Allonychus

Superfamily Tetranychoidea

   Family Tetranychidae

      Subfamily Tetranychinae

        Tribe Tetranychini

          Genus Allonychus

Common names:

Probability of Encounter: Medium.

Quarantine importance: High.  Allonychus is a small genus similar to Panonychus with about 7 described species, mostly from South and Central America, but with two species known from China on bamboo.  A. braziliensis (McGregor) is found in Brazil, Cuba, Nicaraugua and Venezuela where it feeds on cassava, banana, avocado, mango, pear, cinnamon trees and other trees.

• Allonychus littoralis (McGregor) attacks avocado, cassava, cotton and some trees in Central and South America.

• Allonychus reisi Paschoal attacks cassava, cacao, figs and ornamentals such as azalea and rhododendron.

Diagnosis:

• With 2 pairs of paranal setae (h2-h3) and 2 pairs of anal setae.

• 10 pairs of opisthonotal setae.

• Empodium claw-like (mediodorsal spur) with a pair of minute dorsal 'hairs' and 4 pairs of proximoventral hairs of variable length, but some are longer than the claw and at less than right angles to the claw.

• 2 pairs of widely separated duplex setae on tarsus I.

Similar taxa.   Other Tetranychini have either 1 pair of paranal setae (e.g. Oligonychus, Tetranychus, Amphitetranychus) or have the empodium split distally, ending in a tuft of hairs, or divided into 2-3 claws or lack proximoventral hairs or have hairs longer than the claw (Allonychus).

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.

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.

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.