"A genus of parasitic Hymenoptera, of the family Braconidæ."-Whitney, 1902

Aleiodes

"A genus of parasitic Hymenoptera, of the family Braconidæ."-Whitney, 1902

An apple blossom, just right to spray for coddling moth.

Apple blossom

An apple blossom, just right to spray for coddling moth.

A young apple blossom beginning to grow, almost too late to spray for coddling moth.

Growing apple

A young apple blossom beginning to grow, almost too late to spray for coddling moth.

"Diagrams of bladder-worms. I. The ordinary Cysticercus type with one head (H.). II. The Coenurus type, with many heads. III. The Echinococcus type, with many heads, and with brood capsules producing many heads." -Thomson, 1916

Bladder-Worms

"Diagrams of bladder-worms. I. The ordinary Cysticercus type with one head (H.). II. The Coenurus type,…

"The flatheaded borer, the larva." — Goff, 1904

Borer Insect

"The flatheaded borer, the larva." — Goff, 1904

"The flatheaded borer, the pupa." — Goff, 1904

Borer Insect

"The flatheaded borer, the pupa." — Goff, 1904

"The flatheaded borer, the perfect beetle." — Goff, 1904

Borer Insect

"The flatheaded borer, the perfect beetle." — Goff, 1904

"The Cheese-mite, <em>Acarus domesticus</em>, and others are parasitic upon or beneath the skin of man and other animals." &mdash; Goodrich, 1859

Cheese-mite

"The Cheese-mite, Acarus domesticus, and others are parasitic upon or beneath the skin of man…

Flabellifera are a type of isopod. Their bodies end in a tail fan, made by the last pair of appendages and the telson (end piece). This species is parasitic, sharing the title of 'fish lice' with other certain parasitic copepods.

Cirolana Microphthalmia

Flabellifera are a type of isopod. Their bodies end in a tail fan, made by the last pair of appendages…

"Two conidia joined with one secondary conidium."&mdash;Finley, 1917

Joined conidia

"Two conidia joined with one secondary conidium."—Finley, 1917

Also known as fish lice, this is a species of copepod, a parasitic crustacean. "Female of Chondracathus gibbosus, enlarged; and example of the crustaceous Epizoa. A, lateral view." -Whitney, 1911

Copepod

Also known as fish lice, this is a species of copepod, a parasitic crustacean. "Female of Chondracathus…

Also known as fish lice, this is a species of copepod, a parasitic crustacean. "Female of Chondracathus gibbosus, enlarged; and example of the crustaceous Epizoa. B, ventral view; a, head; b, c, appendages; d, d, mediodorsal processes; e, e, medioventral processes; f, i, h, lateral processes; g, ovisacs; k, terminal segment; l, minute male lodged in vulva of female; m, n, mediodorsal ovarian tubes; p, lateral ovarian tubes; o, o, oviduct; 2, 3, antennules; 4, 5, 6, antennae, gnathites." -Whitney, 1911

Copepod

Also known as fish lice, this is a species of copepod, a parasitic crustacean. "Female of Chondracathus…

The Sphaeria sinensis a cordycep, a parasitic fungus. "The right hand figure represents the manner in which it is made up for sale." -Lindley, 1853

Cordycep

The Sphaeria sinensis a cordycep, a parasitic fungus. "The right hand figure represents the manner in…

The Sphaeria Robertsii a cordycep, a parasitic fungus "growing from the caterpillar of a New Zealand moth called Hepialus verescens." -Lindley, 1853

Cordycep

The Sphaeria Robertsii a cordycep, a parasitic fungus "growing from the caterpillar of a New Zealand…

The pea crab is a small crab in the family Pinnotheridae that lives symbiotically in oysters, clams, mussels and other species of bivalves. The crab is usually about the size of a pea but can grow as large as a small walnut. It is also commonly known as the oyster crab. Females have a large tail flap that is used to cover eggs attached to the bodies when they are breeding, adding to the spherical appearance.

