Oligonychus

Superfamily Tetranychoidea

   Family Tetranychidae

      Subfamily Tetranychinae

        Tribe Tetranychini

          Genus Oligonychus

Common names: Banks grass mite, Spruce spider mite, Conifer spider mite, Avocado brown mite, Avocado red mite, Mango spider mite, Grasswebbing mite, Southern red mite, Persea mite, Sugarcane leaf mite, rice spider mite, corn spider mite, cotton spider mite

Probability of Encounter: Very high

Quarantine importance: Very High.  About 200 species of Oligonychus have been described including many polyphagous pests of high agricultural and forestry importance.  A variety of subgenera have been proposed, but the characters are often difficult to apply and many of the pest species are difficult to distinguish.  A few of the important pest species currently not known to be in the US include:

• Oligonychus afrasiaticus (McGregor) attacks maize, dates, ryegrass and other grasses.

• Oligonychus biharensis (Hirst) attacks apple, pear, grape, litchi, avocado, banana, guava, mango, and numerous ornamentals.

• Oligonychus gossypii (Zacher) attacks cotton, citrus, peach, papaya, beans, okra, peanut, and ornamentals.

• Oligonychus indicus (Hirst) attacks banana, soybean, maize, rice, sorghum, sugarcane, and other grasses.

• Oligonychus litchii Ehara attacks bamboo, maize, sugarcane, rice, other grasses and palm.

• Oligonychus mangiferous (Rahman & Sapra) attacks apple, pear, peach, grape, blackberry, litchi, avocado, banana, mango, pomegranate, sweet potato, cotton,and numerous ornamentals.

• Oligonychus mcgregori (Baker & Pritchard) attacks avocado, cassava, cotton, and ornamentals.

• Oligonychus shinkajii Ehara attacks maize, rice, sugarcane, bamboo and other grasses.

• Oligonychus thelytokous Gutierrez attacks avocado, litchi, mango, cassava, cotton, and ornamentals.

• Oligonychus zeae (McGregor) attacks banana, maize, sorghum, sugarcane, and other grasses.

Diagnosis:

• With 1 pair of paranal setae (h3); setae h2 terminal; seta h1 absent.

• With 10 pairs of opisthonotal setae (c1-3, d1-2, e1-2, f1-2, h2) and 3 pairs of prodorsal setae (ve, si, se).

• With 2 pairs of anal setae (ps1-2).

• Empodia claw-like, sickle-shaped and generally longer than the proximoventral hairs on female and legs II-IV on male; bifid on leg I of male.

• Duplex setae on tarsus I +/- adjacent.

 

Similar taxa.  Other Tetranychini have either 2 pairs of paranal setae (e.g. Allonychus, Panonychus) or  lack a claw (although a spur may be present ) and have empodia split into hair-like processes distally (e.g. Tetranychus, Amphitetranychus) or lack seta c2 (Xinella) or have empodial claws that are similar in length or shorter than the proximoventral hairs (Hellenychus).

References

 Baker EW & AE Pritchard.  1960.  The tetranychoid mites of Africa.  Hilgardia 29(11): 455-574.

 Baker EW & DM Tuttle.  1994.  A guide to the spider mites (Tetranychidae) of the United States.  Indira Pub. House, West Bloomfield, MI: 347 pp.

Beard JJ, Walter DE, & Allsopp P.  2003.  Spider Mites of Sugarcane in Australia: A Review of Grass-feeding Oligonychus Berlese (Acari: Prostigmata: Tetranychidae) with the description of four new species.  Australian Journal of Entomology 42: 51-78.

Bolland HR, J Gutierre  & CHW Flechtmann. 1998. World Catalogue of the Spider Mite Family (Acari: Tetranychidae). Brill: Leiden.

Helle W & MW Sabelis (eds.) 1985. Spider Mites, Their Biology, Natural Enemies, and Control, vol. 1A. Elsevier: New York.

Jeppson LR, HH Keifer & EW Baker. 1975. Mites Injurious to Economic Plants, University of California Press: Berkeley

Meyer, M.K.P. 1974.  A revision of the Tetranychidae of Africa (Acari) with a key to the genera of the world.  Dept. Agr. Tech. Serv. Mem. 36: 291 pp.

Meyer, M.K.P. Smith 1987.  African Tetranychidae (Acari: Prostigmata) - with reference to the world genera.  S. Afr. Dept. Agr. Water Supply, Entomol. Mem. No. 69: 175 pp.

Mignon A & CHW Flechtmann 2004.  First additions and corrections to the World Catalogue of the Spider Mite Family (Acari: Tetranychidae).  Intern. J. Acarol. 30: 143-152.

Ochoa R, H Aguilar & C Vargas 1994. Phytophagous Mites of Central America: An Illustrated Guide  CATIE, Turrialba, Costa Rica.

Tseng Y-H  1990.  A monograph of the mite family Tetranychidae (Acarina: Trombidiformes) from Taiwan.  Taiwan Museum Special Publication series 9. 224 pp.

Zhang Z-Q.  2003.  Mites of greenhouses: identification, biology and control.  CABI Publishing, Wallingford:  244 pp.