Home / Albums / Natural History / Insects 102
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The Simuliidæ, or black flies, are small, dark, or black flies, with a stout body and a hump-back appearance. The antennæ are short but eleven-segmented, the wings broad, without scales or hairs, and with the anterior veins stout but the others very weak. The mouth-parts are fitted for biting.
45 visits
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Sepsis violacea; puparium and adult
37 visits
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Image 4715
36 visits
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Image 4714
37 visits
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Image 4713
28 visits
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Image 4712
30 visits
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Image 4711
35 visits
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Image 4710
31 visits
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Image 4709
37 visits
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Image 4708
34 visits
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Image 4707
38 visits
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Image 4706
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Image 4704
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Image 4703
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Image 4702
42 visits
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Image 4701
38 visits
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Image 4700
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Image 4699
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Image 4698
34 visits
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Image 4697
31 visits
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Image 4696
32 visits
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Image 4695
33 visits
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Image 4694
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Image 4693
38 visits
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Image 4692
36 visits
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Image 4691
40 visits
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Image 4690
38 visits
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Image 4689
31 visits
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Image 4688
31 visits
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Image 4687
41 visits
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Image 4686
34 visits
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Image 4685
31 visits
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Image 4684
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Image 4683
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Image 4682
23 visits
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Image 4681
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Image 4680
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Image 4679
28 visits
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Image 4678
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Image 4676
30 visits
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Image 4675
31 visits
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Image 4674
29 visits
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Image 4673
27 visits
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Image 4672
29 visits
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Image 4671
23 visits
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Image 4670
23 visits
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Image 4669
19 visits
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Image 4668
19 visits
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Image 4667
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Image 4666
21 visits
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Image 4664
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Image 4663
23 visits
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Image 4662
22 visits
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Image 4661
28 visits
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Several families of the true bugs include forms which, while normally inoffensive, are capable of inflicting painful wounds on man. In these, as in all of the Hemiptera, the mouth-parts are modified to form an organ for piercing and sucking.
The upper lip, or labrum, is much reduced and immovable, the lower lip, or labium, is elongated to form a jointed sheath, within which the lance-like mandibles and maxillæ are enclosed. The mandibles are more or less deeply serrated, depending on the species concerned.
40 visits
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Auchmeromyia luteola, the Congo floor maggot. This is a muscid of grewsome habits, which has a wide distribution throughout Africa. The fly deposits its eggs on the ground of the huts of the natives.
62 visits
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Until recently, the ticks attracted comparatively little attention from entomologists. Since their importance as carriers of disease has been established, interest in the group has been enormously stimulated and now they `rank` second only to the mosquitoes in the amount of detailed study that has been devoted to them.
The ticks are the largest of the Acarina. They are characterized by the fact that the hypostome, or "tongue" is large and file-like, roughened by sharp teeth.
46 visits
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Anopheles quadrimaculatus mosquito, male and female
42 visits
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Anopheles punctipennis. Female
42 visits
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Anopheles crucians. Female
48 visits
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n popular usage, the term "tarantula" is loosely applied to any one of a number of large spiders. The famous tarantulas of southern Europe, whose bites were supposed to cause the dancing mania, were Lycosidæ, or wolf-spiders. Though various species of this group were doubtless so designated, the one which seems to have been most implicated was Lycosa tarantula (L.). On the other hand, in this country, though there are many Lycosidæ, the term "tarantula" has been applied to members of the superfamily Avicularoidea, including the bird-spiders.
49 visits
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The yellow fever mosquito breeds in cisterns, water barrels, pitchers and in the various water receptacles about the house. In our own Southern States it very commonly breeds in the above-ground cisterns which are in general use. Often the larvæ are found in flower vases, or even in the little cups of water which are placed under the legs of tables to prevent their being overrun by ants. They have been repeatedly found breeding in the holy water font in churches. In short, they breed in any collection of water in close proximity to the dwellings or gathering places of man.
45 visits
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The tailed whip-scorpions, belonging to the family Thelyphonidæ, are represented in the United States by the giant whip-scorpion Mastigoproctus giganteus, which is common in Florida, Texas and some other parts of the South. In Florida, it is locally known as the "grampus" or "mule-killer" and is very greatly feared. There is no evidence that these fears have any foundation, and Dr. Marx states that there is neither a poison gland nor a pore in the claw of the chelicera.
41 visits
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The true scorpions are widely distributed throughout warm countries and everywhere bear an evil reputation. According to Comstock (1912), about a score of species occur in the Southern United States. These are comparatively small forms but in the tropics members of this group may reach a length of seven or eight inches. They are pre-eminently predaceous forms, which lie hidden during the day and seek their prey by night.
The scorpions possess large pedipalpi, terminated by strongly developed claws, or chelæ. They may be distinguished from all other Arachnids by the fact that the distinctly segmented abdomen is divided into a broad basal region of seven segments and a terminal, slender, tail-like division of five distinct segments
36 visits
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The Solpugida have long borne a bad reputation and, regarding virulence, have been classed with the scorpions. Among the effects of their bites have been described painful swelling, gangrene, loss of speech, cramps, delirium, unconsciousness and even death. Opposed to the numerous loose accounts of poisoning, there are a number of careful records by physicians and zoölogists which indicate clearly that the effects are local and though they may be severe, they show not the slightest symptom of direct poisoning.
25 visits
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he Diplopoda, or millipedes, are characterized by the presence of two pairs of legs to a segment. The largest of our local myriapods belong to this group. They live in moist places, feeding primarily on decaying vegetable matter, though a few species occasionally attack growing plants.
