A closely allied species is known as the Harvest-bug. This almost invisible atom burrows into the human skin and there deposits its eggs, causing excessive irritation and annoyance to the workers in corn-fields.
I will now turn from the mites to another cheese-inhabitant, Piophila casei. Few people are likely to have noticed the perfect insect, a small black fly with whitish wings margined with black; it is very inconspicuous, and we should hardly suspect its object in visiting our cheese. When cheeses are made and placed in a room to dry, before the outside rind has had time to harden, the Piophila will seek out some crevice in which to deposit its eggs. The creature is furnished with an ovipositor, which it can thrust out to a great length so as to penetrate to a considerable depth into the cracks of the cheese, and there it will lay as many as two hundred and fifty eggs. These hatch into white grubs without feet, but having two horny claw-shaped mandibles which enable them to bore into the cheese upon which they feed.
The breathing apparatus of the cheese-maggot is very remarkable, consisting of two tubes at the head and two at the tail, so the grub can breathe at either end of its body. Lest any particles of cheese should obstruct the front pair of tubes the little creature has the power of drawing over them a fold of the skin, and whilst they are thus closed it breathes through the air-tubes in the tail. A cheese inhabited by these grubs soon grows moist and rotten, because they have the power of emitting a liquid which softens and corrupts the cheese and renders it suitable for the food of the maggot.
The leaping power of these larvæ is truly surprising. Swammerdam, who seems to have carefully studied this creature, says: “I have seen one whose length did not exceed a fourth of an inch leap out of a box six inches deep, that is twenty-four times the length of its own body.” The grub cannot crawl, as it has no legs; it must therefore progress by leaps; this it achieves by erecting itself on its tail, which is furnished with several knobs or warts to enable it to keep its balance; then, bending itself into a ring, it lays hold of the skin of its tail, and, suddenly letting go with a jerk, it can, by a succession of springs, cover a surprising distance on a level surface. In considering the life-history of this despised creature I cannot but endorse the devout remark of the great naturalist I have just quoted. He says: “I can take upon me to affirm that the parts of this maggot are contrived with so much art and design that is impossible not to acknowledge them to be the work of infinite power and wisdom from which nothing is hid and to which nothing is impossible. It could not be the production of chance or rottenness, but the work of the same Omnipotent Hand which created the heavens and the earth.”
LEPISMÆ.
LEPISMÆ.
LONG ago, I remember reading with enjoyment a little essay I met with somewhere, in which were described the various living creatures one would be likely to meet with in one’s garden, if one took a stroll at night with a lantern. Beetles would be seen crossing the path, worms moving stealthily in search of food, moths hovering over the flowers; if one were quiet and still for a little time even mice and shrews might be watched foraging about bent on their own special errands.
I have indulged in such a nocturnal garden ramble occasionally, but I think it needs younger eyes than mine now are, and perhaps exceptional weather to ensure a glimpse of nature on the prowl; at any rate, I have not been very fortunate in that way. My attention during the past year has been specially directed to house-dwelling creatures, and my rambles have been carried on indoors instead of in the garden. When I think of the life-histories of the Cork Moth, of the various Cloth Moths, of the Death-Watch, of the beetles I have found at work upon the specimens in my museum, of the Solitary bees and wasps in the crevices and angles of the outer brickwork of the house, and, finally, of the creature which I am now about to describe, I think it must be admitted that there is a field for entomological study inside as well as outside our dwellings.