- Foot of Epeira Vulgaris
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. - Foot of Attus Mystaceus
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. - Flea
The strength and beauty of this small creature, had it no other relation at all to man, would deserve a description. For its strength, the Microscope is able to make no greater discoveries of it then the naked eye, but onely the curious contrivance of its leggs and joints, for the exerting that strength, is very plainly manifested, such as no other creature, I have yet observ'd, has any thing like it; for the joints of it are so adapted, that he can, as 'twere, fold them short one within another, and suddenly stretch, or spring them out to their whole length, that is, of the fore-leggs, the part A, of the Scheme, lies within B, and B within C, parallel to, or side by side each other; but the parts of the two next, lie quite contrary, that is, D without E, and E without F, but parallel also; but the parts of the hinder leggs, G, H and I, bend one within another, like the parts of a double jointed Ruler, or like the foot, legg and thigh of a man; these six leggs he clitches up altogether, and when he leaps, springs them all out, and thereby exerts his whole strength at once. - Flea
- Filaria in the muscles and labium of Culex
When the blood of an infested individual is sucked up and reaches the stomach of such a mosquito, the larvæ, by very active movements, escape from their sheaths and within a very few hours actively migrate to the body cavity of their new host and settle down primarily in the thoracic muscles. There in the course of sixteen to twenty days they undergo a metamorphosis of which the more conspicuous features are the formation of a mouth, an alimentary canal and a trilobed tail. At the same time there is an enormous increase in size, the larvæ which measured .3 mm. in the blood becoming 1.5 mm. in length. This developmental period may be somewhat shortened in some cases and on the other hand may be considerably extended. The controlling factor seems to be the one of temperature. The transformed larvæ then reenter the body cavity and finally the majority of them reach the interior of the labium. A few enter the legs and antennæ, and the abdomen, but these are wanderers which, it is possible, may likewise ultimately reach the labium, where they await the opportunity to enter their human host. - Fight between an Ordinary Roller Spider and a Scorpion
The Roller Spider hides during the day in crevices of the loamy soil, in reed beds or under stones; at night she goes out for robbery and catches Insects. Tests on large specimens have shown that she also attacks large animals. A 52 mm Roller Spider. body length grabbed a 105 mm. long Scorpion at the root of the tail, bit it off and then devoured the whole animal. However, this victory was only due to chance, as it turned out, when a second Scorpio was brought to her and she attacked them from the front; this animal held its enemy with the claws and wounded it with the poison spine, to which it succumbed after a few convulsions. {trasnslated by Google] - Field Scorpion
Field Scorpion ( Buthus occitanus ): - a) top viw.-b) ventral side of the abdomen prior to: the 1st section - Every good mother should be the honored queen of a happy family
The group of bees represents the attitude in which the bees surround their Queen or Mother as she rests upon the comb. - Evania appendigaster
- Epithelium underlying poison hairs of the larva of the browntail moth (larger scale)
- Epithelium underlying poison hairs of the larva of the browntail moth
- Eggs of Anopheles
- Egg-capsule of P. orientalis
A external view B opened C end view. The eggs of the Cockroach are laid sixteen together in a large horny capsule. This capsule is oval, with roundish ends, and has a longitudinal serrated ridge, which is uppermost while in position within the body of the female. The capsule is formed by the secretion of a “colleterial” gland, poured out upon the inner surface of a chamber (vulva) into which the oviducts lead. The secretion is at first fluid and white, but hardens and turns brown on exposure to the air. In this way a sort of mould of the vulva is formed, which is hollow, and opens forwards towards the outlet of the common oviduct. Eggs are now passed one by one into the capsule; and as it becomes full, its length is gradually increased by fresh additions, while the first-formed portion begins to protrude from the body of the female. When sixteen eggs have descended, the capsule is closed in front, and after an interval of seven or eight days, is dropped in a warm and sheltered crevice. In Periplaneta orientalis it measures about ·45 in. by ·25 in. - Echidnophaga gallinacea
- Dysderidæ
Dysdera Interrita 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. - Dryocora howittii - Larva
Dryocora howittii - Larva - Dryocora howittii
Dryocora howittii - Drassidæ
A large family of spiders, varying greatly in shape, color, and habits. Most of them are dull colored, and live under stones, or in silk tubes on plants, and make no webs for catching insects. Their eyes are small, and arranged in two rows on the front of the head. Their feet have two claws and a bunch of flat hairs. The spinnerets are usually long enough to extend a little behind the abdomen. The figure is a Drassus, and the eyes as seen from in front. - Dorcus punctulatus
Dorcus punctulatus - Dome-like House of Cicada
Longitudinal Section Showing Pupa in Two Positions. In localities where the soil is low and swampy, a remarkable chamber is built up by the larva, where the pupa may be found awaiting the time of its change to the winged state. These chambers were first noticed by S. S. Rathvon, at Lancaster, Pa., and are from four to six inches above the ground, and have a diameter of one inch and a quarter. When ready to emerge the insect backs down to an opening which is left in the side of the structure on a level with the surface of the ground, issues forth and undergoes its transformation in the usual manner. This peculiar habit of nest-building, which is so unlike what is customary with the Cicadidæ, or with Hemiptera in general, points to a high degree of intelligence among these insects, showing a remarkable ability to adapt themselves to environing circumstances. - Dog flea
