HEARING INSECTS. 249 



the larva undergoes,, which are often remarkable, especially 

 at the first moulting, with drawings illustrative of these; 

 the habits of the larva, whether solitary or gregarious, 

 whether a day or night feeder; the ichneumon parasites, 

 and their mode of attack. Specimens of larvas in the dif- 

 ferent moul tings should be preserved in alcohol. The ap- 

 pearance of the larvae when full-fed, the date, number of 

 days before pupating, the formation and description of the 

 cocoon, the duration of larvae in the cocoon before pupation, 

 their appearance just before changing, their appearance 

 while changing, and alcoholic specimens of larvae in the act, 

 should all be studied and noted. 



3. Date of pupation; description of the pupa or chrysalis; 

 duration of the pupa state, habits, etc. ; together with al- 

 coholic specimens or pinned dry ones. Lepidopterous pupae 

 should be looked for late in the summer, or in the fall and 

 spring, about the roots of trees, and kept moist in mould 

 until the imago appears. {Many Coleopterous pupae may 

 also occur in mould and, if aquatic, under submerged sticks 

 and stones, and those of borers under the bark of decaying 

 trees.) 



4. Date when the insect escapes from the pupa, and 

 method of escape; duration of life of the imago; and the 

 number of broods in a season. 



Drawing Caterpillars. After some practice any one can 

 make a recognizable drawing of even an insect, especially of 

 a caterpillar, and after a little experience even a sketch in 

 water-colors. Drawing in natural history is all-important 

 to the beginner; it trains the eye to observe closely, and 

 good sketches of the early stages of insects are especially 

 needed in this country. Various cameras have been contrived 

 to enable the artist to get a correct outline of objects, while 

 for flat, microscopic objects the use of the camera lucida is 

 invaluable; after a few trials it can be used both for draw- 

 ing outlines and filling in details. In this way the larvae 

 of the Micro-lepidoptera mounted on glass slides may be 

 drawn. 



