Clubroot is a common disease of cabbages, broccoli, cauliflower, Brussels sprouts, radishes, turnips, stocks, wallflowers and other plants of the family Brassicaceae (Cruciferae). It is caused by Plasmodiophora brassicae, which was once considered a slime mold but is now put in the group Phytomyxea. It is the first phytomyxean for which the genome has been sequenced. It has as many as thirteen races. Gall formation or distortion takes place on latent roots and gives the shape of a club or spindle. In the cabbage such attacks on the roots cause undeveloped heads or a failure to head at all, followed often by decline in vigor or by death. It is an important disease, affecting an estimated 10% of the total cultured area worldwide.
Cecidomyiidae is a family of flies known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. Cecidomyiidae are very fragile small insects usually only 2–3 mm (0.079–0.118 in) in length; many are less than 1 mm (0.039 in) long. They are characterised by hairy wings, unusual in the order Diptera, and have long antennae. Some Cecidomyiids are also known for the strange phenomenon of paedogenesis in which the larval stage reproduces without maturing first. In some species, the daughter larvae consume the mother, while in others, reproduction occurs later on in the egg or pupa.
Diplotaxis tenuifolia is a species of flowering plant in the mustard family known by the common name perennial wall-rocket. It is native to Europe and western Asia, where it grows on disturbed ground and roadsides, and it can now be found throughout much of the temperate world where it has naturalized. In recent years it has increasingly been cultivated to produce salad leaves, which are marketed as wild rocket in Britain or arugula in the US. It is easily confused with garden rocket, which has similar uses.
Sciaroidea is a superfamily in the infraorder Bibionomorpha. There are about 16 families and more than 15,000 described species in Sciaroidea. Most of its constituent families are various gnats.
Black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Xcc), is considered the most important and most destructive disease of crucifers, infecting all cultivated varieties of brassicas worldwide. This disease was first described by botanist and entomologist Harrison Garman in Lexington, Kentucky, US in 1889. Since then, it has been found in nearly every country in which vegetable brassicas are commercially cultivated.
Orseolia oryzae, also called the Asian rice gall midge, is a species of small fly in the family Cecidomyiidae. It is a major insect pest of rice. The damage to the crop is done by the larvae which form galls commonly known as "silver shoots" or "onion shoots". The rice plant is stunted and the seed heads fail to develop.
Contarinia quinquenotata is a small midge which infests the flower buds of Hemerocallis, causing the buds to swell, remain closed and rot. It is a pest in several parts of the world. It is known by the common names of daylily gall midge and hemerocallis gall midge.
Contarinia is a genus of midges, small flies in the family Cecidomyiidae. There are over 300 described species in the genus.
A gnat is any of many species of tiny flying insects in the dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. They can be both biting and non-biting. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. Certain universities and institutes also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".
Asphondylia is a cosmopolitan genus of gall midges in the family Cecidomyiidae. All species in this genus induce galls on plants, especially on flowers and flower buds. There are over 300 described species in Asphondylia, with many more likely to be discovered and described, especially in the southern hemisphere.
Rhopalomyia anthophilathe Downy Flower Gall Midgeis a species of gall midges, insects in the family Cecidomyiidae. It induces galls on the host Solidago altissima across much of North America.
Rabdophaga rigidae, the willow beaked-gall midge, is a species of gall midge in the family Cecidomyiidae. It is found across North America. Some sources state that it is also present in parts of eastern Asia including Japan; however, a 2006 study shows that the Asian populations likely represent a separate species: Rabdophaga salicivora.
Contarinia negundinis, known generally as boxelder gall midge, is a species of gall midges in the family Cecidomyiidae. Other common names include the boxelder bud gall midge and boxelder leaf gall midge. It is the only North American species that enters diapause during the pupal stage of development.
Contarinia virginianiae, known as chokecherry midge or chokecherry gall midge, is a species of gall midges in the family Cecidomyiidae. Its host is the chokecherry Prunus virginiana.
Polystepha pilulae, the oak leaf gall midge, is a species of gall midge in the family Cecidomyiidae. It is found in eastern North America.
Geromyia penniseti, the millet grain midge, is a species of gall midge in the family Cecidomyiidae. It is found in Africa and South Asia. During the rainy season, it feeds on the developing grains of pearl millet plants.
Stenodiplosis sorghicola, the sorghum midge, is a species of gall midge in the family Cecidomyiidae. It is a pest of millets. The species is native to Africa and is also found in India. During the rainy season, it feeds on the developing grains of pearl millet plants.
Mayetiola thujae, the redcedar cone midge, is a species of gall midge that infects western redcedar cones.
Synopeas myles is a platygastrid parasitoid of Contarinia nasturtii, that, like its host, is native to Europe. It has been considered as a potential biological pest control in North America, where C. nasturtii is invasive.
