Phytoseiidae

The family Phytoseiidae contains these subfamilies:{{harv|Zicha|2004}}

• Amblyseiinae Muma, 1961
• Phytoseiinae Berlese, 1916
• Typhlodrominae Scheuten, 1857

Phytoseiid eggs can be found along the vein of the bottom side of a leaf. They are oblong and translucent white.{{Cite web|title=Predatory Mites {{!}} University of Maryland Extension|url=https://extension.umd.edu/resource/predatory-mites|access-date=2021-12-07|website=extension.umd.edu}}

The larvae of these mites range from translucent white to tan in colour. They are tiny and oval in shape and size, have six legs, and are wingless. Nymphs look similar to larvae, with the exception of being slightly larger and having eight legs.

Adult phytoseiids are less than 0.5 mm in size, pear-shaped, wingless, and have eight legs. They are translucent white, but turn a pale tan, orange/red, or green after feeding.

Developmental rate is species-specific, ranging from less than a week to four weeks, with temperature and diet affecting the rate.

The body of Phytoseiidae is divided into two parts: the gnathosoma (anterior) and idiosoma (posterior). The gnathosoma includes chelicerae, sensorial palps, and a stylophore. Males have an added feature- a spermatodactyl to transfer spermatophore to females.

Phytoseiid mites are best known as predators of small arthropods and nematodes, but many species are also known to feed on fungi, plant exudates, and pollen.

Scientists have proposed classifications of the Phytoseiidae based on their food sources. In the most current version, developed in 2013, phytoseiids are grouped into four types.{{Cite journal|url = http://zoobank.org/References/9FF82B60-CFB0-4B48-AD09-316818CE06C8|title = Revision of the lifestyles of phytoseiid mites (Acari: Phytoseiidae) and implications for biological control strategies|last = McMurtry|first = James|date = December 24, 2013|journal = Systematic & Applied Acarology|volume = 18|issue = 4|pages = 297|doi = 10.11158/saa.18.4.1|s2cid = 55807023|access-date = October 20, 2015|doi-access = free|hdl = 11336/84660|hdl-access = free}}

• Type I includes species that are specialized mite predators, with three subgroups determined by the type of prey.
• Type II includes species that feed on tetranychid mites, meaning mites that are capable of spinning webs.
• Type III phytoseiids are classified as generalist predators. They can feed on mites of many families, as well as thrips, whiteflies, nematodes, and even pollen. Type III is further subdivided into five groups based on the habitat where the phytoseiids can be found.
• Type IV phytoseiids rely on pollen as their primary food source. These species can also act as generalist predators, but they are most successful when feeding on pollen.

Mites are commonly associated as a whole with parasitic mites like scabies, chiggers, and bird mites,{{Cite web|title=Parasitic Mites of Humans {{!}} Entomology|url=https://entomology.ca.uky.edu/ef637|access-date=2021-12-07|website=entomology.ca.uky.edu}} or common house dust mites, giving them a negative reputation. However, the family Phytoseiidae provides benefits for agriculture by feeding on pests. Insecticides are often used when handling agricultural pests, though to attract and conserve phytoseiid mites, broad-spectrum insecticides are to be avoided. Phytoseiidae can be used as biological control agents in place of toxic chemicals.

Phytoseiids are an important natural predator of the spider mite. When phytoseiid populations decline, spider mites can severely damage commercial crops. Since World War II, spider mite (tetranychid) populations have

increased due to the use of synthetic pesticides.{{Cite journal|title = The Ecology of Tetranychid Mites and Their Natural Control|journal = Annual Review of Entomology|date = 1969-01-01|pages = 125–174|volume = 14|issue = 1|doi = 10.1146/annurev.en.14.010169.001013|first1 = C. B.|last1 = Huffaker|first2 = M. van de|last2 = Vrie|first3 = J. A.|last3 = McMurtry}} The reason pesticides have increased spider mite populations remains mysterious to scientists, but it has spurred an interest in phytoseiids as biological control agents. So far, research has shown that phytoseiids are effective control agents in both their native environments and open-field vegetable crops.{{Cite journal|title = Management of insect and mite pests with predaceous mites in open-field vegetable crops|journal = Israel Journal of Entomology|date = 2018-06-28|pages = 83–111|volume = 48|issue = 2|doi = 10.5281/zenodo.1299520|first1 = Ph.A.|last1 = Stansly| first2 = J.A.|last2 = Castillo| first3 = J.A.|last3 = Tansey| first4 = B.C.|last4 = Kostyk}}

