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.
[Illustration: 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_.]
[Illustration: 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.