INSTRUCTIONS FOR COLLECTING INSECTS. 183 



ever, no certain mode of distinguishing but by experience, for the 

 oldest collectors are sometimes deceived. Many caterpillars hyber- 

 nate during winter, and may be found concealed under stones, &c. 

 ■when the cold weather of autumn approaches, or are dug up at the 

 roots of trees during search for pupa3. They should never be kept in 

 a warmed room, but exposed as soon as taken to the temperature of 

 the external atmosphere. And lastly, we must not forget to mention 

 that a number of species inhabit the water plants, growing in quiet 

 X)ools and on the margins of little lakes. 



With regard to the means of collecting specimens, the student 

 should supply himself with a number of pill-boxes of various sizes, in 

 which to carry his captures when found, remembering that some of 

 them are carnivorous, and will make a meal of their companions 

 when forced into intimate association. He must note particularly the 

 plant on which the larva has been found, and put a portion of it in 

 the box, and remember that in general tliey will eat of nothing but 

 the species of 'plant on which they loere found. Hence it is almost im- 

 possible to rear a larva which has been met with under conditions 

 that give us no information respecting its natural food plant, unless 

 by trying it with a variety we at last accidentally find one it will eat. 



He should carry an umbrella, and by beating bushes and the 

 branches of trees into it with a cane or rod, it will receive the dis- 

 lodged larvae, and save him the trouble of search. Or several yards 

 of white cotton sheeting may be spread beneath a tree, and the upper 

 branches above it beaten with a pole, when we have reason to suspect 

 the presence of larvae. An ardent collector, living in a little village 

 in this vicinity, carries with him during his excursions a stout rope 

 and hatchet. If, in examining the ground beneath forest trees, he 

 finds fresh " frass" from the larger caterpillars, he scans the branches 

 until lie detects the eaten leaves, and then, casting his rope over a 

 stout limb by means of a stone^ he ascends the tree rapidly, severs 

 with his hatchet the branch on which he supposes the larvae to be, 

 and, descending, secures his well-earned prize. In this manner he 

 has irequently collected on the hickory during one day twenty larvae 

 of the rare and heaMiUxAlDnjocampa imperialis. 



When leaves are unrolled to ascertain if a larva is present, it should 

 always be done over a spread handkerchief^ as otherwise the disturbed 

 inhabitant may make its escape by falling to the ground. All falling 

 larvae, however, attach their thread previously to deserting their food 

 plant, and can usually be found, if they have reached the ground, by 

 passing the hand beneath the place where it was, when it will come 

 in contact with the thread, and this will serve as a guide to find it 

 again. The mines of leaf miners should not be opened to ascertain 

 whether they contain an inhabitant ; this information can be obtained 

 by holding the leaf between the light and the eye. 



The collector will sometimes find the egg of some species of ichneu- 

 mon attached to the skin of the larvae. We do not mean the cocoon 

 of the larva of a small ichneumon, so frequently mistaken for eggs by 

 the uninitiated, but veritable eggs, which, if permitted to remain, pro- 

 duce larvae that will destroy the pupa. This is very easily prevented 

 by crushing the eggs with a pair of fine-pointed pincers, being careful 



