A treatise on some of the insects of New England which are injurious to vegetation / by Thaddeus William Harris.

  • Harris, Thaddeus William, 1795-1856.
Date:
1852
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on some of the insects of New England which are injurious to vegetation / by Thaddeus William Harris. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    therein its future form is more or less masked or concealed. This name is not only applied to grubs, caterpillars, and maggots, and to other insects that undergo a complete trans- formation, but also to young and wingless grasshoppers, and bugs, and indeed to all young insects before the wings begin to appear. In this first period, which is generally much the longest, insects are always wingless, pass most of their time in eating, grow rapidly, and usually cast off their skins repeatedly. The second period, wherein those insects that undergo a partial transformation, retain their activity and their appetites for food, continue to grow, and acquire the rudiments of wings, while others, at this age, entirely lose then- larva form, take no food, and remain at rest in a deathlike sleep,—is called the pupa state, from a slight resemblance that some of the latter present to an infant trussed in bandages, as was the fashion among the Romans. The pupae from caterpillars, however, are more commonly called chrysalids, because some of them, as the name implies, are gilt or adorned with golden spots; and grubs, after their first transformation, are often named nymphs, for what reason does not appear. At the end of the second period, insects again shed their skins, and come forth fully grown, and (with few exceptions) provided with wings. They thus enter upon their last or adult state, wherein they no longer increase in size, and during which they provide for a continuation of their kind. This period usually lasts only a short time, for most insects die immediately after their eggs are laid. Bees wasps, and ants, however, which live in society, and labor together for the common good of their communities, continue much longer in the adult state. In winged or adult insects, two of the transverse incisions with which they are marked, are deeper than the rest, so that the body seems to consist of three principal portions the first whereof is the head, the second or middle portion the thorax or chest, and the third or hindmost the abdomen, or hind-body. In some wingless insects these three portions are also to be seen; but in most young insects, or lame, the body consists of the head, and a series of twelve rings or segments, the thorax not being distinctly separated from the hinder part of the body, as may be perceived in caterpillars, grubs, and maggots. /■