20 OUTLINES OF ENTOMOLOGY. 



In the pupa state most insects are quiescent and apparently life- 

 less, and while it continues are incapable of taking food or performing 

 any of the active functions of life. Pupae that are enclosed in cocoons 

 or cells are termed folliculate. A pupa destined to give forth a butter- 

 fly is designated a chrysalis, from a Greek word meaning golden, in 

 reference to the gilded ornamentation of many chrysalides. 



There are two forms of quiescent pupae, the oUeeted and the 

 coarctate. In the first mentioned form the legs, wings and antennae of 

 the future imago are shown, each enclosed in a separate sheath. The 

 pupae of bees, wasps, beetles, etc., are obtected. In coarctate pupae a 

 continuous shell encloses the members as well as the body of the 

 insect. 



The pupae of insects not subject to complete metamorphosis are 

 active, and do not differ much either in form or habit from the full- 

 grown larvae, except in the greater development of the rudimentary 

 wings. 



After a certain time, varying with the nature of the insect and with 

 the season of the year, the second transformation takes place and the 

 insect issues from the pupa shell in its mature or perfect form. 



In this stage of its existence it is, with a few exceptions, charac- 

 terized by the possession of fully developed wings. It has also large, 

 compound eyes, conspicuous antennae and various other organs which 

 did not appear in its preceding forms.. The head, thorax and abdomen 

 are now well-defined regions, and the sexes can usually be distinguished 

 with ease. In most species the females are larger than the males, and 

 the latter, besides being more slender in body, ar'e often more gaily 

 colored and have the antennae longer or more ornamental than those of 

 the female. 



The abdomen of the female is furnished with an ingenious instru- 

 ment called an ovipositor, through which the eggs are conducted to 

 such situations as will be most favorable to the future larvae. It serves 

 not only to place the eggs, but is used by many insects to drill holes or 

 saw slits or otherwise prepare suitable receptacles for them. In such 

 species the ovipositor is usually a very conspicuous appendage. In 

 others it is, when not in use, drawn entirely within the body. 



As previously remarked, after insects have acquired their wings 

 they never grow. Thus the idea that little flies or gnats develop into 

 "house-flies" or "blue-bottles," as some people suppose, or that little 

 beetles or bugs or butterflies ever grow to be large beetles or bugs or 

 butterflies, is seen to be entirely erroneous. 



Since perfect insects do not grow, it follows that they require but 

 little food ; some are incapable of taking even a sip of dew or nectar. 



