Iktroduction. xIv 



journals and notf,-b00ks. 



We have already said that rearing Lepidoptera is important as a means by which we may 

 obtain an insight into their life-history and habits. But for this purpose it is necessary to be 

 quite sure which insect is the perfect state of each larva, as well as to record our observations 

 on the larva and its habits in writing. For this purpose a journal must be kept, in which every- 

 thing of importance should be noted at the time, especially the change in the larva at each moult, 

 and any circumstances which will make our observations reliable, and prevent our falling into 

 mistakes and confusing one larva with another. The following hints may be useful. 



Each larva or pupa cage may be designated by a certain number, and all larvae with the 

 natural history of which we are not fully acquainted, or from which we do not know what insect 

 will result, should be kept separate. The pupae obtained from such larvae should also be kept 

 separate, if possible ; and if not, they should be put into a particular part of the pupa-cage and 

 marked with a separate number. 



Then we must note in the journal the number of the breeding-cage in which the larva, and 

 subsequently the pupa, is placed, as well as the number of the pupa, the day, the locality, and the 

 plant where the larva was found, the dates when it moulted and when it became a pupa, as 

 well as the date of the appearance of the perfect insect. Besides this, a precise description must 

 be made of all unknown larvs, and of all those which do not exactly agree with a description 

 or figure before us. Larvre which alter their appearance after moulting must be carefully 

 described in each stage. If the collector can draw, a careful drawing of the larva would also 

 be very desirable. When we think we recognise a larva from a figure or description, this may also 

 be referred to in the journal. When the perfect insect appears, its name should be added to the 

 description of the larva. 



The diary can be best kept in a quarto manuscript book, ruled with columns for the number 

 and name of the larva and pupa, descriptions and citations, locality, food-plant, moultings, 

 dates of the larva becoming a pupa and of the appearance of the perfect insect, and remarks. 

 It will, however, save much space to have a separate book for detailed descriptions, and keep 

 the first for dates and short memoranda, as aforesaid. All larvae which the collector has not 

 already bred should be entered in this journal, but he need not enter those with which he is 

 already fully acquainted, except when they do not agree with his former observations respecting 

 food-plant, times of appearance, &c. 



It is very desirable that the journal should also contain observations on the state of the 

 weather, especially the temperature, the forwardness or backwardness of the season, &c. All 

 these conditions influence the times of appearance of larvae and perfect insects, and the different 

 observations will in time be useful to form a table, according to which the appearance of certain 

 insects can be definitely expected at a certain time every year, according to the weather. 

 Nothing has yet been done to compare the times of appearance of the same species in different 

 parts of Europe, which often differ very much. Such entries, however, could be more conveniently 

 entered in an ordinary diary than in the journal of which we have been speaking. The nature 

 of the season, whether forward or otherwise, and the progress of vegetation on which insect life 

 depends, may be indicated by noting the date at which common and well-known plants are 

 observed in blossom, such as the wood-anemone, the starwort, the gooseberry, the lilac, the 

 apple, the blackthorn, the hawthorn, the sallows, the heaths, &c. The average temperature, 

 as well as the highest and lowest on each day, the number of sunny and rainy days, and the 

 direction of the wind, should also be noticed. 

 /13 



