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Spider mites are members of the family Tetranychidae, which includes about 1,200 species.[1] They are part of the subclass Acari (mites). Spider mites generally live on the undersides of leaves of plants, where they may spin protective silk webs, and can cause damage by puncturing the plant cells to feed.[2] Spider mites are known to feed on several hundred species of plants.

Spider mites
Temporal range: Palaeogene–present
Tetranychus urticae
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Trombidiformes
Superfamily: Tetranychoidea
Family: Tetranychidae
Donnadieu, 1875
Subfamilies & tribes

Bryobinae Berlese

  • Bryobini Reck
  • Hystrichonychini Pritchard & Baker
  • Petrobiini Reck

Tetranychinae Berlese

  • Tenuipalpoidini Pritchard & Baker
  • Tetranychini Reck

Description

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Spider mites are less than 1 mm (0.04 in) in size and vary in color. They lay small, spherical, initially transparent eggs and many species spin silk webbing to help protect the colony from predators; they get the "spider" part of their common name from this webbing.[2]

Life cycle

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Spider mites on a lemon plant

Hot, dry conditions are often associated with population build-up of spider mites. Under optimal conditions (approximately 27 °C), the two-spotted spider mite can hatch in as little as 3 days, and become sexually mature in as little as 5 days. One female can lay up to 20 eggs per day and can live for 2 to 4 weeks, laying hundreds of eggs. This accelerated reproductive rate allows spider mite populations to adapt quickly to resist pesticides, so chemical control methods can become somewhat ineffectual when the same pesticide is used over a prolonged period.[3]

Spider mites, like hymenopterans and some scale insects, are haplodiploid and therefore arrhenotochous: females are diploid and males are haploid.[4] When mated, females avoid the fecundation of some eggs to produce males. Fertilized eggs produce diploid females. Unmated, unfertilized females still lay eggs that originate exclusively haploid males.

To spread to new locations, they make use of ballooning for aerial dispersal.[5]

Video of multiple spider mites walking on a leaf

Genera

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The best known member of the group is Tetranychus urticae, which has a cosmopolitan distribution,[6] and attacks a wide range of plants, including peppers, tomatoes, potatoes, beans, corn, cannabis, and strawberries.[3] Other species which can be important pests of commercial plants include Panonychus ulmi (fruit tree red spider mite) and Panonychus citri (citrus red mite).

The family is divided into these subfamilies, tribes and genera:[7]

Bryobinae Berlese
  • Bryobini Reck
  • Hystrichonychini Pritchard & Baker
  • Petrobiini Reck
Tetranychinae Berlese
  • Eurytetranychini Reck
  • Tenuipalpoidini Pritchard & Baker
  • Tetranychini Reck

Countermeasures

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Predatory mites

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Predatory mites of the family Phytoseiidae, including Phytoseiulus persimilis, eat adult mites, their eggs, and all developmental stages between.[3] Predatory mites can consume as many as 5 adult spider mites per day, or 20 eggs per day.[3]

Harpin Alpha Beta

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In some cases, the application of Harpin Alpha Beta protein may help in the treatment and prevention of infestation by stimulating the plant's natural defenses, restoring sap sugar levels and encouraging replacement of damaged tissues.[8] This affects the spider mites' ability to down-regulate the immune response of a plant.[9]

Acaricides

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Acaricides are applied to crops to control spider mites. They can be either systemic or non-systemic in nature and can be persistent by providing residual activity for over a month. Drawbacks include high potential for development of resurgence and resistance in mite populations, as has been observed in previous generations of miticides, and toxicity of some miticides towards fish. Thus proper selection, precautions and application are required to minimize risks.[10][11][12]

Environmental conditions

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Temporarily modifying environmental conditions has proven an effective method for insect pest control including spider mites. Generally dramatically decreased oxygen and increased carbon dioxide concentrations at elevated temperatures can lead to mortality at all developmental stages. However mild CO2 enrichment has been shown to in fact increase mite reproduction.[13] One study determined a concentration of 0.4% O2 and 20% CO2 gave a LT99 (time to 99% mortality) of 113h at 20 °C and 15.5h at 40 °C.[14] Another study reported 100% mortality of various stages of the two spotted spidermite using 60% CO2 and 20% O2 at 30 °C for 16h.[15][clarification needed] Advantages would include decreased ability for resistance development compared to miticides and potential ease of application while drawbacks might include sensitivity of the plant to the conditions, feasibility of application, and human safety.

