the chapter on the control of insects gives information in 

 regard to many insecticide Bubstances with directions for 

 making various mixtures. 



The use of insecticides is explained, and descriptions are 

 given of the machinery and appliances adapted to their 

 application. 



The insects which attack growing crops may he 

 grouped in three main divisions, according to their manner 

 of feeding, or their habit of living. These are leaf-eating, 

 sucking, and boring. 



Leaf -eating insects are represented by a great variety of 

 caterpillars, beetles and grasshoppers, which with their 

 powerful mouth parts are able to bite off particles of the 

 plant, which they chew and swallow. Sucking insects are 

 those which have their mouth parts developed in such a 

 manner that they are able to puncture the tissues and suck 

 out the juices of the plant. They are represented by scale 

 insects, plant lice, white fly, cotton stainers, and bugs of 

 several kinds. Under this heading, also, might be included 

 thrips, red spider, leaf-blister mite, red maggot and flower- 

 bud maggot. The first two of these, thrips and red spider, 

 are intermediate in their feeding habits between the biting 

 and sucking types of insect, their mouth parts being adapt- 

 e 1 to enable them to gnaw away the surface of the tissue 

 where they feed : after this they obtain their food, probably 

 by a process of lapping, from the freshly exposed tissues. 

 The leaf-blister mite probably feeds in much the same way, 

 concealed among the plant hairs within the blister or gall 

 which is produced on the plant by the irritation due to its 

 activities. The flower-bud maggot and red maggot live in 

 nutritive tissue, and may absorb a certain amount through 

 the skin. 



Borino; insects are those which tunnel out for themselves 

 galleries within the tissues of plants. Their attacks are made 

 on the stem, the root, and the fruit of various plants. The 

 boring is generally done by such insects when they are in 

 the larval stage. Examples of this group of insects are 

 to be found in the moth borer and weevil borer of the sugar- 

 cane, the lime tree bark borer, the cacao borer, the palm 

 weevil and others which bore into the stems of plants ; the 

 root borer of sugar-cane, the scarabee of sweet potatoes and 

 others which bore into the roots. The minute larvae of 

 certain flies and moths live as miners in the leaves of plants, 

 forming galleries just beneath the epidermis. The mole 



