BREEDING LARVAE. 33 



their life. At the approach of cold weather, the breeding 

 cage should be removed to the cellar and kept there until 

 spring. The collector in his trips through the woods and 

 fields will find many pupae ; these should be brought home 

 and placed in the breeding cage and the imago obtained. 

 This method of breeding insects in confinement has many 

 advantages, the most prominent being that the images ob- 

 tained are perfect and not in that rubbed condition which is 

 frequent in those caught with the net. 



Occasionally, a larva will fail to go through its proper 

 changes. This is generally caused by the presence of some 

 parasite. The most common of these parasites are Ichneu- 

 mon larvae. The adult ichneumon stings the larva and lays 

 its eggs ; these hatch and the progeny live on the juices and 

 tissues of its host until at last it succumbs, and then the para- 

 sites go through their changes and finally emerge as perfect 

 insects. These ichneumon flies should be carefully preserved 

 with full notes of the host, etc. 



Spiders and Myriapods may be found everywhere and are 

 best preserved in spirit. With spiders should be preserved 

 careful notes of colors, and the form of the web, whether 

 vertical or horizontal, flat or dome shaped, etc. Especial 

 pains should be taken to collect the male which is much 

 smaller than the female and is frequently found with it. The 

 two cannot be kept together alive as the female is so fond 

 of her mate that she frequently eats him. Myriapods are 

 rather difficult to preserve, because their integument is so 

 thick that the alcohol does not readily penetrate and therefore 

 the tissues of the body decay and the specimen falls to pieces. 

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