6. Over the other end of the 5-inch piece, slip one end of the rubber tubing, [fig. 4]f.
7. Into the other end of the rubber tubing slip the 3-inch piece of glass tubing, [fig. 4]g, so that the rounded end of glass is exposed.
8. Complete the assembly of the aspirator by placing the rubber stopper snugly into the vial. The vial aspirator is now ready for use.
If a piece of glass tubing 1¼ inches in diameter and 8 inches long is available, then a tube aspirator can be made, [fig. 5]. In making a tube aspirator, use two one-hole rubber stoppers, [5]b. Cut the pieces of glass tubing as shown in [fig. 5]c, [5]e, and [5]g. Using a piece of rubber tubing, [5]f, complete the minor details as described for the vial aspirator, not forgetting the cheesecloth, [5]e, and assemble the parts as shown in [fig. 5].
Use and Care.—To catch an insect with the aspirator shown in [fig. 4] or [fig. 5], put end piece, g, in your mouth, grasp the vial or tube, a, in your dexterous hand, aim the intake tube, c, at the insect and almost touching it; suck suddenly and hard. The air current pulls the insect in; the insect usually does not find its way into the intake tube to crawl out. The cheesecloth, e, prevents the insect from being sucked into your mouth.
To kill insects in the aspirator, use a small cyanide bottle, [4]i, which is inserted in a cork, [4]h, that has been partially bored through to receive it. This cork should be the exact size of the vial or tube for which it is intended.
Fig. 6.—Sifter with hand grips. Debris containing insects is sifted over a piece of white oilcloth. The sifter, not more than half full, is shaken gently at first and then violently. Finally the debris that cannot be shaken through the sifter is emptied on the oilcloth, and specimens too large to go through the mesh of the sifter are captured. Patience is required to get the best results with the sifter, which provides one of the best methods for winter collecting.
To use the cyanide cork with the vial aspirator shown in [fig. 4], simply exchange the corks. If the glass tube aspirator is used, plug the intake tube, 5c, with a tapered paper plug or a leaf, jar the insects away from the stopper at the opposite end, remove this stopper cautiously, and quickly insert in its place the cyanide cork. When the specimens are stupefied, they may be transferred to another bottle.
The cyanide corks are highly poisonous. Between times of use with an aspirator, keep each of these corks inserted tightly in a bottle or vial labeled “POISON,” as in [fig. 3].