APPENDIX II
THE LEPIDOPTERIST'S CALENDAR
The success of the country rambles of an expert lepidopterist depends greatly on his knowledge of the times at which the various butterflies and moths generally appear, and of the localities which they are known to frequent. The experiences he has gained in the past enable him to calculate on the probabilities of the future, and he chooses both time and locality according to his requirements.
As he makes his way to the hunting ground he counts over the chances of meeting with a certain insect that is wanted to fill a long-standing blank in his cabinet; and we hear him discussing the probabilities as to whether this species is yet 'out,' or whether the larvæ of that species are feeding.
How different it is with the young and unguided entomologist! He rambles promiscuously here and there, having only the faintest idea as to what he is likely to see, and perhaps meeting with only four or five species when an experienced collector, without covering a larger area of ground, would take scores in the same time.
In order to afford some little help to the beginner, I have thought it advisable to introduce a calendar of operations to guide him in his work. The space at our command would not allow this to be carried out in detail, but the general instructions will undoubtedly assist most of my readers until the practical experience gained by a few years' work has enabled them to run on their own legs.
Of course, in making reference to the monthly lists of insects on the wing, allowance must be made for the forwardness or backwardness of the seasons. Thus, an insect entered in the April list may appear in March in an exceptionally warm season, but may not emerge till the early part of May if the spring has been unusually severe.
It will be observed that in cases where all the species of a certain genus or family appear on the wing in the same month, the name of that genus or family is entered on the list instead of the names of the individual species; but the latter can easily be obtained by reference to [Appendix I].
JANUARY
There is not much field work to be done during this month. If the weather is very severe, hardly an insect will be found on the wing; but a mild January will sometimes entice the Brimstone Butterfly (Rhamni) and some of the hybernating Vanessas from their winter quarters.