Worst of all flies, though fortunately rare in the North (it has been known to reach Canada), is the screw-worm fly (Compsomyia macel-laria), a bright metallic-green insect with golden reflections and four black stripes on the upper part of the body. This is a blow-fly which has the sickening habit of laying its eggs in wounds, and even in the nostrils of sleeping men. Several fatalities from this cause have been reported in our country; they have been much more numerous in South America. The gusanero of tropical America is described by a traveler as " a beast of a fly that attacks you, you know not when, till after three or four months you know that he has done so by the swelling up of the bitten part into a fair-sized boil, from which issues a maggot of perhaps an inch and a half in length." Another Amazonian fly of similar habits is the birni, whose larva generates a grub in one's skin that requires careful extraction, lest it be crushed in the operation, " and then," said a native, " gentlemen often go to o outro mundo" (the other world). The motiica of Brazil has ways similar to those of our black-fly, and, like it, can easily be killed with one's fingers.
While I am on this topic, it may add a little to the contentment of those outers who are unable to seek adventure in faraway lands, but must needs camp within a hundred miles or so of home, if I transcribe from the pages of a well-known naturalist the following notes on some of the impediments to travel in the tropics:
"But the most numerous and most dreaded of all animals in the middle Amazons are the insects. Nearly all kinds of articulate life here have either sting or bite. The strong trade wind keeps the lower Amazons clear of the winged pests; but soon after leaving Manaos, and especially on the Maranon in the rainy season, the traveler becomes intimately acquainted with half a dozen insects* of torture:
(1) The sanguinary mosquito. . . . There are several species, most of them working at night; but one black fellow with white feet is diurnal. Doctor Spruce experimented upon himself, and found that he lost, by letting the blood-letters have their own way, three ounces of blood per day. . . . The ceaseless irritation of these ubiquitous creatures makes life almost intolerable. The great Cortez, afier- all his. victories, could not forget his struggles with these despicable enemies he could not conquer. Scorpion with cocked tails, spiders six inches in diameter, and centipedes running on all dozens, are not half so bad as a cloud of mosquitoes. . . .
(2) The pium, or sand-fly, a species of trombidium called mosquito in Peru. It is a minute, dark-colored dipter with two triangular, horny lancets, which leave a small, circular red spot on the skin. It works by day, re* lie zing the mosquito at sunrise. It is the great scourge of the Amazons. Many a paradisiac spot is converted into an inferno by its presence. There are several species, which follow one another in succession through the day, all of them being diurnal. Their favorite region is said to be on the Cassiquiare and upper Orinoco.
(3) The maruim, which resembles the pium. They are infinitely numerous on the Jurua. Humboldt estimated there were a million to a cubic foot of air where he was.
(4) The motuca, called tdbono on the Marafion (Hadrus lepidotus), resembling a small horse-fly, of a bronze-black color, with the tips of the wings transparent, and a formidable proboscis. . . .
(5) The moquim ... a microscopic scarlet acarus, resembling a minute crab under the glass. It swarms on weeds and bushes, and on the skin causes an intolerable itching. An hour's walk through the grassy streets of Teffe was sufficient to cover my entire body with myriads of moguims, which it took a week, and repeated bathing with rum, to exterminate.
(6) Carapdtos, or ticks (ixodes), which mount to the tips of blades of grass, attach themselves to the clothes of passersby, and bury their jaws and heads so deeply in the flesh that it is difficult to remove them without leaving the proboscis behind to fret and fester. In sucking one's blood they cause no pain; but serious sores, even ulcers, often result. . . .
These few forms of insect life must forever hinder the settlement of the valley. . . . Besides there are ants . . . innumerable in species and individuals, and of all sizes, from the little rtd ant of the houses to the mammoth to-kandera, an inch and a half long. , . . The latter . . . bites fiercely, but rarely causes death. Doctor Spruce likens the pain to a hundred thousand nettles. . . . On the Tapa-jos lives the terrible fire-ant . . . whose sting is likened to the puncture of a red-hot needle. The saiibas are not carnivorous, but they make agriculture almost impossible. . . . There are black and yellow wasps. . . . The large, hairy caterpillars should be handled with care, as the irritation caused by the nettling hairs is sometimes a serious matter. Cockroaches are great pests in the villages. Lice find a congenial home on the unwashed Indians of every tribe, but particularly the Andean. Jiggers and fleas prefer dry, sandy localities; they are accordingly most abounding on the mountains. The Pacific slope is worthy of being called flea-dom."—Orton, The Andes arid the Amazons, pp. 484-487.
The moquim mentioned above answers the description of our own chigger, jigger, red-bug, as she is variously called, which is an entirely different beast from the real chigger or chigoe of the tropics. I do not know what may be the northern limit of these diabolic creatures, but have made their acquaintance on Swatara Creek in Pennsylvania. They are quite at home on the orairies of southern Illinois, exist in myriads on the Ozarks, and throughout the lowlands of the South, and are perhaps worst of all in some parts of Texas. The chigger, as I shall call it, is invisible on one's skin, unless you know just what to look for. Get it on a piece of black cloth, and you can distinguish what looks like a fine grain of red pepper. Put it under a microscope, and it resembles, as Orton says, a minute crab. It lives in the grass, and on the under side of leaves, dropping off on the first man or beast that comes its way. Then it prospects for a good place, where the skin is thin and tender, and straightway proceeds to burrow, not contenting itself, like a tick, with merely thrusting its head in and getting a good grip, but going in body and soul, to return no more. The victim is not aware of what is in store for him until he goes to bed that night. Then begins a violent itching, which continues for a week or two. I have had two hundred of these tormenting things in my skin at one time.