Widow's mite

“ We have seen a mite (Nothrus ovivorus, Fig. 143) busily engaged in destroying the eggs of a moth like that of the Canker worm, and Dr. Shimer has observed the Acarus? malus sucking the eggs of the Chinch bug. I have also observed another mite devouring the Aphides on the rose leaves in my garden, so that a few mites may be set down as beneficial to vegetation. While a few species are injurious to man, the larger part are beneficial, being either parasitic and baneful to other noxious animals, or more directly useful as scavengers, removing decaying animal and vegetable substances. ”

“ The legs are short and stout, and composed of five segments. The tarsi may or may not possess a claw and may terminate in a pedunculated sucker, or simple long bristle, or both. The presence or absence of these structures [Pg 73] and their distribution are much used in classification. The mites live on or under the skin of mammals and birds, where they produce the disease known as scabies, mange, or itch. Several species of the Sarcoptidæ attack man but the most important of these, and the one pre-eminent as the "itch mite" is Sarcoptes scabiei. ”

“ And the parasites themselves, do they lead unmolested lives? Are they the final arbiters of lire and death in the insect world? if you are fortunate sometime while study- ing aphids out-of'-doors, you may see a tiny black mite, no bigger than the small;est gnat, hovering about an in- fested plant or darting uncertainly from one leaf to another, with the air of searching for something but not knowing just where to look. You would probably suspect the intruder of being a parasite seeking a chance to place an egg in the body of an aphid ”

“ The body is oblong, square behind; the head is long and pointed, while the maxillæ end in a long, curved, toothed, sickle-like blade. That this creature has the habits of the itch mite is suggested by the [Pg 120] curious, large, hair-like spines with which the body and legs are sparsely armed, some being nearly half as long as the body. These hairs are covered with very fine spinules. Those on the end of the body are regularly spoon-shaped. These strange hairs, which are thickest on the legs, probably assisted the mite in anchoring itself in the skin of its host. ”

“ This parasite is equipped with stylets which pierce the [56] skin at the seat where the mange mite penetrates the skin, and produces small red spots followed by a blister filled with serum, which ruptures, the serum drying and forming a small scab. It is in this way that innumerable mange mites cause the piling up of scabs thus producing a very scaly condition. As Mange advances, the scaly patches eventually pile up until they attain the thickness of one-half inch, unless these scabs have been severely rubbed. ”

“ The presence of their hypo-pharynx in the skin causes the surrounding tissues to harden and form a cylindrical tube—the so-called proboscis.
The amount of trouble they cause varies very greatly in different people. Children and women with soft skins suffer, as a rule, most; but, as happens in the case of other biting insects, certain individuals seem to be almost immune, whilst others suffer very considerably. [94] The trouble is caused by the mite implanting its mouth-parts in the skin—preferably in the hair-follicles or the sweat-glands. When it is once fixed it rarely moves. ”

“ Bourguignon found that under the most favorable conditions the mites of Sarcoptes scabiei equi would live for sixteen days.
The disease designated the "itch" or "scabies," in man has been known from time immemorial, but until within less than a hundred years it was almost universally attributed to malnutrition, errors of [Pg 75] diet, or "bad blood." This was in spite of the fact that the mite was known to Mouffet and that Bonomo had figured both the adult and the egg and had declared the mite the sole cause of the disease. ”

“ For severe itching he advises smearing the bites with vaseline, which is slightly impregnated with camphor or menthol. Medical aid should be sought when complications arise.
The Dermanyssidæ are Gamasid mites which differ from others of the group in that they are parasitic on vertebrates. None of the species normally attack man, but certain of them, especially the poultry mite, may be accidental annoyances. ”

“ The affected animals will even make attempts to bite themselves, due to the agony produced by the mange mite. If the skin is examined by the aid of a magnifying glass, the mange mite can be easily noticed, or by scraping the skin with a knife and placing the scabs on a dark paper and exposed to the warmth of the sun, the mange mite moving about can readily be seen with the naked eye. Mangy sheep become very poor and eventually die. ”

“ Another disagreeable arachnid is the little harvest bug (Leptus autumnalis) , which not only excites irritation during its crawling motion on the human skin, but even succeeds in burying itself near the hairs. The irritation thus produced is almost unbearable. This mite attacks various animals, especially dogs and cats. I myself once suffered severely from this species in consequence of fondling a young wild rabbit which, as I afterwards discovered, was much infested. When the parasites had reached my left arm-pit they occasioned extreme torture. ”

“ These parts form a beak which the mite or tick insinuates into the flesh of its host, upon the blood of which it subsists. While many of the mites are parasitic on animals, some are known to devour the eggs of insects and other mites, thrusting their beaks into the egg, and sucking the contents. ”

“ The minute whitish mites (Fig. 20) that cause this disgusting disease are barely visible to the naked eye. They are usually very sluggish but become more active when warmed. They live in burrows just beneath the outer layer of skin, sometimes extending deeper and causing most intense itching. As the female burrows, she lays her eggs from which come the young mites that are to spread the infection. Various sulphur ointments and washes are used as remedies. Cleanliness will prevent infection. ”

“ One never knows where or at what hour a stray shot or splinter will fall, and it is pitiful sometimes to hear cries for dolly from a prattling mite who may herself be fatherless or motherless to-morrow. ”

“ SYMPTOMS: The mange mite attacks the skin and produces a thickness of
its outer surface, covering it with crusts and scabs, with a consequent
loss of hair. Intense itching accompanies the disease, and affected
horses continually bite and rub themselves.
Psoroptic Mange commences at the root of the tail, or at the roots of
the mane on the neck or withers, and gradually spreads over the back, up
to the head, over the sides, and finally affects the entire body. In
cases of long standing the skin becomes ulcerated, the animal becomes
greatly weakened, emaciated and finally dies. ”

