The Insect World - Paperback

THE INSECT WORLD BEING A Popular Accoztnt of the Orders of I tsects TOGETHER WITH A DESCRIPTION OF THE HABITS AND ECONOhlY OF SOME OF THE MOST INTERESTING SPECIES WITH - 1872 - C O N T E N T S - INTRODUCTION . APTERA . DIPTERA . Nemocera . Brachycera . HE IPTERA . Heteroptera . Hornoptera . LEPIDOPTERA . The Larva, or Caterpillar The Chryszlis, or Pupa The Perfect Insect . ORTHOPTERA . HY ENOPTERA . THYSANOPTERA . NEUROPTERA . COLEOPTERA . INDEX . - PAGE . . . I 27 33 35 . 47 . 90 9 0 . I01 . 138 . 138 . 146 . 165 .. 284 313 400 l . 402 435 523 - INTRODUCTION - IT is not intended to investigate the anatomy of insects in this work thoroughly but, as we are about to treat of the habits and economy of certain created beings, it is necessary first to explain the principal parts of their structure, and the stages which every perfect insect or imago has undergone before arriving at that state. We, therefore, proceed to explain, as simply as possible, the anatomy of an insect, and the functions of its organs. If we take an insect, and turn it over, and examine it carefully, the first thing that strikes us is that it is divided into three parts the head the thorax, or chest and the abdomen, or stomach. The head Fig. I is a kind of box, formed of a single piece, having here ant1 there joints more or less strongly marked, sometimes scarcely visible. It is furnished in front with an opening-often very small-which is the mouth and with some for the eyes, and with others for the insertion of the antennE or horns. The integuments of the head are generally harder than the other parts of the body. It is necessary that this should be so. Insects often live and die in the midst of substances which offersome resistance. It is necessary, therefore, that the head should be strong Fig. l.-Head of an Insect. enough to overcome such resistance. The head contains the masticatory organs, which, frequently having to attack hard substances, must be strongly supported. The exception to this rule is among insects which live by suction. It would be out of place here to mention the numerous modifi-1 . cations of the head which are presented in the immense class of insects. The eyes of insects are of two kinds. There are compound eyes, or eyes composed of many lenses, united by their margins and forming hexagonal facettes and there are also simple eyes, or ocelli. The exterior of the eye is called the cornea Fig. 2, each facette being a cornea and the facettes, which vary in size even in the same eye, unite and form a coinmon g. Compound cornea, which is represented by the entire figure. In order to show the immense number of the facettes possessed by many insects, we give the following list -In the genus Mordclla a genus of beetles the eye has 25,008 facettes. In the LibcZluZa dragon-fly . 12,544, , In the genus Papilb a genus of butterflies . 17,355 9, In Sphinx convolvuli the convolvulus hawk-moth . 1,300, In Bombyx mori the common silkwonn moth . 6,236 ., In the house-fly . 4,000 -, In the ant . 50, , In the cockchafer . ...