REPORT OF THE ENTOMOLOGIST AND BOTANIST. 211 



of the trees at present, the whole crop, some of the worst specimens of which I am 

 sending you, will be destroyed. I do not think the pear trees were troubled before this 

 season. Would you kindly tell me what the insects are and give a remedy 1 Would 

 it be too late to apply a remedy this season 1 Please reply. 



Reply. — " June 8. Your letter of 7th inst , with insects inclosed, is just to hand 

 and is of great interest. I wish you had written a little sooner in the season. The in- 

 sects sent are the Pear-tree Psylla (Psylla pyricola), a pest which has done great injury 

 in the States of New Jersey and New York. This is the first record of its appearance 

 in Canada. It is a serious pest, and must be fought vigorously at once. The remedy 

 is Coal-oil emulsion. (See page 12 of bulletin 11 sent herewith). Instead, however, of 

 mixing the stock emulsion with nine times its quantity of water, I would suggest your 

 using 12 times the quantity of water first, and see how that works. I shall be obliged 

 if you will write me at once and let me know how long it is since you first noticed this 

 pest, and if it is very prevalent in your district 1 



" The presence of this insect is always indicated by a sticky exudation noticeable 

 on the twigs, called honey dew. Upon this, later in the season, a black fungous mould 

 grows which gives the tree a very dirty and unsightly appearance. I cannot impress 

 upon you too strongly the importance of treating this pest at once, and if possible 

 checking its spread. Please let me know if you or any of your neighbours have recently im- 

 ported trees from the States of New Jersey or New York. I shall be glad to give you 

 any further information in my power." — J. F. 



" Freeman, June 13. — I am much obliged for the information your letter brought 

 me on the 11th inst. I have applied the coal-oil emulsion as you recommended on my 

 Duchess Dwarf trees, which are 12 years old, in 12 times and not 9 of water as in 

 formula ; but besides being on these, I find the insects are more or less over my other 

 pear trees of 9 acres of different varieties. I knew from the appearance of my trees 

 that something unusual was attacking them ; but I did not make a close examination 

 of them until two days before I wrote you. This must be the first season this pest has 

 been bothersome, or I should have noticed the fungous growth last season if it had been 

 there as this. From inquiry of fruit-growers in this section, I think it is likely that 

 this pest may be found in other orchards. The oi^iginal trees in my orchard came some 

 15 years ago from Lockport, N.Y., and I have, with many of my neighbours, planted 

 more or less pear trees every spring since, all the trees coming from the same place, 

 Lockport. Any more information as to destroying this pest, will be gladly received." — 

 J. S. Freeman. 



Several articles have lately appeared upon the Pear-tree Flea-louse. By far the 

 most complete study of the subject has been made by Mr. Mark V. Slingerland, 

 of Cornell University, and the results of his labours have been published as Bulletin 44 

 of the Cornell University Agricultural Station. In this a full history is given of the 

 development and habits of the insect, illustrated by excellent figures, of which Nos. 15 

 and 1 6 have been kindly lent for this article. Winter is passed in the perfect state, the 

 males and females hiding in crevices and beneath flakes of bark on the pear-trees. In 

 the first warm days of spring, the date varying with the season, they emerge from their 

 winter quai'ters, and after mating, " the egajs are laid in the creases of the bark or in old 

 leaf scars, about the bases of the terminal buds of the preceding year's growth ; some 

 were seen about the side buds near the terminal ones. * * * * * 



The eggs are scarcely visible to the unaided eye. It would take eighty placed 

 end to end to measure an inch. They are elongate, pyriform in shape, smooth 

 and shiny, of a light orange yellow colour when first laid, becoming darker before 

 hatching. A short stalk to the large end attaches the egg to the bark, and a long 

 thread-like process projects from the smaller end. The temperature conditions in the 

 spring influence not only the time of oviposition of this winter brood, but also the du- 

 ration of the egg stage. The weather remaining cool, eggs upon the trees under natu- 

 ral conditions, did not hatch until May 10, or more than a month after oviposition began." 



The young nymphs immediately on hatching, suck the sap. Mr. Slingerland found 

 that a few nymphs emerged in spring before the leaves had 'expanded ; these 

 crawled into the buds out of sight. The favourite feeding places of the nymphs to 



8c— 14i 



