72 THE REPORT OF THE [ No. 19 



of \phich mines in apple leaves and sometimes does rather noticeable injury when abundant, 

 is Nepticula poniivorella, Pack. The larva when full-grown leaves its mines in the foliage 

 and spins small scale-like brown cocoons on the twigs where it passes the winter. This 

 insect was formerly placed in the genus Micropteryx but it has been discovered by Mr. 

 Busck of Washington that it is a true Nepticula. 



Pear trees have suffered rather more than usual from three of their enemies. The 

 Cherry Slug in some places has stripped the green cellular parts from the foliage to such 

 an extent as to render the leaves quite useless to the trees, and as a consequence the fruit 

 was ruined. This insect can be very easily kept in check either by spraying with arsen- 

 ical poisons or by dusting constantly with freshly slaked lime. The Pear Paylla was 

 particularly troublesome at Freeman, near Hamilton, and through the western counties. 

 Mr. Geo. E, Fisher considers this an insect which requires much more attention than up 

 to the present it has received. The mature insect hibernates beneath the flakes of bark 

 on the trunks and larger limba and can be destroyed during the winter by a 30 per cent, 

 mechanical mixture of crude petroleum and water, or by the ordinary kerosene emulsion. 

 The Pear-leaf Blister-mite is not quite as bad as it was a year or two ago but still is 

 much more abundant than is good for the pear trees or the pocket-book of the fruit 

 grower. On the Pacific Coast this insect is kept well in check with the lime, sulphur 

 and salt mixture. This mixture has not been used very much in Ontario but the well- 

 known kerosene emulsion sprayed over the infested trees just as the buds are bursting 

 has been found very effective. Doubtless the mixtures of crude petroleum and water 

 which are now coming so much into use will be found very effective against the Pear- 

 leaf Blister- mite as soon as the proper portion to use with safety has been discovered. 



INSECTS Ob' THE SEASON OF 1900. 



By Prop. W. Lochhbad, Ontario Agricultural College, Guelph. 



In looking backward over the entire season of 1900 it would appear that insect 

 pests were more numerous and produced greater losses than usual. It is very difficult to 

 determine the exact causes which were operating to produce the results, and valuable 

 indeed would be trustworthy observations along this line. Perhaps the dryness of the 

 season which prevented serious outbreaks of fungous diseases operated on behalf of the 

 infects ; perhaps the mildness of last winter enabled many more forms than usual to 

 pass through the dormant season ; perhaps parasites were not so numerous as usual ; but 

 whether there was one cause or a combination of causes the number of injurious insects 

 was on the increase during the past season. Mention will be made of a few of the most 

 injurious forms brought to the writer's attention chiefly by farmers and others in corres- 

 pondence with the Biological Department of the Ontario Agricultural College. 



Orchard Insects. 



The Fruit Bark-Beetle (Scolytus rugulosus). Complaints have reached us from 

 Kingevi-lle regarding the injuries done by this beetle. It attacks especially plum trees, 

 and many of Mr. J. D. Wigle's trees died from the injuries. It is probable that 

 trees in other sections are likewise affected, and watchfulness is required to prevent 

 surrounding trees from becoming infested. From breeding experiments carried on at the 

 College the writer finds that the adults appear about the middle of May. They 

 bore holes through the bark into the wood, and proceed to make burrows in which to 

 deposit egga. The young grubs also make burrows, and within a month the beetles 

 appear. Several broods may appear in a season so that the trunk soon becomes honey- 

 combed with tunnels and dies. See Fig. 3 (on page 35) which represents the work of an 

 allied species (S. destructor). 