Phytoseiid species that act as biological control agents are influenced by the availability of their prey. Phytoseiids can postpone or delay egg production during periods when prey are scarce. This allows them to have a longer lifespan and likely serves as an adaptation to environments where prey availability is variable.{{Cite journal|title = The profit of senescence in phytoseiid mites|journal = Oecologia|date = 1979-12-01|issn = 0029-8549|pages = 87–90|volume = 44|issue = 1|doi = 10.1007/BF00346403|pmid = 28310469|first1 = Leo H. M.|last1 = Blommers|first2 = Rolf C. M. van|last2 = Arendonk| bibcode=1979Oecol..44...87B |s2cid = 27696609}} In addition to being able to delay reproduction, phytoseiids are also capable of rapid reproduction when prey is readily available. They reproduce more when

prey availability is high, which increases their effectiveness as biological control agents. When prey availability increases, females lay more eggs, and more healthy offspring are produced during reproductive periods. In addition, when prey availability increases, the Phytoseiidae kill more prey during reproductive cycles, and the ratio of prey killed to eggs laid increases.{{Cite journal|title = Influence of prey availability on reproduction and prey consumption of Phytoseiulus persimilis, Amblyseius californicus and Metaseiulus occidentalis (Acarina: Phytoseiidae)|journal = International Journal of Acarology|date = 1982-06-01|issn = 0164-7954|pages = 85–89|volume = 8|issue = 2|doi = 10.1080/01647958208683283|first1 = D. D.|last1 = Friese|first2 = F. E.|last2 = Gilstrap}}

Wolbachia, a parasitic bacterial genus that affects a vast array of arthropod species such as Drosophila simulans, is common in the Phytoseiidae. It affects gender determination and reproduction of its hosts, making it a powerful agent of evolution.{{Cite journal|title = Evolutionary consequences of Wolbachia infections|journal = Trends in Genetics|date = 2003-04-01|issn = 0168-9525|pmid = 12683975|pages = 217–223|volume = 19|issue = 4|doi = 10.1016/S0168-9525(03)00024-6|first1 = Sylvain|last1 = Charlat|first2 = Gregory D. D.|last2 = Hurst|first3 = Hervé|last3 = Merçot}} Wolbachia species have been detected in many species of Phytoseiidae, both in the field and in the lab.{{Cite journal|title = Wolbachia in a Predator–Prey System: 16S Ribosomal Dna Analysis of Two Phytoseiids (Acari: Phytoseiidae) and Their Prey (Acari: Tetranychidae)|journal = Annals of the Entomological Society of America|date = 1996-05-01|issn = 0013-8746|pages = 435–441|volume = 89|issue = 3|doi = 10.1093/aesa/89.3.435|first1 = Denise L.|last1 = Johanowicz|first2 = Marjorie A.|last2 = Hoy|doi-access = free}} Although most research focuses on Wolbachia in germ line tissues, the bacteria can also be found in somatic tissues. Wolbachia's main method of spreading is to be passed down through the generations in germline tissues, but it is also capable of being transferred horizontally.{{Cite journal|title = Wolbachia infections are distributed throughout insect somatic and germ line tissues|journal = Insect Biochemistry and Molecular Biology|date = 1999-02-01|issn = 0965-1748|pmid = 10196738|pages = 153–160|volume = 29|issue = 2|first1 = S. L.|last1 = Dobson|first2 = K.|last2 = Bourtzis|first3 = H. R.|last3 = Braig|first4 = B. F.|last4 = Jones|first5 = W.|last5 = Zhou|first6 = F.|last6 = Rousset|first7 = S. L.|last7 = O'Neill|doi=10.1016/s0965-1748(98)00119-2|doi-access = free}}

Although Wolbachia bacteria do not benefit their hosts in any way, they are maintained in the population because infected mothers pass them to their offspring through the ovum. Over time, bacterial presence in a population can lead to complete reproductive isolation of that population from uninfected populations. Wolbachia causes speciation through reproductive isolation. Some hosts evolve with a dependency on Wolbachia for reproductive functions, so that individuals without Wolbachia infections have lower reproductive fitness.

Wolbachia influences the gender determination of its hosts, making females more common than males. In populations affected by Wolbachia, females commonly compete for the right to mate with males. This is one of the ways in which Wolbachia infections can lead to speciation, because females evolve traits that allow them to better compete for males. In extreme cases, the feminizing effect of Wolbachia can cause the host species to lose the chromosome responsible for female gender. Wolbachia infections are capable of causing the extinction of hosts by making females much more common than males.

{{Reflist}}

• {{citation |last=Zicha |first=Ondřej |editor1=Ondřej Zicha |editor2=Jaroslav Hrb |editor3=Michal Maňas |display-editors=3 |editor4=Jiří Novák |title=Family Phytoseiidae. Taxon Profile |work=BioLib |year=2004 |url=https://www.biolib.cz/en/taxon/id19349/ |access-date=26 August 2015 |archive-url=https://web.archive.org/web/20140912025406/http://www.biolib.cz/en/taxon/id19349/ |archive-date=12 September 2014}}

• [http://entomology.ifas.ufl.edu/creatures/beneficial/Neoseiulus_californicus.htm Neoseiulus californicus, a predatory mite] on the UF / IFAS Featured Creatures Web site
• {{cite web |title=Phytoseiidae Species Listing |url=http://bug.tamu.edu/research/collection/hallan/Acari/Family/Phytoseiidae.txt |access-date=13 August 2015 |last=de Moraes |first=G.J. |work=Biology Catalog |editor=Hallan, Joel |archive-url=https://web.archive.org/web/20141212081418/http://bug.tamu.edu/research/collection/hallan/Acari/Family/Phytoseiidae.txt |archive-date=12 December 2014}}

{{Acari}}

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Category:Acari families

Category:Biological pest control agents