102 



THE REPORT OF THE 



No. 19 



The day is fast approaching when the successful fruit-grower will not dare to neplect the 

 study of insects. He must know, or recognize, the authors of the injuries done to his trees 

 and shrubs, if he ever hopes to get the largest returns for his investment. 



In the following Key to Orchard Insects an attempt is made to group the insects according 

 to (1) the host-plant attacked ; (2) the particular part or parts oi the host-plant attacked ; 

 (3) the character of the injuries ; and (4) in some instances, the most peculiar characteristic 

 habits. Insects are known by their work. Every insect has its own peculiar mode of working, 

 and when the injurious insect is once recognized and its habits known, it is usually not difficult 

 to follow a line of treatment which will be successful. 



Remedies are not given here. They may be found in the Spray Calendar, (Bulletin 122), 

 published by the Department of Agriculture, Toronto. 



From the stand-point of the fruit-grower, the mouth-parts of insects are the most important 

 portions of their anatomy. Consequently, a special study should be made of these parts. The 

 young and adults of beetles, grasshoppers, and crickets have biting mouth-parts, hence they 

 can usually be readily killed by the application of Paris Green, or some other poisonous sub- 

 stance to their food. The adults of butterflies and moths have sucking mouth-parts, hence 

 cannot be killed by poisons. These, however, are not usually injurious. The young forms of 

 these, known as caterpillars, have biting mouth-parts, hence they can be poisoned. Both the 

 young and adult forms of bugs and plant lice have sucking mouth-parts, hence they must 

 be treated with powders, liquids or gases that kill by contact or suffocation. 



It is also of importance that the fruit-grower learn to recognize the larvse, for they are 

 usually the most injurious stage of insect life. The young of moths and butterflies, usually 

 called caterpillars, are in most cases 16-legged, with the exception of the loopefs which are 

 10-legged. The grubs or worms of saw-flies are 20-legged. The young of beetles, or grubs, 

 are usually 6-legged. The maggots of flies, bees and wasps are usually legless. The young 

 of grasshoppers, bugs and plant-lice are 6-legged, and resemble more or less the adult forms. 



In the preparation of this Key, the writer received valuable aid and suggestions from the 

 writings of Dr. A. D. Hopkins, of West Virginia ; Prof. L. Bruner, of Nebraska ; Dr. W. 

 Saunders, of Ottawa ; and Dr. Bethune, of London. 



Key to Apple Insects. 

 Attacking the Roots : 



1. Causing knots or swellings on the smaller roots — bluish-white mouldy lice. 

 Woolly Aphis (Schizoneura lanigera). Fig. 64. 



Fig. 04. Woolly Aphis. 



Fig-, db. Oystei-shell Bark-louse. 



B. Attacking tlie Trunk, Branches, a')ul Twigs: 



1. Producing longitudinal slits in the bark ; eggs under the edges of the slits. 

 Buffalo Tree-hopper (Ceresa bubalus). See Fig. 7» 



