44 • N.S. ENTOMOLOGICAL SOCIETY. 



air supply is also very small. It would seem from these facts that the pupae are better 

 fitted to show relationships than either larvae or adults. 



Aside from any scientific interest connected with the study of pupae there is still a 

 great deal of pleasure to be gained from rearing them. It is fascinating to watch the 

 preparation of the larva for pupation especially in the case of those forrr\s which spin a 

 cocoon. There are many unique ways of concealing the cocoon and in the case of a 

 species whose life history is unknown it is impossible to determine just where the pupa 

 will be formed. As far as our knowledge of classification goes, we do not always find 

 closely related species pupating in the same situation. There are large groups of in- 

 sects where one expects pupation to take place in the soil and this invariably happens. 

 There are other groups which always spin cocoons of a certain type; still others which 

 suspend the pupa in a peculiar fashion. Scudder was of the opinion that this indicated 

 relationship, but just how far this is true is as yet unknown. The peculiar forms as- 

 sumed by pupae form an intensely interesting story, and although comparatively few 

 show coloring, other than the dull or glistening white of so many Coleoptera, Diptera, 

 Hymenoptera and some Lepidoptera, or the reddish brown common to the majority 

 of the remainder, including most of the Lepidoptera, this phase of the subject is always 

 worthy of consideration. 



It should be urged upon every collector in the Province to preserve, as far as pos- 

 sible, the immature stages of all bred material. The first collectors in America paid no 

 attention to anything but adults. Gradually it became necessary to have the larvae 

 of certain insects for study, particularly where these were of economic importance, so 

 that collections of these are gradually increasing in the country. The pupa is the last to 

 receive attention at the collector's hands, and there are very few specimens in exist- 

 ence, compared with the mass of other entomological material. Pinned pupae do not 

 furnish good subjects for study, but, if pinned the pin should pass diagonally from one 

 side of the body to the other, and not dorso-ventrally on the median line, as is so often 

 done. Specimens for study should be killed in 95 per cent alcohol and allowed to re- 

 main for a few minutes after death in the case of hard pupae, or one to three hours in 

 the case of soft ones. They are then transferred permanently to 70 per cent alcohol. 

 Alcohol of greater strength than this distorts the parts of the softer kinds. Since this 

 war has taught us the felly of making ether people's mistakes, let us obtain all the evid- 

 ence we can about the life histories of insects, and then preserve all the evidence. 



THE ZEBRA CATERPILLER. 



Ce i arnica picta Harris.) 



H. G. Payne. 



IN VIEW of the fact that the zebra caterpillar has been a serious pest for the past 

 few seasons, it seemed advisable to study the life history with as much detail as possible; 

 the following paper is the result of these investigations. 



LIFE HISTORY. 



Towards the end of June and early in July the adult moths emerged from the pu- 

 pae in their earthen cells and in a few days the females laid their eggs upon both sur- 

 faces of the leaves of turnips, beets, mangolds, beans, small shrubs and even apple 

 trees. The eggs hatched five or six days later and the young caterpillars commenced 

 feeding first upon their empty egg shells and then upon the host plant, eating the sur- 

 face of the leaves only. When young they were strongly gregarious but later they se- 

 parated and might be found singly or two or three together. This first generation be- 



