Leaf -eating Caterpillars Sugar Beet Webworm 



CHAPTER III 



LEAF FEEDERS 



Either because they feed exposed to the view of the most casual 

 observer or because their work is such as to attract general attention, 

 the leaf-feeding insects are much more universally known to the layman 

 than the root-feeding insects. In a general way the methods of controlling 

 this class of insects are common knowledge also. However, this knowl- 

 edge is of a superficial nature; that is, it is general instead of specific. 

 This lack of knowledge of the particular insect involved has led to much 

 waste of money, energy and material, either because the wrong remedy 

 has been applied or the right one was not applied in the correct way or 

 at the right time. 



A. BITING LEAF FEEDERS 



(Caterpillars, Beetles, Grasshoppers, Crickets, Leaf-miners) 



1. LEAF-EATING CATERPILLARS 



The young of moths or millers and butterflies are known by the 

 general name of caterpillars. In size, shape, color and body covering 

 they differ greatly in different species. 



Some are but a fraction of an inch in length, while others attain a 

 length of six or seven inches. For the most part caterpillars are cylindri- 

 cal, being several times as long as thick. Some are grub-like in form and 

 others resemble dead leaves or twigs in shape and color. The bodies of 

 many are bare, those of others are covered with long hairs. In some 

 species these hairs are connected with poison glands. If these cater- 

 pillars come in contact with the bare hands or face the sensation is very 

 similar to that caused by the sting of nettles, only more severe. Some 

 caterpillars are really formidable in appearance because their bodies are 

 covered with large .spines or spine covered tubercles. 



In the kinds of food eaten, caterpillars are as variable as in shape, 

 size or color. Some bore in the wood of trees, others feed upon hair, 

 wool, horn and like substances. A few feed upon scale insects and the 

 larvae of borers. Several species attack growing fruits, while others 

 destroy stored fruits and grains. The species with which we are most 

 concerned, and which are discussed in the following pages, feed upon the 

 leaves of plants. Among this class are to be found some of the worst 

 enemies of cultivated crops. 



(a) SUGAR BEET WEBWORM 



(Figs. 3, 4, 5, 6, 8, 9, 10, 1 1, Plate V, Page 19) 



The sugar beet webworm is one of the most destructive leaf-eating 

 insects attacking the sugar beet. Like many of our most injurious insect 

 pests, it was introduced into this country from the Eastern Hemisphere, 

 appearing first on the Pacific coast. In 1869 it damaged beets in Utah. 



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