THE LITERARY 



OF THE LINN^AN ASSOCIATION OF PENNSYLVANIA COLLEGE. 



Vol. II. FEBRUARY, 1846. No. 4. 



THE NATURAL HISTORY OF LEPIDOPTEROU.S INSECTS. 

 From the French of Boisduval. 



The Larva^ or Caterpillar state. 



When tliey come forth from the egg^ the little caterpillars or larvae 

 are in their form more or less cylindrical and elongated ; their bodies are 

 composed of twelve segments or rings ; the head sliining and scaly ; 

 and the feet at least ten and at most sixteen in number. 



The head is formed by two different rounded and scaly caps, pre- 

 senting upon each side small, black points, projecting with greater or 

 less distinctness, like the eyelets, but apparently not serving for vision. 

 The mouth situated at its forepart, is very different from that of the per- 

 fect insect ; it resembles that of the insects called daubers ; it is com- 

 posed of two horny mandibles, more or less sharp according to the spe- 

 cies, two lateral jaws each having a very small palpus, a lower lip pro- 

 tected by two similar palpi, and a small cylindrical nipple perforated by 

 a little hole which has been called the spinneret (filiere, *) or fusus, 

 as it is from this that the threads of silk which the caterpillar spins, 

 issue. 



The body has along its sides, near the base of the legs, respiratory 

 openings, breathing-holes or siigmala. Nine have been counted upon 

 each side, one upon each ring, except the second, the third and the last, 

 which are destitute of them. These organs are of an oblongated form, 

 and resemble little button holes. They recur again in the perfect insect. 

 They are generally quite distinct, their color being different from the 

 ground color, though in some species ttiey cannot be seen without the 

 aid of a glass. The Jlglossa pinquinalis seems at first view to be des- 

 titute of them, but upon examination it is found that they are covered 



* I translate this word by the term employed by Kirby and Spence, though 

 the ideas which they convey are not the same.— Tr. 

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