is a matter of surprise to some 

 how these insects which pass their lives for the most part attached firmly to the bark can 

 spread so rapidly through an orchard, as they frequently do. This has been explained by 

 the suggestion that at the time the young lice first hatch, they are very active and crawl 



Fig. 52.— Oydter-shell Bark-louse. 



Fig. 51. 



with great agility. At this time of the year, the trees are much frequented by birds ancJ 

 other insects, upon which the lice crawl and are then carried from tree to tree by these 

 larger winged creatures. 



Belonging to this same class of scale insects, is the pernicious San Jose scale which 

 on account of its importance, is treated of in a separate article. 



Another enemy of fruit trees which has this year for the first time appeared in the 

 Dominion, is the Pear-tree Flea louse, {Psylla pyricola, Forster), specimens of which were 

 sent in from Freeman, Ont., by Mr, J. S. Freeman, who writes : "I have a block of 300' 

 dwarf Duchess pear trees mixed with apple trees, whioh are so badly affected with the 

 insects which I am sending you, that from the appearance of the trees at present, the 

 whole crop will be destroyed. I do not think that the pear trees have been troubled 

 before this season. They are more or less over the pear trees of different kinds in my 

 nine-acre orchard. From inquiries of other fruit-growers in this section, I think it likely 

 that this pest occurs in other orchards too." At the time of receiving the specimens the 

 insect was in the pupal form and just about to assume the perfect state. Mr. Freeman 

 was written to as to the nature of the insect, and he was recommended to spray his trees, 

 with kerosene emulsion at the time and to repeat the application early next spring when 

 the buds burst, that being the season when the young hatch from eggs laid by females 

 which are now hibernating on the trees. This has been found to be the most successful 

 treatment. 



The Pear-tree Flea-louse belongs to the same class of insects as the aphids or plant 

 lice, with which they form the second section of the Homoptera, known as Dimera, or 

 those with two-jointed feet. In this section we find small insects with antennas longer 

 than the head and in the winged individuals four wings, ordinarily all of the same mem- 

 braneous texture. The Psyllidoi or flea-lice are small insects found on leaves and in 

 some species, as the Hackberry flea-louse, give rise to galls. They have long slender 

 antennte terminated by two bristles. The beak is short and tri-articulate, and the eyes 

 are lateral and prominent as in the Cicadae. In fact, these little flea-lice, although sel- 

 dom much more than one line in length, very much resemble Cicadae in miniature. 

 On the front of the face are three ocelli placed in a triangle, the posterior ones quite close ta 

 the eyes. Unlike the Aphides or plant lice, the flea-lice have the power of leaping, from 

 which they take their English name. 



