The sawyer fly, so called from its faculty of sawing asunder the branches of trees, whose substance is its food, is about three inches in length when full grown, and is a very singular insect. Its head has somewhat the appearance of that of an elephant, it having a horny bill, like the proboscis of that animal, bending upwards from the under part, with another, pointing downwards from the upper part of its head, both of a jet black, and of a fine polish. On the inner surface of the upper bill are raised points, like the teeth of a saw, which are used by the insect in the same manner. Its body is like that of a beetle, but considerably larger, with double wings, the inner of which is like coarse gauze; and its legs are armed at each joint with crooked, sharp nails, with the same on each toe, like a bird.
The process of this insect in sawing down branches of trees is really admirable, but it is hardly possible to form an idea of the manner of doing it without a description. This work it performs by encircling the branch with its bills, the points of which it fastens well into the wood, and turning round it briskly by the strength of its wings, which make a loud buzzing noise, it in a short time saws the branch asunder. They are by many called elephant flies, from the great resemblance of their heads to that animal; they are perfectly harmless, and are caught only to be kept as curiosities.
The blacksmith fly, is so called from its making a noise resembling in sound the striking on iron. In the centre of its back is a projecting horny point, and a crevice of the same nature on the hind part of the head, near the shoulders, which being struck together by a jerk of the head and body, make a tinkling noise, that may be heard at a considerable distance; and so elastic is the membrane which joins the head and body together, that, if the insect is laid on its back, it will spring to a tolerable height upwards, and fall directly on its legs. It differs very little from the beetle in shape or size, excepting in its elastic powers, and making so singular a noise.
The fire fly is a wonderful insect, for it has a luminous quality in its head (above the eyes) under each wing, and in its tail; which, when the insect is flying, has the appearance of so many lights of candles moving in the air: or, the lights of a coach or post-chaise in a dark night, travelling towards you at a brisk rate.
Some of these flies are as big as the top-joint of a man’s thumb, others are much smaller; and the latter have that luminous quality only in their tails. They have a charming effect on the eye at night in the groves of the woods, where they are seen flying in all directions, like so many thousand sparkles of fire; forming one of the grandest spectacles of the kind that can be conceived, in Dominica’s woods “that nightly shine with insect lamps.”
The larger sort are often caught for the novelty of the light they give; if two or three of them are put into a glass, placed in a dark room, you may see distinctly any object there; or by holding a book close to the glass in which they are, you may see plainly to read the smallest print.
There is another quality remarkable in the fire flies, which is, that several of them being killed and mashed together will produce the same effect, and be as visible in letters marked out on the walls of a dark room, as if done with artificial phosphorus; and this for a considerable time after the flies are dead.
The loggerhead fly is a species of the moth, from which it differs only in the uncommon largeness of its head, and a singular quality of transparency in its body; which latter is very remarkable, for placing this fly near to the light of a candle, you may plainly distinguish every part of its vitals, and distinctly count every movement of them.