Butterflies and Moths (British)

by William S. Furneaux

For such out-door work in search of moths a good lantern is essential. An ordinary 'bull's-eye' is almost useless, for, although it concentrates a good light on certain objects, the narrow range of its rays constitutes a strong objection to its use for entomological work. For this purpose it is necessary that the rays of light not only pass in front of you, but also shoot off right and left to warn you of the approach of a moth before it is too late to wield the net. This wide range may be obtained by means of three flat glass sides, or, better still, by a bent plate glass front.

In addition to this you must go out provided with your net, killing bottle, and a number of pill boxes. Choose your night according to the hints already given, and if you are on the look-out for any particular species, be careful that the date of your outing is well timed, making any necessary allowances for the forwardness or backwardness of the season, for a moth that is generally due on a certain average time of the year may appear some weeks sooner if the preceding weeks have been unusually warm, or its emergence may be delayed considerably by the prevalence of cold east winds or a late frost.

Make up your mind as to the field of your operations before you start, and if possible choose a route that will carry you through a variety of situations, so that you may pass the favourite haunts of a number of different species. Clearings in woods with an abundant undergrowth, waste places with plenty of tall and rank vegetation, overgrown railway banks, clover fields, the flowery borders of corn fields, plantations in parks, heaths and moors, sheltered and overgrown hollows such as chalk pits and old disused quarries, reed and marsh land, all these are good localities, each one inhabited by its own peculiar species, and if your route runs through a fair variety of such places you may, other things being equally favourable, depend on a good catch.

See that your time also is well chosen. Of course you cannot say exactly what the night will be till it actually comes, and, as you have to start off before it is dark, you must consider the probabilities of the future from the present condition of the air. Let it be a night when a bright moon is not due, and if it follow a warm and moist day with a south or south-west wind, or if drizzly, so much the better; but let your feet be shod with boots that will permit you to wade through moist herbage without danger, and take a waterproof if necessary.

It is always advisable to be on your hunting ground before twilight sets in, as a number of moths venture out before the sun has disappeared; and then you can work on till midnight if you feel inclined, or even extend your labours till the early hours of the morning.

Before dusk you will meet with many of the little Tortrices ([page 298]) in sheltered spots, and a little later the Geometræ and Hawks will be on the wing. Thus, before dark, you may make good use of your net, dealing with your captures just in the same way as recommended in the case of butterflies.

After a time, however, the lantern will have to be brought to your assistance in making known the whereabouts of the later species, consisting chiefly of the Noctuæ, many of which do not make their appearance till it is quite dark. If now you carry your lantern in your left hand, your work will be rendered somewhat difficult and tedious, for, although one hand is sufficient to manage the net properly, you are compelled to rest your light on the ground every time you make a capture, as it is impossible to box your specimens unless both hands are quite free. This difficulty is easily overcome by suspending the lantern by means of a string or strap placed round your neck, allowing it to hang on your chest; and a further advantage is gained by having a second strap round your chest to prevent it from swaying about with every movement of your body. This arrangement gives you both hands perfectly free during the whole time, and also prevents the necessity of continually bringing yourself into a stooping or kneeling posture while you are examining or boxing the specimens you have netted.

There are now two courses open to you. Either you can kill and pin the moths as you catch them, fixing each one securely in the collecting box, or you may simply shut each one in a separate pill box and leave the remainder of the work to be done at home. If the ordinary collecting box only is used, a little of your time is necessarily occupied in pinning and transferring, and if many insects are about such an occupation may appear to you to be a waste of valuable time. But this is not all. Often and often will you find that while thus engaged a splendid moth will come and flutter round your light; and, before you have time to drop your collecting box and pick up the net, the fine creature you would have prized has darted off again. This certainly seems to speak in favour of the pill-boxing method, but it must be remembered that a few of the moths will continue to flutter after they have been boxed, so that when you arrive home they are more or less damaged, a large number of the scales that once adorned the wings now lying on the sides and bottom of the boxes. Perhaps the best plan is to take both the collecting box and also a quantity of pill boxes, and a little experience will soon show you which is the better accommodation for certain kinds.