Toxicodendron is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (toxikos), meaning "poison," and δένδρον (dendron), meaning "tree". The best known members of the genus in North America are poison ivy (T. radicans), practically ubiquitous throughout most of eastern North America, and western poison oak, similarly ubiquitous throughout much of the western part of the continent.
Toxicodendron radicans, commonly known as eastern poison ivy or poison ivy, is an allergenic Asian and Eastern North American flowering plant in the genus Toxicodendron. The species is well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch it. The rash is caused by urushiol, a clear liquid compound in the plant's sap. The species is variable in its appearance and habit, and despite its common name, it is not a true ivy (Hedera), but rather a member of the cashew and pistachio family (Anacardiaceae). T. radicans is commonly eaten by many animals, and the seeds are consumed by birds, but poison ivy is most often thought of as an unwelcome weed. It is a different species from western poison ivy, Toxicodendron rydbergii, which has similar effects.
Galls or cecidia are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. The study of plant galls is known as cecidology.
Mites are small arachnids.
Sarcoptes scabiei or the itch mite is a parasitic mite that burrows into skin and causes scabies. The mite is found in all parts of the world. Humans are not the only mammals that can become infected. Other mammals, such as wild and domesticated dogs and cats as well as ungulates, wild boars, bovids, wombats, koalas, and great apes are affected.
Rhus typhina, the staghorn sumac, is a species of flowering plant in the family Anacardiaceae, native to eastern North America. It is primarily found in southeastern Canada, the northeastern and midwestern United States, and the Appalachian Mountains, but it is widely cultivated as an ornamental throughout the temperate world.
Eriophyidae is a family of more than 200 genera of mites, which live as plant parasites, commonly causing galls or other damage to the plant tissues and hence known as gall mites. About 3,600 species have been described, but this is probably less than 10% of the actual number existing in this poorly researched family. They are microscopic mites and are yellow to pinkish white to purplish in color. The mites are worm like, and have only two pairs of legs. Their primary method of population spread is by wind. They affect a wide range of plants, and several are major pest species causing substantial economic damage to crops. Some species, however, are used as biological agents to control weeds and invasive plant species.
Fuchsia magellanica, commonly known as the hummingbird fuchsia or hardy fuchsia, is a species of flowering plant in the evening primrose family Onagraceae, native to the lower Southern Cone of southern South America.
Cecidophyopsis ribis is an eriophyid mite which is best known for being a plant parasite, a pest of Ribes species, the genus that includes gooseberries and blackcurrants.
Aceria chondrillae is a gall forming deuterogynous, eriophyid (mite) often used as a biological control of the noxious weed, Chondrilla juncea, a highly competitive herbaceous perennial composite found in Europe, Asia, Australia and North America.
The camas pocket gopher, also known as the camas rat or Willamette Valley gopher, is a rodent, the largest member in the genus Thomomys, of the family Geomyidae. First described in 1829, it is endemic to the Willamette Valley of northwestern Oregon in the United States. The herbivorous gopher forages for vegetable and plant matter, which it collects in large, fur-lined, external cheek pouches. Surplus food is hoarded in an extensive system of tunnels. The dull-brown-to-lead-gray coat changes color and texture over the year. The mammal's characteristically large, protuberant incisors are well adapted for use in tunnel construction, particularly in the hard clay soils of the Willamette Valley. The gophers make chattering sounds with their teeth; males and females make purring sounds when they are together, and the young make twittering sounds. Born toothless, blind and hairless, the young grow rapidly before being weaned at about six weeks of age.
Pyemotes herfsi, also known as the oak leaf gall mite or itch mite, is an ectoparasitic mite identified in Western Canada in 1923 and subsequently found in India, Asia, and the United States. The mite parasitizes a variety of insect hosts and bites humans, causing red, itchy, and painful wheals (welts). The mites are barely visible, measuring about 0.2-0.8 millimeters; their great reproductive potential, small size, and high capacity for dispersal by wind make them difficult to control or avoid.
Rhus glabra, the smooth sumac, is a species of sumac in the family Anacardiaceae, native to North America, from southern Quebec west to southern British Columbia in Canada, and south to northern Florida and Arizona in the United States and Tamaulipas in northeastern Mexico.
Trombiculidae are a family of mites. Chiggers are often confused with jiggers - a type of flea. Several species of Trombiculidae in their larva stage bite their animal or human host and by embedding their mouthparts into the skin causing "intense irritation" or "a wheal, usually with severe itching and dermatitis",
Melaphis rhois is an aphid species first identified by Asa Fitch in 1866. Known as the staghorn sumac aphid, it is the only species in the genus Melaphis. It is a type of woolly aphid and one of the few aphids that induce the formation of galls.
Aculops fuchsiae, commonly known as fuchsia gall mite, is a species of mite in the family Eriophyidae. It feeds on Fuchsia plants, causing distortion of growing shoots and flowers. It is regarded as a horticultural pest.
Tetraschininae is a subfamily of the chalcid wasp family Eulophidae. It is one of the largest subfamilies of the Eulophidae containing over 100 genera and nearly 3,000 species. The species of the family Tetrastichinae are found in almost any type of terrestrial habitat and have a worldwide distribution, except Antarctica. They show a varied biology and hosts for Tetraschine wasps have been identified from over 100 different insect families, across 10 different orders and they have also been recorded as being parasitoids on nematodes, mites and spiders' eggs. Some species are even phytophagous, while others are inquilines and yet others are gall formers.
Aculops tetanothrix, also known as the willow gall mite, is a species of mite that belongs to the family Eriophydae. The mite is yellow, with brown or sometimes orange.
Aculops is a genus of mites that belongs to the family Eriophyidae that live as plant parasites. Some species, such as Aculops lycopersici, are severe crop or ornamental pests, while Aculops ailanthii is being considered as biocontrol for the extremely invasive tree-of-heaven in North America. Very little is known about this genus, with new species constantly being discovered even in well covered regions such as New Zealand.
Aculops ailanthii, the Ailanthus leafcurl mite, is a species of eriophyid mite that infects trees-of-heaven. Very little is known about this species. A. ailanthii has been proposed as a potential biocontrol alongside Ailanthus webworms and Mimosa wilt in North America, where Ailanthus is a severe invasive.
Closeup of the galls formed by A. rhois