Pea Crab

The pea crab is a small crab in the family Pinnotheridae that lives symbiotically in oysters, clams,…

"A parasite sometimes present in the human hair follicles." &mdash;Davison, 1906

Demodex Folliculorum

"A parasite sometimes present in the human hair follicles." —Davison, 1906

"A low story between two others of greater height, especially one so treated architecturally that from the exterior it appears to form a single story with the one below it ... Part of House on Boulevard Malesherbes, Paris. E, E, entresol." -Whitney, 1911

Entresol

"A low story between two others of greater height, especially one so treated architecturally that from…

the flea has a curios apparatus for sucking blood, which is very beautiful as examined with a microscope (Hooker, 1882).

Flea

the flea has a curios apparatus for sucking blood, which is very beautiful as examined with a microscope…

Fleas are parasites. That is any plant or animal which feeds upon another living plant or animal without destroying it.

Flea

Fleas are parasites. That is any plant or animal which feeds upon another living plant or animal without…

Fleas are parasites. That is any plant or animal which feeds upon another living plant or animal without destroying it.

Flea

Fleas are parasites. That is any plant or animal which feeds upon another living plant or animal without…

Adult human flea, magnified twenty-two times.

Adult Human Flea

Adult human flea, magnified twenty-two times.

The human flea (Pulex irritans) is a parasitic insect that actually has several hosts despite its name.

Human Flea

The human flea (Pulex irritans) is a parasitic insect that actually has several hosts despite its name.

The human flea (Pulex irritans) is a parasite in the the Siphonaptera order of fleas.

Human Flea

The human flea (Pulex irritans) is a parasite in the the Siphonaptera order of fleas.

"After attaching themselves to the walls of the stomach, the botfly larva are nourished by the blood and lymph of the host until the following spring, when they pass on through the canal, burrow through the ground, and transform into the adult about two weeks later." &mdash; Davison, 1906

Botfly Larva

"After attaching themselves to the walls of the stomach, the botfly larva are nourished by the blood…

"After attaching themselves to the walls of the stomach, the botfly larva are nourished by the blood and lymph of the host until the following spring, when they pass on through the canal, burrow through the ground, and transform into the adult about two weeks later." &mdash; Davison, 1906

Mature Botfly

"After attaching themselves to the walls of the stomach, the botfly larva are nourished by the blood…

The Sheep Ked (Melophagus ovinus) is a wingless louse fly that is a parasite to sheep.

Sheep Ked

The Sheep Ked (Melophagus ovinus) is a wingless louse fly that is a parasite to sheep.

"The Ox-fly, Oestrus bovis, is three-forths of an inch long, and lays its eggs in the skin of young cattle, producing a swelling which supprates and forms a purulent humor, on which the larvae feed." &mdash; Goodrich, 1859

Ox Fly

"The Ox-fly, Oestrus bovis, is three-forths of an inch long, and lays its eggs in the skin of young…

They are rich colored insects, very active in the hottest sunshine and capable of rolling themselves up into a ball.

Ruby Tailed Fly

They are rich colored insects, very active in the hottest sunshine and capable of rolling themselves…

A gadfly, or Bot-fly, that lays its eggs on horses. After these eggs hatch on the skin, the larvae bore into the skin and create tumors ('warbles') beneath it. When fully fed, they leave their host and drop to the ground, bury themselves, and, after pupation, emerge as flies. This illustration is enlarged, and also shows the larvae.

Gadfly of Horse

A gadfly, or Bot-fly, that lays its eggs on horses. After these eggs hatch on the skin, the larvae bore…

Galls on leaf of rose. The location of a parasite is often marked by swellings of peculiar and fantastic or beautiful forms (galls) that grow on leaves and stems.

Gall

Galls on leaf of rose. The location of a parasite is often marked by swellings of peculiar and fantastic…

Galls on leaf of rose. The location of a parasite is often marked by swellings of peculiar and fantastic or beautiful forms (galls) that grow on leaves and stems.

