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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...Ormerod, Miss. Manual of Injurious Insects. 2nd edition. 1890. Trail, Prof. James W. W. The Gall-making Hymenoptera of Scotland (exclusive of those that live on Oaks). 1888. 201 CHAPTER VI. COCCIDE (scale-insects). There is perhaps no class of insects more puzzling to the practical husbandman, the economic entomologist, or the biologist who is anxious to gain a general knowledge of insect structure and lifehistories, than the Coccidae or Scale-In sects. The student must rely almost entirely upon the microscope for the accurate determination of these insects, which from their minute size present exceptional difficulties. Even for general field-work it is necessary to have recourse to a strong pocket-lens; as to the naked eye, they may be confounded with lenticels--as, for example, those on birch-twigs. They may also be mistaken for certain micro-fungi on leaves or stems of various plants. In the Introduction it was emphatically asserted that concentration in the study of forest entomology was indispensable, inasmuch as almost every natural order was represented, and thus as a branch of forest science, to the forester in particular, general versatility in entomology was impossible. Scale-insects, however, are to some extent an exception to this rule. The arboreal-feeding species of this important family arc comparatively few, and therefore, in order to thoroughly understand the salient characteristics, it is necessary to glean information from all available sources. In other words, in order to thoroughly understand the special part, it is essential to make a general study of the available whole. But though the arboreal species in this country are comparatively few in numbers, the forester, or student of forest entomology, can always obtain an abundance of mat...

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