See also

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References

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  1. ^ H. R. Bolland; Jean Gutierrez & Carlos H. W. Flechtmann (1997). "Introduction". World Catalogue of the Spider Mite Family (Acari: Tetranychidae). Brill Publishers. pp. 1–3. ISBN 978-90-04-11087-8.
  2. ^ a b Yutaka Saito (2009). "Plant mites". Plant Mites and Sociality: Diversity and Evolution. Springer. pp. 5–38. doi:10.1007/978-4-431-99456-5_2. ISBN 978-4-431-99455-8.
  3. ^ a b c d Thomas R. Fasulo & H. A. Denmark (December 2009). "Twospotted spider mite". Featured Creatures. University of Florida / Institute of Food and Agricultural Sciences. Retrieved May 20, 2011.
  4. ^ Graham Bell (1982). "Parthenogenesis and vegetative reproduction in multicellular animals". The Masterpiece of Nature: the Evolution and Genetics of Sexuality. Croom Helm applied biology series. Cambridge University Press. pp. 160–331. ISBN 978-0-85664-753-6.
  5. ^ Simonneau, Manon; Courtial, Cyril; Pétillon, Julien (2016). "Phenological and meteorological determinants of spider ballooning in an agricultural landscape" (PDF). Comptes Rendus Biologies. 339 (9–10): 408–416. doi:10.1016/j.crvi.2016.06.007. PMID 27527898.
  6. ^ D. A. Raworth; D. R. Gillespie; M. Roy & H. M. A. Thistlewood (2002). "Tetranychus urticae Koch, twospotted spider mite (Acari: Tetranychidae)". In Peter G. Mason & John Theodore Huber (eds.). Biological Control Programmes in Canada, 1981–2000. CAB International. pp. 259–265. ISBN 978-0-85199-527-4.
  7. ^ H. R. Bolland; Jean Gutierrez & Carlos H. W. Flechtmann (1997). "Key to the genera of the world". World Catalogue of the Spider Mite Family (Acari: Tetranychidae). Brill Publishers. pp. 5–11. ISBN 978-90-04-11087-8.
  8. ^ "HALO Foliar Plant Feed - Studies". www.halo-harpin.com. Retrieved 9 May 2017.
  9. ^ "The effect of harpin protein on plant growth parameters, leaf chlorophyll, leaf colour and percentage rotten fruit of pepper plants inoculated with Botrytis cinerea (PDF Download Available)". ResearchGate. June 2006. Retrieved 9 May 2017.
  10. ^ Uesugi, R.; Goka, K.; Osakabe, M. H. (2002-12-01). "Genetic Basis of Resistances to Chlorfenapyr and Etoxazole in the Two-Spotted Spider Mite (Acari: Tetranychidae)". Journal of Economic Entomology. 95 (6): 1267–1274. doi:10.1603/0022-0493-95.6.1267. ISSN 0022-0493. PMID 12539841. S2CID 24716020.
  11. ^ "Table 4. Toxicity to fish of commonly used insecticides, miticides, and nematicides". Virginia Tech. Retrieved 2016-03-22.
  12. ^ "All Miticides Are Not Created Equal". Home, Yard & Garden Pest Newsletter. University of Illinois. Retrieved 2016-03-22.
  13. ^ Heagle, A. S.; Burns, J. C.; Fisher, D. S.; Miller, J. E. (1 August 2002). "Effects of Carbon Dioxide Enrichment on Leaf Chemistry and Reproduction by Twospotted Spider Mites (Acari: Tetranychidae) on White Clover". Environmental Entomology. 31 (4): 594–601. doi:10.1603/0046-225X-31.4.594.
  14. ^ Whiting, D. C.; Van Den Heuvel, J. (1 April 1995). "Oxygen, Carbon Dioxide, and Temperature Effects on Mortality Responses of Diapausing Tetranychus urticae (Acari: Tetranychidae)". Journal of Economic Entomology. 88 (2): 331–336. doi:10.1093/jee/88.2.331.
  15. ^ Oyamada, Koichi; Murai, Tamotsu (2013). "Effect of Fumigation of High Concentration Carbon Dioxide on Two Spotted Spider Mite, Tetranychus urticae Koch (Acari: Tetranychidae) and Strawberry Runner Plant". Japanese Journal of Applied Entomology and Zoology. 57 (4): 249–256. doi:10.1303/jjaez.2013.249.
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