Directions for Collecting and Preserving Insects

by Charles V. Riley

“The bag should taper to the bottom, and in any case its length should be fully twice the diameter of the hoop, so that by giving the net a twist, the mouth may be closed and the contents thus secured. The sweeping-net may be protected around the hoop with leather, and in use should be kept in a steady and continued back-and-forth motion, over and touching the plants, until the contents are to be examined; when, by placing the head at the opening and quietly surveying the restless inmates, the desiderata may be secured and the rest turned out. A sudden dash of the air-net will usually lay any flying object at the bottom. A net for aquatic insects may be made on the same principle, but should be stout, with the meshes open enough to allow free passage of water, and the bag not quite as deep as the diameter of the hoop. A forceps net, which consists of two gauze or bobbinet covered frames, having riveted handles, so as to close like a pair of scissors, is employed for small insects; but I find little use for it. A coarse sieve, together with a white towel or sheet, will be found of great service for special occasions, particularly in the spring, when the search for minute insects found under old leaves, or for pupæ around the butts of trees, is contemplated. With the sheet spread on the ground, and a few handfuls of leaves and leafy mold sifted over it, many a minute specimen will be separated from the coarser particles and drop to the sheet, where the eye may readily detect it. Conversely, the earth taken from around trees may be sifted so as to leave in the sieve such larger objects as pupæ, etc. Another favorite plan, with some collectors, of obtaining specimens, especially night-flying moths, is by ‘sugaring.’ This consists of applying to the trunks of trees or to strips of cloth attached to the trees some sweet, attractive, and stupefying preparation. Diluted molasses or dissolved brown sugar, mixed with rum or beer, is most frequently employed. I have found sugaring of little use till after the blossoming season, and it is almost impossible to so stupefy or intoxicate an insect that it will remain upon the sugared tree till the next morning. I generally sugar at eve, and visit the tree several times between sundown and midnight, armed with wide-mouthed killing-bottles and accompanied by a second person, who carries a dark-lantern. Isolated trees, on the edges of woods, give the best results. Everybody knows how some poor moths will persist in flitting around a light until they singe their wings; and, as many insects are strongly attracted to bright artificial light, it may be employed with good results, especially during warm and damp evenings. The collector should never go unprovided with a small box or tube full of different sized pins (a corked cartridge-tube makes a good box,) a pair or two of forceps, a pair of scissors, a little mucilage, and the killing apparatus to be described.”

With these general remarks, it will be well to consider some of the important paraphernalia more in detail.

[COLLECTING APPARATUS.]

[The Sweeping Net.]—A multitude of insects of all orders feed or rest on grasses and other low plants. Upon close inspection of these plants a careful observer will be able to secure, without any instruments, not only many mature insects, but also many larvæ in connection with their food-plants. This is laborious and slow work, only necessary on special occasions. The beating net, which is constructed on the same general plan as the butterfly net, is valuable here as a time saver. By holding the handle of the net firmly in one hand and quickly sweeping over the plants first from right to left, and then, after quickly turning the net again, sweeping from left to right, most insects coming within reach of the sweep will fall into the bag and may be easily taken out and put into the collecting-vials. From this mode of operation it is evident that the sweeping net must be stronger in all its parts than the butterfly net, but otherwise it may be made on the same plan.

Fig. 47.—The Deyrolle Sweeping Net. a, net entire; b, frame; c and d, attachment of frame and handle (original).

The ring should be rigid, made of brass or iron, either of one piece or of two pieces, and fastened to the handle or stick in the same way as the butterfly net. The bag need not be as long as in the butterfly net, about 18 inches being sufficient, but it should be of stout cotton or linen and the bottom should preferably be sewed in as a round piece, so as to avoid corners. Care needs to be bestowed on the fastening of the bag on the ring, for by the use of the net the part of the bag sewed around the ring is soon chafed through. To prevent this a strip of leather is sewed over the cotton along the rim, but since even this must be frequently renewed some other devices are used to give greater durability to the net. In the pattern of a beating-net originally sold by Deyrolle in Paris, the metal ring was flattened, with the narrow edge pointing upwards and the broad side pierced with holes at suitable intervals and grooved on the outer surface between the holes. The bag is sewed on to the inner side of the ring by stout twine, which passes from one hole to the next and is thus prevented from coming in contact with obstructive objects, and only the bottom of the bag wears and will need to be occasionally mended or renewed.

Fig. 48.—Beating net, opened and attached to handle,
with frame of same folded.
(After Kiesenwetter.)

Another method of preventing the tearing of the upper rim of the bag is described and illustrated in Kiesenwetter's useful volume “Der Naturaliensammler” from which I shall frequently have occasion to quote. In this net the main ring is of rounded iron wire on which a number of brass rings are slipped. These must be but little larger than the diameter of the wire. These little brass rings should not be more than 30 mm. or at most 40 mm., distant from each other, and to them the upper rim of the bag is sewed with very strong twine and is thus protected from wear and tear. The handle or stick of the net should be firmly and solidly attached to the ring and should be stout and not liable to break. I prefer a rather short stick, say not longer than two feet.