How to Collect and Preserve Insects

by Herbert H. Ross

Nets

Nets are the most important items in the collecting kit of the entomologist. For this reason nets should be rigidly constructed and handled with care.

Construction.—Nets may easily be made at home. The necessary parts are a handle, a loop or ring to be attached to it, and a cloth bag to be hung from the loop, figs. [1] and [2]. The handle should be strong and fairly light. At the net end, [fig. 1]a, a groove is cut down each side to receive the arms of the loop. The grooves are as deep as the thickness of the wire used in the loop; one groove is 3 inches long and the other 2½ inches; and each ends in a hole through the handle at right angles to the length.

The loop, [fig. 1]b, is made of steel wire, preferably three-eighths-inch piano wire, which if bent by rough usage springs back into shape and will stand a great deal of hard wear. The wire is shaped, as the figure shows, to form a loop with two straight arms, the tips of which are bent at right angles toward each other. The arms and hooks thus formed must be exactly long enough to fit along the grooves and into the holes in the handle. After the bag or net has been attached to the loop, and the wire has been fitted to the handle, the joint may either be wrapped tightly with wire, [fig. 1]c, or bound by a metal cylinder or ferrule slipped over the arms of the loop, [fig. 1]d.

The bag, about twice as long as the diameter of the loop, should be tapered at the bottom. It is made from four pieces of cloth, each cut in the shape of [fig. 2]a, and a narrow strip or band of stout muslin or light canvas, [2]b, which is to bind the bag to the wire loop. The four pieces are sewed together to form a cone-shaped bag, and one edge of the band is sewed to the top edge of the bag.

The bag may be attached to the wire loop in either of two ways. The band may be folded over the loop and sewed so that the attachment is permanent; or it may be folded over, sewed, and then slipped on the loop before the latter is fastened to the handle. In the latter case the bag must be open along one seam just below the handle a sufficient distance to allow the band to slip on and around the loop; this vent may be closed with a string lacing after the net is on the loop, and the whole fastened to the handle. A combination of this arrangement with a ferrule binding the loop to the handle is most convenient, for it allows the bag to be removed at will and a lighter or heavier one substituted according to the needs of the collector.

Fig. 1.—Net loop and handle. The short grooves cut opposite each other at the small end of the handle, a, end in holes through the handle that receive the hooks of the loop arms, b. The loop may be permanently bound to the handle with wire, c, or a removable joint may be effected with a metal ferrule that can be slipped up and down, d.

Fig. 2.—Bag and completed net. The bag is cut from four pieces shaped as in a, and the top edge of the bag is bound with a narrow strip of stout muslin or light canvas, b, by means of which the bag is attached to the loop. After the bag is on the loop, the back vent may be closed with a string lacing, as shown in the figure. This closing, which keeps the back of the net from gaping, prevents the escape of the most active insects through the back opening. The handle pictured here is a removable type, [fig. 1]d.

General Purpose Net.—Loop, heavy wire, 12 inches in diameter; bag, strong unbleached muslin or light duck, 20 to 24 inches long; handle, hardwood stick, 24 to 30 inches long.

Butterfly Net.—As above but with a longer handle and a bag of good quality marquisette or fine nylon netting.

Combination Net.—A net that includes the features and uses of the two nets described above and is a better collecting instrument may be conveniently made instead, although at slightly higher cost because of the better materials. Its loop, of 7½ gauge (three-eighths inch) piano wire, is 15 inches in diameter and allows a greater area to be covered with each sweep. The bag, of finest bolter’s silk or best quality marquisette, is 24 inches long and serves equally well for the capture of delicate insects and for beating. The handle, of straight-grained hickory or ash, is 40 inches long and permits the collector to cover greater areas in sweeping. If a cheaper net is desired, one of unbleached muslin will be satisfactory for general use.

Care and Use.—All nets are easily ripped and for this reason should be kept away from barbed wire and from thorny trees, such as locust and red haw. Also, they should be kept dry. Moisture rots the fabric, making it more easily torn. Most insects caught in a net while it is wet are unfit for a collection.

Flowers, herbs, and boughs should be swept with a sidewise motion. A sidewise sweep will collect more insects than an upward or downward sweep and at the same time mutilate less. If care is taken not to damage flowers or foliage, the same patch of plants may be visited several times with profit. The contents of the bag should be removed after every few sweeps or strokes. This practice will prevent damage to the insects caused by being jostled about in the net with a large amount of debris.