1921 ENTOMOLOGICAL SOCIETY. 37 



Pistol Case-beaker (Coleophora malivorella). This insect is usually unim- 

 portant in Ontario, especially in the colder parts, being much less abundant than 

 the Cigar Case-Bearer. This year, however, it was very prevalent on apple 

 foliage at Newcastle. 



The Oak Leaf-bug (Lygus quercalbae). This mirid, which normally breeds 

 and feeds on oak, attacked the fruit of peaches in late June at St. Davids, and 

 rendered a large percentage unfit for sale. Only orchards close to oak trees were 

 affected. 



The iMullein Plant Bug (Campylo;nima verb as ci) . This small plant bug 

 was again found attacking apples in two large orchards at Simcoe.. It was present 

 however, in comparatively small numbers, and caused no serious injury. 



The Pear Psiylla (Psylla pyrieola). The cool summer and the comparative 

 scarcity of insect enemies were apparently very favorable for the development 

 of this insect and it became unusually abundant in the Niagara, Burlington, 

 Bowmanville and Newcastle districts. At Burlington practically all the Bartlett 

 pears were stained by "the honey-dew fungus to such an extent that they had to 

 be washed before the buyers would accept them. The psylla was very scarce at 

 Guelph. 



The Pear and Cherry .Slug (Eriommpoides limacwa). We are glad to 

 report that tin's insect, which was so destructive in 1918-19, was comparatively 

 scarce this year. In a few neglected cherry orchards some trees were partially 

 defoliated, but in most fruit sections the slug caused no appreciable damage. 



Green Fruit Worms (Graptolitha sp.). A species of Graptolitha was quite 

 abundant on peaches in the Vineland district. However, on account of the abund- 

 ance of fruit the loss caused by this insect was not felt after the injured peaches had 

 been thinned out. 



Peach Tree Borer (Sanninoidea exitiosa). According to complaints 

 received from growers, and reports from the Provincial Inspector and his staff, 

 this borer was responsible for more injury than usual in the Niagara district. 



Fruit-tree Bark-beetle (Eccoptog aster rugulosus). Several complaints of 

 bark-beetle injury to peach trees were received from the Niagara district and 

 Kent county. 



Pose Ci-iaeer (Macrodactyhis subspinosus) . Local outbreaks of this pest 

 occurred at Simcoe, St. Catharines and Fenwick. Grapes, peaches, apples and 

 other plants were attacked iand in some cases seriously injured. 



Black Cherry .Aphis (Mysus cerasi). This plant louse was very abundant 

 on, and injurious to sweet cherry trees in the Niagara fruit belt. 



Plum Spider-mite (Tetranyclius pilosus). In the Niagara district plum 

 trees, unsprayed or sprayed with Bordeaux mixture, were heavily infested by 

 this species. On badly attacked trees the mite not only made the foliage pallid 

 and sickly in- appearance, and checked the growth of the trees, but it also dwarfed 

 the fruit and retarded its ripening. 



By weighing and measuring lots of plums from infested and uninfested 

 trees we secured the following data: 



Loss of weight due to mite infestation — Gueii 41.5%, Pond Seedling 20.6%, 

 Lombard 27.3%, Peine Claude 28.7%. 



Loss in size— Gueii 40.3%, Pond Seedling 24.3%, Lombard 19.1%, Peine 

 Claude 24.8%. 



Our experiments this year proved again that this pest can readily be con- 

 trolled by spraying with Lime Sulphur. 



