344 LEPIDOPTERA. 



perfect, fresh, and uninjured moths from thom. In this wa}' 

 many species never found in the perfect state can be secured.* 

 In raising ^'■'iuicro" larvae it is essential that the leaf in 

 which they mine be preserved fresh for a long time. Thus 

 a glass jar, tumbler or jam-pot, the top of which has been 

 ground to receive an air-tight glass cover, and the bottom 

 covered with moist white sand, will keep a leaf fresh for a 

 week, and thus a larva in the summer will have to be fed but 

 two or three times before it changes ; and the moth can be 

 seen through the glass without taking off the cover ; or a glass 

 cylinder can be placed over a plant inserted in wet sand, hav- 

 ing the top covered with gauze. Dr. H. G. Knaggs in treat- 

 ing of the management of caterpillars in breeding boxes, 

 enumerates the diseases, beside muscardine and cholerine, to 

 which the}^ are subject. Among direct injuries are wounds and 

 bruises, which may be productive of deformities in the future 

 imago ; the stings of ichneumon flies, whose eggs laid either 

 upon or in the body may be crushed with finely pointed scis- 

 sors or pliers ; frost bites, and suffocation chiefly from drown- 

 ing. If the cateriDillar has not been more than ten or twelve 

 hours in the water it may be recovered by being dried on a 

 piece of blotting paper and exposed to the sun. Larvse may 

 also starve to death even when food is abundant, from loss of 

 appetite, or improper ventilation, light, etc. ; or thej' may eat 

 too much, become dropsical, and die. Caterpillars undoubt- 

 edly suffer from a contagious disease analogous to low fever. 

 Many die while moulting, especially the larvse of Butterflies, 

 Sphinges, and Bombycids ; others are carried off by diarrhoea, 

 which is generally caused by improper feeding on too juicy or 

 relaxing food, when oak leaves or dry stunted foliage should 

 be given them. To relieve constipation thej should be fed 

 with lettuce and other natural purgatives, and lastly, thej^ may 

 be attacked by fungi, especially, besides those previously men- 



*" In general, it may be said, the mines of the leaf miners are characteristic of 

 the genus to which the larva may belong. A single mine once identified, enables 

 the collector to Yjronovmce on the genus of all the species he may find thereafter. 

 This added to the ease with which the larva; are collected, and the little subsequent 

 care required to bring them to maturity, except to keep tlie leaves in a ft-esh and 

 healthy state, makes the study of this group, in evei-y respect, pleasant and satis- 

 factoiy to the entomologist." (Clemens.) 