- Dipylidium caninum. The double pored tapeworm of the dog
- Dipylidium caninum. Rostrum evaginated and invaginated
- Diagram of a longitudinal section of a mosquito
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. - Dermatophilus penetrans
The chigoes, or true chiggers, are the most completely parasitic of any of the fleas. Of the dozen or more known species, one commonly attacks man. This is Dermatophilus penetrans, more commonly known as Sarcopsylla penetrans or Pulex penetrans. This species occurs in Mexico, the West Indies, Central and South America. The males and the immature females of Dermatophilus penetrans closely resemble those of other fleas. They are very active little brown insects about 1-1.2 mm. in size, which live in the dust of native huts and stables, and in dry, sandy soil. In such places they often occur in enormous numbers and become a veritable plague. - Dermanyssus gallinæ, female
- Demodex folliculorum
- Dancing Mania
- Cærostris Mitralis, in profile
- Cærostris Mitralis
- Culicoides guttipennis - (a) adult, (×15) (b) head of same (c) larva (d) head (e) pupa
- Culicoides guttipennis - mouth parts of adult
Of the twenty or more species of this genus occurring in the United States the following are known to bite: C. cinctus, C. guttipennis, C. sanguisuga, C. stellifer, C. variipennis, C. unicolor. - Culex sollicitans. Female
- Culex larva showing details of external structure
The larvæ are elongate, with the head and thorax sharply distinct. The larval antennæ are prominent, consisting of a single cylindrical and sometimes curved segment. The outer third is often narrower and bears at its base a fan-shaped tuft of hairs, the arrangement and abundance of which is of systematic importance. About the mouth are the so-called rotary mouth brushes, dense masses of long hairs borne by the labrum and having the function of sweeping food into the mouth. The form and arrangement of thoracic, abdominal, and anal tufts of hair vary in different species and present characteristics of value. On either side of the eighth abdominal segment is a patch of scales varying greatly in arrangement and number and of much value in separating species. Respiration is by means of tracheæ which open at the apex of the so-called anal siphon, when it is present. In addition, there are also one or two pairs of tracheal gills which vary much in appearance in different species. On the ventral side of the anal siphon is a double row of flattened, toothed spines whose number and shape are likewise of some value in separating species. They constitute the comb or pecten. - Cross section of the larva of the browntail moth showing the tubercles bearing the poison hairs
- Cordylobia anthropophaga
- Conorhinus sanguisugus
- Conorhinus abdominalis
- Common Water Spider
The female lays eggs in a bubble, which, covered with a double layer of silk and deformed into a more or less flat bulb, is hung on a water plant or in the diver's bell and carefully monitored. - Common Tiger Beetle
Larvæ in Burrows. Two Other Species in Background. They are true children of the earth. The eggs are laid in the earth, and in the earth the grubs are hatched, and in the earth they spend their days, and in the earth they prepare their shrouds, and, wrapped therein, sleep their pupa-sleep through the long, dreary winter, and with the returning warmth of spring crawl out of their earthy chambers to run and sport on earth, seldom using their new-formed wings to fly away from their beloved mother. - Common Cockroach
(Blatta orientalis). a, female; b, male; c, side view of female; d, young. After Marlatt, Entom. Bull. 4, U.S. Dept. Agric. The young creature is hatched from the egg in a form closely resembling, on the whole, that of its parent, so that the term 'miniature adult' sometimes applied to it, is not inappropriate. The baby cockroach is known by its flattened body, rounded prothorax, and stiff, jointed tail-feelers or cercopods; the baby grasshopper by its strong, elongate hind-legs, adapted, like those of the adult, for vigorous leaping. - Colymbetes rufimanus - Larva
- Colymbetes rufimanus
- Cockroach-hunting wasps
Cockroach-hunting wasps. A, Dolichurus stantoni leading a nymph of Blattella lituricollis to her nest, c. X 4. B, Podium haematogastrum attaching her egg to an Epilampra sp. while on the side of a termite mound that contains the wasp's nest, c. X 1.6. C, Epilampra sp. parasitized by P. haematogastrum showing the wasp's egg attached to the right fore coxa, c. X 3.2. - Cockroach (Roach)
- Cockroach
A female cockroach, Periplaneta, with the dorsal exoskeleton removed, dissected to show the viscera. 1 Head 2 labrum 3 antenna, cut short 4 eye 5 crop 6 nervous system of crop 7 gizzard 8 hepatic caeca 9 mid-gut or mesenteron 10 Malpighian tubules 11 colon 12 rectum 13 salivary glands 14 salivary receptacle 15 brain 16 ventral nerve cord with ganglia 17 ovary 18 spermatheca 19 oviduct 20 genital pouch, in which the egg-cocoon is found 21 colleterial glands 22 anal cercus (From Latter. - Cockroach
Periplaneta orientalis, male. Side view. 1 Antenna 2 head 3 prothorax 4 anterior wing 5 soft skin between terga and sterna 6 sixth abdominal tergum 7 split portion of tenth abdominal tergum 8 cercianales 9 styles 10 coxa of third leg 11 trochanter 12 femur 13 tibia 14 tarsus 15,claws (From Kükenthal.) - Cockroach
Periplaneta orientalis, male Dorsal view. 1 Antenna 2 palp of first maxilla 3 prothorax 4 anterior wings 5 femur of second leg 6 tibia 7 tarsus 8 cerci anales 9 styles (From Kükenthal.) - Cimex lectularius
- Cicindela tuberculata - Larva
- Cicindela tuberculata
- Chætosoma scaritides
Chætosoma scaritides - Chrysomyia macellaria
- Chrysalis of Tomato Worm
- Chinch Bug
- Chiasognathus Grantii, upper view
Chiasognathus Grantii, upper view - Chiasognathus Grantii, under side
Chiasognathus Grantii, under side - Chiasognathus Grantii 2
- Chiasognathus Grantii
2 Chiasognathus Grantii, under side 3,4 Maxillae with lacinia and palpus 5 Mentumprocesses of labium and palpi, under view 6 Base of anterior femora 7 Mentum, labium, &c. upper view 8 Labium with processes amd palpi, lateral view - Centipede