| Rhizoglyphus | |
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| Rhizoglyphus echinopus | |
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| Genus: | Rhizoglyphus Claparédè, 1869 |
Rhizoglyphus is a genus of mites in the family Acaridae. [1] It has a worldwide distribution and is often associated with the bulbs, corms or tubers of plants. [2] [3]
Rhizoglyphus begin their lives as whitish, ellipsoidal eggs that are 0.12 mm long. These hatch into larvae, which are oval, white and have three pairs of legs. Larvae are 0.15-0.2 mm long on hatching and grow to 0.25 mm long. Larvae then develop into protonymphs, which are 0.4 mm long and (compared to larvae) gain an additional leg pair and two genital suckers. [2]
Under certain conditions such as high population density, protonymphs develop into deutonymphs (or hypopi), a quiescent stage that does not feed. This life stage is convex dorsally and flattened ventrally, brown in colour, 0.2-0.3 mm long, heavily sclerotised, lacks mouthparts and has a ventral sucker plate. The purpose of the deutonymph stage is to attach to insects and be carried to other bulbs (phoresis). Deutonymphs are resistant to starvation and desiccation during adverse conditions. [2] [4]
The tritonymph stage follows the protonymph (or deutonymph). Tritonymphs are about 0.5 mm long and have three or four genital suckers. They eventually develop into adults. [2]
Adults are 0.5-0.9 mm long, shiny, white and somewhat transparent, and have reddish brown appendages. Unlike tritonymphs, they have distinct genital apertures. [2] Some features which distinguish adult Rhizoglyphus from other mites are: 4 pairs of prodorsal setae and 12 pairs of dorsal hysterosomal setae, external vertical setae small/vestigial and situated about halfway along sides of prodorsal shield, supracoxal setae smooth, and tarsi I and II each with a proximal conical spine near bases of solenidion and famulus. [5]
The duration of the life cycle depends on Rhizoglyphus species, diet, temperature and relative humidity. At a temperature of 25 °C, it can be as short as 12.2 days for Rhizoglyphus robini and 13.9 days for R. echinopus. Adults live longer (for up to 121 days) at lower temperatures. Males tend to live twice as long as females in this genus. [2]
As noted previously, Rhizoglyphus deutonymphs ride on other, larger arthropods for dispersal. They have been collected from scarab beetles, weevils, various flies and fleas. [4]
Rhizoglyphus feed on a range of ornamental (e.g. Dahlia , Eucharis , Gladiolus , Hyacinthus , Iris, lily, Narcissus, orchid, tulip) and crop plants (e.g. barley, carrot, garlic, onion, potato, sweet potato, taro). [3] [5] While underground plant parts are most commonly attacked, the mites have also been collected from leaves, stems and seeds. [3] [4]
Rhizoglyphus secrete an alarm pheromone from opisthonotal glands. This pheromone has neryl-formate as its main component and citral and α-acaridial as minor components. Its secretion triggers escape behaviour in other mites and it may be involved in mite defense against predators. Citral and α-acaridial also have antifungal activity. [4]
These mites also have a range of cuticular chemicals. Hexyl rhizoglyphinate is another antifungal, while the roles of other chemicals remain unknown. [4]
As noted previously, Rhizoglyphus feed on a range of plants. Infested bulbs may rot and fail to produce new growth, or new growth may be discoloured, stunted and distorted. In tulips, Rhizoglyphus may enter prematurely opened buds and cause bud necrosis. [2]
Bulbs that are damaged or infested with Fusarium fungus are more vulnerable to attack. [4]
Due to their pest status, these mites are classified as quarantine species by many countries such as Australia and New Zealand. [5]
Rough handling of bulbs should be avoided as this can cause damage that allows Rhizoglyphus to enter. Keeping bulbs dry also generally prevents them from being attacked, since the mites cannot withstand drought. [2]
A range of pesticides have been used, but Rhizoglyphus are resistant to a number of pesticides and there is concern about pesticides affecting non-target species. [4]
There has been research on biological control of this genus of mites. Most of this has involved predatory mites, [4] but entomopathogenic nematodes have also been considered. [6]
Hypoaspis is a genus of mites in the family Laelapidae.
The Acaridae are a family of mites in order Sarcoptiformes.
Astigmatina is a clade of mites in the superorder Acariformes. Astigmata has been ranked as an order or suborder in the past, but was lowered to the unranked clade Astigmatina of the clade Desmonomatides in the order Sarcoptiformes. Astigmatina is now made up of the two groups Acaridia and Psoroptidia, which have been suborders of the order Astigmata in the past. Astigmatina contains about 10 superfamilies and 76 families under Acaridia and Psoroptidia.
Eriophyoidea are a superfamily of herbivorous mites. All post-embryonic instars lack the third and fourth pairs of legs, and the respiratory system is also absent.
The Raphignathoidea is a superfamily of the Acari (mite) order Trombidiformes, comprising 1087 species in 62 genera and 12 families.
Trombidiidae, also known as red velvet mites, true velvet mites, or rain bugs, are small arachnids found in plant litter and are known for their bright red color.
Trombiculidae, commonly referred to in North America as chiggers and in Britain as harvest mites, but also known as berry bugs, bush-mites, red bugs or scrub-itch mites, 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 cause "intense irritation" or "a wheal, usually with severe itching and dermatitis".
Lorryia formosa, commonly known as the yellow mite or the citrus yellow mite, is a species of acariform mite. They are in the subfamily Tydeinae of the family Tydeidae. Commonly found on the foliage of citrus trees around the world, Lorryia formosa also associates with a variety of other plant types. The life cycle includes six discrete stages of development, and the lifespan averages about 37 days. The females of the species use an asexual form of reproduction where the growth and development of embryos occurs without fertilization by a male, a process called thelytoky.
Parasitengona is a group of mites, variously ranked as a hyporder or a cohort, between the taxonomic ranks of order and family.
The Laelapidae are a family of mites in the order Mesostigmata. The family is also referred to in the literature as Laelaptidae, which may be the correct spelling.
Cosmoglyphus is a genus of mites in the family Acaridae.
Macrochelidae is a family of mites in the order Mesostigmata.
Ascidae is a family of mites in the order Mesostigmata.
Brevipalpus phoenicis, also known as the false spider mite, red and black flat mite, and in Australia as the passionvine mite, is a species of mite in the family Tenuipalpidae. This species occurs globally, and is a serious pest to such crops as citrus, tea, papaya, guava and coffee, and can heavily damage numerous other crops. They are unique in having haploid females, a condition caused by a bacterium that change haploid males into females.
Phenopelopidae is a family of oribatid mites in the order Sarcoptiformes. As of 2018, there were 4 genera and 106 species known in this family.
Halacaridae is a family of meiobenthic mites found in marine, brackish, and freshwater habitats around the world. It includes more than 1100 described species belonging to 64 genera It is the largest marine radiation of arachnids.
Roubikia is a genus of bee-associated mites occurring in the neotropics. They are mutualists or commensals, and feed on fatty acids from floral oils and most likely on fungi. The type species is Chaetodactylus panamensis.
Tyrophagus longior is a mite in the family Acaridae.
Aleuroglyphus ovatus, commonly known as brown-legged mite or brownlegged grain mite, is a species of mite in the family Acaridae. It is a cosmopolitan pest of grain.
Suidasia is a genus of mites in the family Suidasiidae and clade Astigmatina.
| Authority control databases: National |
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