. Elements of comparative zoology. Zoology. 250 SYSTEMATIC ZOOLOGY. ORDER V.—COLEOPTERA. The beetles are all grouped under the common head of Coleoptera, the name of which means sheath-wings. Of beetles there are known over a hundred thousand different kinds, but all these agree in the following points: The mouth-parts are fitted for biting; ocelli rarely occur; the pro thorax is large; the anterior wings are converted into thick, horny wing-covers or elytra, beneath which are folded the much larger hinder wings. From the egg of the beetle there hatches out a some- what worm-like form popularl
. Elements of comparative zoology. Zoology. 250 SYSTEMATIC ZOOLOGY. ORDER V.—COLEOPTERA. The beetles are all grouped under the common head of Coleoptera, the name of which means sheath-wings. Of beetles there are known over a hundred thousand different kinds, but all these agree in the following points: The mouth-parts are fitted for biting; ocelli rarely occur; the pro thorax is large; the anterior wings are converted into thick, horny wing-covers or elytra, beneath which are folded the much larger hinder wings. From the egg of the beetle there hatches out a some- what worm-like form popularly known as a 'grub/ This larva (fig. 67; b), as it is called, bears but the slightest re- semblance to its parents. It eats and grows, without essentially altering its appearance until at last it under- goes a molt which results in a sudden change in its appear- ance. It is no longer wrorm-like, but looks more like the adult beetle. This stage, the pupa (fig. 67, c), does not eat, but lies quiet in some cavity; after a longer or shorter period of rest it molts again and emerges the perfect beetle, after which, no matter how long it may live, it under- goes no further changes nor does it increase in size. In other words the beetles are holometab- olous and, together with the Lepidop- tera, afford the best-known examples of a complete metamorphosis. The beetles are divided into two great groups. In the one (Rhynchophora) that part of the head which bears the mouth is prolonged into a snout; in the other there is no such prolongation. These are called the normal Coleoptera. The snout beetles (RHYNCHOPHORA) or true weevils are all injurious, since as larvae and adults. FIG. 74. - - Hazel- nut-weevil (Ba- laninus nasicus).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Kingsley, J. S. (John Sterling), 1854-19
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1904
