Bryobiinae

t

Taxonomy

Common names

brown wheat mite, legume mite, oxalis spider mite

Probability of encounter

high

Quarantine importance

High. The genus Petrobia contains more than 30 species often grouped into 3 subgenera of which several polyphagous species are important pests. 

• The brown wheat mite (also large brown wheat mite, garlic mite) P. (Petrobia) latens (Müller) attacks onion, galic, asparagus, strawberries, cucumber, spice crops, clover and other legumes, and a variety of grains.  P. latens is one of the few spider mites that is a proven vector, of barley yellow streak mosaic virus and probably carries the virus transovarially.
• P. (Mesotetranychus) tunisiae Manson feeds on grains and chrysanthemum in the Mediterranean region and Iran.
• The legume mite P. (Tetranychina) apicalis (Banks) attacks onions, peas, clover, vetch and other legumes in Europe and the USA.
• P. (Tetranychina) harti (Ewing) feeds on a variety of weeds, especially certain species of Oxalis, but also attacks citrus, tea, strawberry, apple, grape, sugarcane, clover and a variety of ornamentals and has been dispersed to most of the world.

Diagnosis

• With reddish brown cuticle, dark body contents, and very long legs I.
• Claws pad-like; empodium hooked and with more than 1 pair of tenent hairs.
• Prodorsum with 3 pairs of setae (ve, sci, sce), without prominent lobes over gnathosoma.
• Paranal setae (h2–3) in a ventral position.

Similar taxa

The true spider mites in the Tetranychinae do not have empodia with tenent hairs. The claws are pad-like in other tribes of Bryobiinae.

References

• Baker and Pritchard 1960Baker and Pritchard 1960:
  Baker EW, Pritchard AE. 1960. The tetranychoid mites of Africa. Hilgardia 29 (11): 455–574.
• Baker and Tuttle 1994Baker and Tuttle 1994:
  Baker EW, Tuttle DM. 1994. A guide to the spider mites (Tetranychidae) of the United States. Indira Publishing House, West Bloomfield, Michigan. 347 pp.
• Bolland et al. 1998Bolland et al. 1998:
  Bolland HR, Gutierrez J, Flechtmann CHW. 1998. World catalogue of the spider mite family (Acari: Tetranychidae). Brill, Leiden.
• Helle and Sabelis 1985Helle and Sabelis 1985:
  Helle W and Sabelis MW, eds. 1985. Spider mites: Their biology, natural enemies, and control. World Crop Pests, Vol. 1A. Elsevier, New York.
• Jeppson et al. 1975Jeppson et al. 1975:
  Jeppson LR, Keifer HH, Baker EW. 1975. Mites injurious to economic plants. University of California Press, Berkeley.
• Meyer 1974Meyer 1974:
  Meyer MKPS. 1974. A revision of the Tetranychidae of Africa (Acari) with a key to the genera of the world. Republic of South Africa, Department of Agricultural Technical Services, Entomology Memoir No. 36: 291 pp.
• Meyer 1987Meyer 1987:
  Meyer MKPS. 1987. African Tetranychidae (Acari: Prostigmata) - with reference to the world genera. Republic of South Africa, Department of Agriculture and Water Supply, Entomology Memoir No. 69: 175 pp.
• Robertson and Carroll 1988Robertson and Carroll 1988:
  Robertson NL, Carroll TW. 1988. Virus-like particles and a spider mite intimately associated with a new disease of barley. Science 240: 1188–1190.
• Smidansky and Carroll 1996Smidansky and Carroll 1996:
  Smidansky ED, Carroll TW. 1996. Factors influencing the outcome of barley yellow streak mosaic virus-brown wheat mite-barley interactions. Plant Disease 80 (2): 186–193.