“ If the part where a little black spot or a pustule is seen be squeezed rather hard, the oily matter there accumulated will be forced out in a 628 globular form. This minute mite is less than one-fiftieth of an inch in length; if it be laid on a glass slide, and a small quantity of glycerine added to cause the separation of the harder portions, the parasite in all probability will float out, and, by means of a fine-pointed pencil or brush, can be transferred to a clean slide and mounted in Canada balsam. An allied species is found in the skin of dogs suffering from mange. ”

“ The eggs, in warm weather, hatch in about a week, and the young animal may be seen sometimes for a day together struggling to get rid of its egg-shell. The mite is a very voracious animal, feasting equally upon animal and vegetable substances. It is also extremely tenacious of life: for, upon the authority of Leuwenhoek, though highly discreditable to his sense of humanity, we are assured that a mite lived eleven weeks after he had glued it to a pin, in order to make his observations. ”

“ According to Keïsuke Tanaka, however, a connection certainly does exist, inasmuch as the akamushi, like Leptus, attacks persons to suck blood. If the mite is not removed, or if the spot attacked is injured by scratching, etc., a papule surrounded by a red area forms, and a pustule ensues; and finally a black scab covers the seat of injury. The lesion becomes the point of entrance of bacteria, especially a species of proteus which produces river fever. If the mites are carefully removed no general illness takes place. ”

“ Fowls, when allowed to roost in stables, sometimes convey these mites to horses, torturing the poor brutes nearly to death, the owner being unable to decide what malady afflicts them. The mite is easiest served in the cages of singing birds. That they feed upon the bird is shown by their digestive organs being full of blood. ”

“ There are eight legs, four situated close to the head and four posteriorly. The entire parasite scarcely exceeds a fifth of a line in length. The female mite is to be looked for at the blind end of a burrow or at the roof of a vesicle. ”

“ A most singular mite was discovered by Newport on the body of a larva of a wild bee, and described by him under the name of Heteropus ventricosus. The body of the fully formed female is long and slender. After attaining this form, its small abdomen begins to enlarge until it assumes a globular form, and the mass of mites look like little beads. Mr. Newport was unable to discover the male, and thought that this mite was parthenogenous. It will be seen that the adult Demodex retains the elongated, worm-like appearance of the larva of the higher mites, such as Typhlodromus. ”

“ The colour is bright red, changing to a deep orange. The red mite lives freely upon the foliage, and does not produce a web, as do related species; the adult female is bright red to dark brownish-red, rather globular in shape, with comparatively stout legs and numerous spine-like hairs on the back. Although the eggs of the European red mite are exposed on bark and readily accessible to sprays during the winter, no effective winter wash for their control is yet known; the most satisfactory method for checking the pest is to spray the active stages of the mite with summer oil. ”

“ Scrupulous cleanliness should be exercised to prevent and remove them. Several members of this family are parasitic on cats. One species is found on dead bodies. A case has been cited where one was observed on the brain of a dead soldier, which had just been opened. Although the observer thought that the mite had been domiciled there, and upon the strength of this case the statement is often made that they are sometimes found in the brain, it is probable that the mite was in some way conveyed to the brain after it had been opened. ”

“ The mites are closely related to the ticks, and although none of them has yet been shown to be responsible for the spread of any disease their habits are such that it would be entirely possible for some to transmit certain diseases from one host to another, from animal to animal, from animal to man, or from man to man. A number of these mites produce certain serious diseases among various domestic animals and a few are responsible for certain diseases of men. ”

“ It is a web-spinning species, and the minute yellowish-red eggs are to be found scattered among a fine web attached to the lower surface of leaves as a rule. The adult mite (Fig. 13, 9) is very active; it is somewhat larger than the two foregoing species, and of a yellowish-green colour, with a pair of conspicuous dark spots on the back. Though this mite can be held in check by the application of lime-sulphur sprays, advantage should be taken of thorough cultivation during the dormant season, since the mite hibernates on weeds and among dead leaves and in the soil. ”

“ Mites are not true insects, but are the most degraded of spiders. The sub-class Arachnida are at once recognized by their eight legs. The order of mites (Accorina) , which includes the wood-tick, cattle-tick, etc., and mites, are quickly told from the higher orders--true spiders and scorpions--by their rounded bodies, which appear like mere sacks, with little appearance of segmentation, and their small, obscure heads. The mites alone, of all the Arachinida, pass through a marked metamorphosis. Thus the young mite has only six legs, while the mature form has eight. ”

“ They are not permanently parasitic, and if left alone will leave their temporary host to resume the active life characteristic of the adult mite, which is predatory in habits, preying upon minute living animal organisms. ”

“ CAUSE: Produced by a parasite called Cylodites Nudus, which bears a
close resemblance to the parasite causing mange or scabies in the
domesticated animal. Owing to the peculiar construction of their
breathing organs fowls are more susceptible to parasites than animals.
In addition to affecting the lungs, the Air Sac Mite may extend its
operations to the intestines, kidneys, liver and bones.
SYMPTOMS: Unthriftiness is first noticed, but after the parasites become
numerous, the fowl shows signs of difficult breathing, perhaps
terminating in bronchial pneumonia. ”

“ It is seldom noticed, being so small, and the uninitiated are often alarmed at the symptoms. Saleratus water or salt water will allay the irritation, but sulphur ointment effects a speedy cure.
Another red mite, belonging to a different genus, makes itself useful by preying on insects. One species, Trombidium parasiticum (Fig. 2) , is found on the house-fly, which in some seasons is so infested that hardly one can be caught that is not loaded with mites clinging to the base of its wings. This or closely related species are found on spiders and mosquitoes, which they help to kill off. ”