Entomology for beginners; for the use of young folks, fruitgrowers, farmers, and gardeners; . nging, the body of the caterpillar becomesshorter and thicker, and remains so for one or several days;that of the saw-fly remains in this state through the this period, called the semipupal stage, the pupadevelops, its skin separating from that of the larva. It should be borne in mind that the skin is composed of two layers; the under oneformed of cells and called thehypodermis (Fig. 37), whichsecretes the hard, chitinous,structureless outer layer orcrust. The hypodermis ofthe growing pu
Entomology for beginners; for the use of young folks, fruitgrowers, farmers, and gardeners; . nging, the body of the caterpillar becomesshorter and thicker, and remains so for one or several days;that of the saw-fly remains in this state through the this period, called the semipupal stage, the pupadevelops, its skin separating from that of the larva. It should be borne in mind that the skin is composed of two layers; the under oneformed of cells and called thehypodermis (Fig. 37), whichsecretes the hard, chitinous,structureless outer layer orcrust. The hypodermis ofthe growing pupa tends moreand more to assume the shape FIG. 37. — Cross section through the .p 11 „„ „„,] ,p T^iioplpo cuticula, C, and hypodermis, M. The 01 tne PUP% andsetae or hairs,//, are articulated at nvi,q nflmv nrrrona witliinC with the cuticula; HZ, cell. The antt poison-glands at the base of the cliar,ore their shape, Untilbristles of some insects Judeich and Nitsche. finally the old larval skill rup- tures along the back, and the pupa slips out of the PARTHENOGENESIS. 41 • The pupae of different insects vary greatly in form. Inthe insects with an incomplete metamorphosis the pupaonly differs from the larva in having pad-like rudimentarywings. In such insects development is direct, and properlyspeaking they pass through no true larval or pupal , some authors with good reason apply the termni/mph to the early stages of Orthoptera, white ants, may-flies, dragon-flies, etc.; this term embracing what is usuallycalled the larval and pupal states of those insects, as duringthese periods they are active and take food. The Imago.—This is the final or adult state, when thewings are developed and the insect is able to fly aboutand lay its eggs. As soon as insects, such as moths orbutterflies, wasps or bees, have completed their transforma-tions they pair, and the females seek a suitable place todeposit their eggs. After this act is a
Size: 1945px × 1284px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookpublishe, booksubjectinsects