The millipedes are inoffensive and harmless. Julus terrestris, and related species, when irritated pour out over the entire body a yellowish secretion which escapes from cutaneous glands. It is volatile, with a pungent odor, and Phisalix (1900) has shown that it is an active poison when injected into the blood of experimental animals. This, however, does not entitle them to be considered as poisonous arthropods, in the sense of this chapter, any more than the toad can be considered poisonous to man because it secretes a venom from its cutaneous glands.
41 visits
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In Milan the visitation of 1630 was credited to the so-called anointers,—men who were supposed to spread the plague by anointing the walls with magic ointment—and the most horrible tortures that human ingenuity could devise were imposed on scores of victims, regardless of `rank` or of public service. Manzoni's great historical novel, "The Betrothed" has well pictured conditions in Italy during this period.
54 visits
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A flesh fly
43 visits
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(a) Normal position of the larvæ of Culex and Anopheles in the water. Culex, left; Anopheles, middle; Culex pupa, right hand figure
43 visits
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It is well known that mosquitoes, when they bite, inject into the wound a minute quantity of poison. The effect of this varies according to the species of mosquito and also depends very much on the susceptibility of the individual. Soon after the bite a sensation of itching is noticed and often a wheal, or eminence, is produced on the skin, which may increase to a considerable swelling. The scratching which is induced may cause a secondary infection and thus lead to serious results. Some people seem to acquire an immunity against the poison.
The purpose of this irritating fluid may be, as Reaumur suggested, to prevent the coagulation of the blood and thus not only to cause it to flow freely when the insect bites but to prevent its rapid coagulation in the stomach. Obviously, it is not developed as a protective fluid, and its presence subjects the group to the additional handicap of the vengeance of man.
As to the origin of the poison, there has been little question, until recent years, that it was a secretion from the salivary glands. Macloskie (1888) showed that each gland is subdivided into three lobes, the middle of which differs from the others in having evenly granulated contents and staining more deeply than the others.
46 visits
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There has already been talk of the plague of the intestinal worms and their expulsion by Kusso; the higher standing insects occur in the highlands in large quantities only in the warmer season, but are driven back into the lower lying areas by the cold rains. The locusts , Amharic Anbasa, often cause great damage, as in the other Nile countries.
61 visits
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Sometimes millions of locusts come upon the wind, and devour every green thing, so that nothing is left for man or beast.
74 visits
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DYSDERIDÆ.
A small family of spiders with only six eyes. They have also four breathing-holes in the front of the abdomen; but one pair leads to branched tubes instead of sacs. They are usually found under stones, with their legs drawn up close to their bodies, but can move very quickly when so inclined. Very few species are known, and none are common, in North America. At bottom of figure are the eyes as seen from in front.
118 visits
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MYGALIDÆ
This family includes the largest known spiders. The body is usually very hairy and dark-colored. Most species have only four spinnerets; and one pair of these are long, and are turned up behind the abdomen. They have four air-sacs under the front of the abdomen, instead of two, as other spiders. Their mandibles are very large, and work up and down, instead of sidewise. The eyes are collected together on the front of the head. They live only in warm countries. Specimens from South America are exhibited in every natural history museum. The figure represents Mygale Hentzii, a species living in Arizona and Texas.
115 visits
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Section of a spider to show the arrangement of the internal organs:
a, b, upper and under lips of the mouth; c, c, the œsophagus;
d, f, upper and under muscles of the sucking-stomach;
e, stomach; g, g, ligaments attached to diaphragm under the stomach;
J, lower nervous ganglion; k, upper ganglion;
l, l, nerves to the legs and palpi; m, branches of the stomach;
n, poison-gland; o, intestine; p, heart; R, air-sac;
S, ovary; t, air-tube; u, spinning-glands.
The intestine, o, continues backward through the abdomen to the anus, in the little knob behind the spinnerete. The brown mass which surrounds the intestine, and fills the abdomen above it, is supposed to be a secreting-organ discharging into the intestine at several points.
115 visits
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The head is not separated from the rest of the body, as in insects, but forms, with the thorax, one piece. On the front of the head are eight eyes, Q, which are differently arranged in different spiders. On the abdomen are several pairs of dark smooth spots, which mark the ends of muscles extending downward through the abdomen. The markings of this spider are very complicated. The spot on the middle of the front of the abdomen is a very common one, and, in some spiders, extends the whole length of the body. The waved lines on each side are also common, and, in long-bodied spiders, often form two bright-colored stripes, or rows of spots, running nearly straight the whole length of the abdomen.
121 visits
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In many spiders a brush of hairs takes the place of the middle claw, as in the jumping spiders. Spiders with these brushes on their feet can walk up a steep surface, or under a horizontal one, better than those who have three claws.
116 visits
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The legs are used chiefly for running, jumping, and climbing; but the front pair serve often as feelers, being held up before the body while the spider walks steadily enough on the other six. One or both of the hinder legs are used to guide the thread in spinning; the spider at the same time walking or climbing about with the other six or seven. The legs are seven-jointed; and on the terminal joint are three claws ( A, B, C) and various hair and spines.
118 visits
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The body is seen to be divided into two parts, connected only by the narrow joint, A, just behind the last pair of legs. The front half of the body, called the thorax, contains the stomach, the central part of the nervous system, and the large muscles which work the legs and jaws. The hinder half, the abdomen, contains the intestine, the breathing-organs, the principal circulating-vessels, the organs of reproduction, and the spinning-organs. Connected with the thorax are six pairs of limbs, four pairs of legs, B B B B, a pair of palpi, C, and a pair of mandibles, D.
122 visits