Gall

Galls on leaf of rose. The location of a parasite is often marked by swellings of peculiar and fantastic…

Galls on stem of grape. The location of a parasite is often marked by swellings of peculiar and fantastic or beautiful forms (galls) that grow on leaves and stems.

Gall

Galls on stem of grape. The location of a parasite is often marked by swellings of peculiar and fantastic…

This spongy gall is found on various species of roses, and is produced by several insects as receptacles for their eggs. the larvae then feed upon the juices of the plant.

Gall

This spongy gall is found on various species of roses, and is produced by several insects as receptacles…

"Woolly Oak-gall, produced by Cynips Quercus ramuli." -Lindley, 1853

Gall Wasp

"Woolly Oak-gall, produced by Cynips Quercus ramuli." -Lindley, 1853

"Galls on the leaf of an Ochnaceous plant." -Lindley, 1853

Galls

"Galls on the leaf of an Ochnaceous plant." -Lindley, 1853

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of…

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of…

"Gregarina, free pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, free pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans,…

"Gregarina of Earthworm, encysted. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina Encysted

"Gregarina of Earthworm, encysted. GREGARINIDAE. A family or other major group of endoplastic protozoans,…

"Gregarina of Earthworm. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina of Earthworm

"Gregarina of Earthworm. GREGARINIDAE. A family or other major group of endoplastic protozoans, having…

"Gregarina, their free amoebiform contents. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Amoebiform Gregarina

"Gregarina, their free amoebiform contents. GREGARINIDAE. A family or other major group of endoplastic…

"The ichineumons, with long ovipositors, as the European species, <em>Ichneumon manifestator</em>, seek the burrows of the wood-boring insects, whose larva they are enabled to reach by means of this organ. Each species usually infests a particulat species of insect; and, singular as it may appear, many of these parasitic larvae are again preyed upon by others, whose parents are directed by an unerring instinct to the selection of the proper position for the nourishment of their arguement." &mdash; Goodrich, 1859

Ichneumon

"The ichineumons, with long ovipositors, as the European species, Ichneumon manifestator, seek…

Ichneumon flies are solitary insects, and most are parasitoids&mdash;the larvae feeding on or in another insect which finally dies. As with all hymenopterans, ichneumons are closely related to ants and bees. The female finds a host and lays an egg on, near, or inside the host's body. Upon hatching, the larval ichneumon feeds either externally or internally, killing the host when they themselves are ready to pupate. The large ichneumon fly (Thakessa), with long flexable ovipositor. The various parts of ths ovipositor are spread aapart in the figure; naturally they lie together to form a single piercing organ.

Ichneumon Fly

Ichneumon flies are solitary insects, and most are parasitoids—the larvae feeding on or in another…

Ichneumon flies are solitary insects, and most are parasitoids&mdash;the larvae feeding on or in another insect which finally dies. As with all hymenopterans, ichneumons are closely related to ants and bees. The female finds a host and lays an egg on, near, or inside the host's body. Upon hatching, the larval ichneumon feeds either externally or internally, killing the host when they themselves are ready to pupate. The large ichneumon fly (Thakessa), with long flexable ovipositor, boring to deposit eggs.

Ichneumon Fly

Ichneumon flies are solitary insects, and most are parasitoids—the larvae feeding on or in another…

Ichneumon flies deposit their eggs upon the bodies of other insects and larva. The larva live on the interior of their host.

Ichneumon Fly

Ichneumon flies deposit their eggs upon the bodies of other insects and larva. The larva live on the…

Entoniscus parasites is a parasitic isopod that feeds off and eventually replaces the tongues of fish and crabs.

