THE METHOD OF COLLECTING INSECTS CALLED DIPTERA.
This order contains various kinds of flies and gnats; the former abound in almost every place, but they are found more particularly on all kinds of plants and flowers, especially on the umbelliferous ones, about the tops of trees, little hills, &c. Some of them fly about cattle of various kind, in the skins of which they deposit their eggs, as the oestrus bovis, &c. These insects are easily killed by a few drops of spirit of turpentine: their wings are to be expanded so that their bodies may become apparent; a little brace should be placed underneath them, to prevent their bodies being too much incurvated in drying, which they are very apt to be. Many of these are most easily taken when they begin to feed; for, in the middle of the day they are so quick and active, that it is almost impossible to catch them.
With regard to the last order of insects, distinguished by the term APTERA, they are so common, and the places they inhabit so generally known, that any information on the means of collecting them must be superfluous. Under this class are included spiders, scorpions, centipes, crabs, lobsters, &c. &c. Most of these require to be preserved in some kind of spirit; spirit of wine, proof spirit, or geneva, are to be preferred, on account of their pellucidness; though rum or brandy may, if no other spirit be at hand, answer the purpose of preserving, though not that of exhibiting them with equal advantage.
Those of the genus cancer, after being well dried or carefully baked, may be conveniently preserved in store boxes, or properly arranged in a cabinet collection. The smaller kinds of insects in general, as well as those of the order aptera, are best disposed of between talcs in sliders; such, for instance, as the termes pulsatorium,[167] the several poduræ, pediculi, pulices, acari, &c.
[167] According to Linnæus, this is the minute insect which has been long known by the English name of the death-watch, and described by a number of authors: Linnæus thus notices it; “frequens in domibus, invisum vestibus, herbariis, insectorum museis. Fœmina horologii instar pulsatoria in ligneis festucis.” Syst. Nat. p. 1015. No. 2. Geoffroy, however, says he is confident that it is not from this insect, but from the dermestes domesticus, (Syst. Nat. p. 563, No. 12,) which makes the circular holes in furniture, that the ticking noise proceeds. Hist. des Insectes, Tom. I. p. 111. & Tom. II. p. 602. Neither of these are larger than the pediculus humanus. Again, on the respectable authority of Dr. Shaw, we are assured, that the insect properly called the death-watch is a coleopterous insect of the genus ptinus, Syst. Nat. p. 565. The Doctor says, “it is chiefly in the advanced state of the spring that this alarming little insect commences its sound—the prevailing number of distinct strokes is from seven to nine or eleven—these are given in pretty quick succession, and are repeated at uncertain intervals; and in old houses, where the insects are numerous, may be heard almost every hour of the day, especially if the weather be warm. The sound exactly resembles that which may be made by beating moderately hard with the nail on a table—It is about a quarter of an inch in length.” This very able naturalist has distinguished the insect by the name of ptinus fatidicus, the beating ptinus, and supposes it to be the same with the dermestes tesselatus of Fabricius, and the ptinus pulsator of Gmelin. He also cautions us “not to confound this insect, which is the real death-watch of the vulgar, emphatically so called, with another insect, which makes a sound like the ticking of a watch, and which continues its sound for a long time without intermission: it belongs to a totally different tribe from the death-watch, and is the termes pulsatorium of Linnaeus.” Every one will agree with the Doctor in his remark, that, “it is a very singular circumstance that an animal so common should not be more universally known.” Nat. Misc. vol. iii.
Whichsoever of the three above described is the real insect, it is well known, that for a series of years the dread of it has excited the most uneasy sensations in the minds of the weak and superstitious; an unhappy prejudice which exists even to the present hour, and cannot be totally eradicated by all the powers of reason and argument. Sir Thomas Brown long since observed, “He that could extinguish the terrifying apprehensions hereof, might prevent the passions of the heart, and many cold sweats in grandmothers and nurses.” Pseudodoxia Epidemica, Book ii. Chap. 7. With the feelings of these persons a well-known satirist sports in the following lines:
———— “a wood worm
That lies in old wood, like a hare in her form:
With teeth or with claws it will bite or will scratch,
And chambermaids christen this worm a DEATH-WATCH:
Because like a watch, it always cries click,
Then woe be to those in the house who are sick;
For sure as a gun, they will give up the ghost,
If the maggot cries click, when it scratches the post.”
Swift’s Invective against Wood.
Another poet has also diverted himself with the same subject:
———— “The weather’s bell
Before the drooping flock told forth her knell.
The solemn DEATH-WATCH click’d the hour she died.”