[115] COLLECTING AND PEESERVING INSECTS RILEY. 



Detailed Instructions for Rearing. — Iii the rearing of insects every 

 worker will develop a number of methods of value, and it is only by 

 careful study and comparison of the experiences of all that the best 

 system can be elaborated. For this reason I have, in what follows, 

 quoted, in a more or less fragmentary way, the experiences of different 

 entomologists. 



As is remarked by Miss Murtfeldt, in an interesting paper read before 

 the Entomological Club of the American Association for the Advance- 

 ment of Science, August 20, 1890, " there is a great individuality, or 

 rather speciflcahty, in insects, and not infrequently specimens of larvse 

 are found for which the collector taxes his ingenuity in vain to provide. 

 Not the freshest leaves, the cleanest swept earth, or the most well-aired 

 cages will seem to promote their development." 



The greatest care and watchfulness, therefore, are necessary to insure 

 success in the rearing of larvae. In many cases such larvae can only be 

 successfully reared by inclosing them in netting on their food-i^lant out 

 of doors. It is a frequent device of Lepidopterists also to inclose a 

 rare female in netting placed on the food plant of the species, where 

 the male may be attracted and may be caught and placed in the bag 

 with the female, when copulation usually takes place successfully, or a 

 male may be caught in the field and inclosed with such female. Mr. W. 

 H. Edwards, where the plant is a small one, uses for this purpose a 

 headless keg covered at one end with gauze, which he places over the 

 XDlant inclosing the female. 



Mr. James Fletcher, of Ottawa, Canada, one of our most enthusiastic 

 rearers of insects, has given some details of his methods in a recent 

 very interesting account of "A Trip to Nepigon." One style of cage 

 used by him in securing the eggs of large Lepidoptera " is made by cut- 

 ting two flexible twigs from the willow or any other shrub and bending 

 them into the shape of two arches, which are put one over the other at 

 right angles and the ends pushed into the ground. Over the pent- 

 house thus formed a piece of gauze is placed, and the cage is complete. 

 The edges of the gauze may be kept down either with pegs or with 

 earth placed upon them." This kind of cage is used for all the larger 

 species which lay upon low plants. The sj)ecies which oviposit on larger 

 plants or trees are inclosed in a gauze bag tied over the branch. This is 

 applicable to insects like Papilio, Limenitis, Grapta, etc. Care must be 

 taken, however, that the leaves of the plant inside the net are in a nat- 

 ural position, for some species are very particular about where they lay 

 their eggs, some ovipositmg on the top of the leaves, others near the 

 tip, and many others on the under surface. " When a bag made before- 

 hand is used, the points must be rounded, and in tying the piece of 

 gauze over the branch care must be taken to pull out all creases and 

 folds, or the insect will be sure to get into them and either die or be 

 killed by spiders from the outside of the bag. It is better to put more 

 than one female in the same cage. I have frequently noticed that one 