Parasitic Isopod

Entoniscus parasites is a parasitic isopod that feeds off and eventually replaces the tongues of fish…

"The animals belonging to this order, of which the <em>Common Leech</em> is a familiar example, are characterized by the total deficiency of any lateral appendages, their motions being effected by undulations of the body while swimming, or by the alternate attachment of the sucking discs with which the two extremities of their bodies are usually furnished." &mdash; Goodrich, 1859

Leech

"The animals belonging to this order, of which the Common Leech is a familiar example, are…

Head lice are parasites. That is any plant or animal which feeds upon another living plant or animal without destroying it.

Head Louse

Head lice are parasites. That is any plant or animal which feeds upon another living plant or animal…

"A genus of insects, the type of a very numerous family, which forms the order Parasita or Auoplura. The body is flattened, almost transparent; the segments both of the thorax and abdomen very distinct; the mouth is small and tubular, enclosing a sucker; there are no wings; the legs are short, and are terminated by a claw adapted for taking hold of hairs or feathers. The eyes are simple, one or two on each side of the head. All the species are small, and live parasitically, on human beings, terrestrial mammalia, and birds." &mdash; Chambers, 1881

Magnified Louse

"A genus of insects, the type of a very numerous family, which forms the order Parasita or Auoplura.…

A small biting insect. Usually cured by an ointment

Crab Louse

A small biting insect. Usually cured by an ointment

"A common dipterous insect, which feeds upon the blood of sheep and lambs."&mdash;Finley, 1917

Sheep Louse

"A common dipterous insect, which feeds upon the blood of sheep and lambs."—Finley, 1917

"Wingless female, with a from which a parasite escaped." &mdash; Davison, 1906

Wheat Plant Louse

"Wingless female, with a from which a parasite escaped." — Davison, 1906

"A genus of small parasitical shrubs of the natural order Loranthaceae. This order is exogenous, and contains more than 400 known species, mostly tropical and parasites." &mdash; Chambers, 1881

Mistletoe

"A genus of small parasitical shrubs of the natural order Loranthaceae. This order is exogenous, and…

The follicle mite or Demodex.

Follicle Mite

The follicle mite or Demodex.

The itch mite or Sarcoptes scabiei.

Itch Mite

The itch mite or Sarcoptes scabiei.

Mosquitos are parasitic insects that suck blood from humans and other mammals. They are known to spread malaria and other diseases.

Mosquito

Mosquitos are parasitic insects that suck blood from humans and other mammals. They are known to spread…

"Diagram of the structure of a male Nematode. M., mouth; OE., oesophogus; GA., nerve ring; B., bulb at lower end of fore-gut; G., mesenteron; SP., spine with sheath; A., anus; D., ejaculatory duct; VS., seminal vesicle; T., testis; ET., longitudinal excretory tube, cut short; EP., excretory pore." -Thomson, 1916

Nematode

"Diagram of the structure of a male Nematode. M., mouth; OE., oesophogus; GA., nerve ring; B., bulb…

"Diagrammatic longitudinal section of a Nemertean (Amphiporum lactifloreus), dorsal view. p.p., Proboscis pore; b., brain giving off the lateral nerve-cords (n.); po., oesophageal pocket; p., proboscis lying within its sheath; st., stilet of proboscis; m., retractor muscles of proboscis; g., gut shown in outline at the sides of proboscis; e., the three main, longitudinal blood vessels, which unite both anteriorly and posteriorly." -Thomson, 1916

Nemertea

"Diagrammatic longitudinal section of a Nemertean (Amphiporum lactifloreus), dorsal view. p.p., Proboscis…

An ear of smutted oats.

Smutted oats

An ear of smutted oats.

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and walks on it until it finds a joint. It then molts, injecting its soft body into the crab while its shell falls off. The Sacculina grows in the crab, emerging as a sac, known as an externa, on the underside of the crab's rear thorax, where the crab's eggs would be incubated.

Crustacean Parasite

Sacculina is a genus of barnacles that parasitize crabs. The female Sacculina larva finds a crab and…