Exotic mite families

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Taxonomy

updated 2025

Common names

clover mites

Probability of encounter

high

Quarantine importance

High. The Bryobiinae contains a number of important pests of grains, fruit trees, and some other crops.

Diagnosis

• Empodiumempodium:
  (pl. empodia) an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
  with tenent hairs
• Prodorsumprodorsum:
  the dorsal surface of the propodosoma.
  with 4 pairs of setae (vi, ve, sci, sce)
• Adult female with 3 pairs of anal setae (males with 5 pairs of ano-genital setae)
• Cheliceralcheliceral:
  of or pertaining to the chelicera.
  bases adnate, fused mesally into a stylophorestylophore:
  chelicerae formed of fused cheliceral bases bearing stylet-like movable digits as in Raphignathae (Prostigmata), e.g., the plant parasitic spider mites and their relatives (Tetranychoidea).  In predatory and parasitic Cheyletoidea and parasitic Myobiidae, the stylophore and subcapitulum are fused into a gnathosomal capsule.
  (sometimes withdrawn into the bodybody:
  the idiosoma of mites.
  ); chelicerae with fixed digitfixed digit:
  the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
  reduced and movable digit whiplike.
• Peritremes typically chamberedchambered:
  a structure with discrete compartments, e.g., the peritremes of some ologamasids (Mesostigmata) and prostigmatans.
  structures on the dorso-lateral surface of the prodorsumprodorsum:
  the dorsal surface of the propodosoma.
  ; naso absent; prodorsal trichobothriatrichobothrium:
  (pl. trichobothria) (= bothridial sensillum) an often elaborately modified seta set in a cup-like base; forms include filiform, ciliate, pectinate or variously thickened or clubbed (bat-like to globose or capitate).
  absent; 2 pairs of eye lenses usually present. Palps 5 segmented; with thumbclaw process (claw-like seta on the palp tibiatibia:
  (pl. tibiae) the leg segment between the genu and the tarsus.
  and a thumb- or button-like subterminal palp tarsustarsus:
  (pl. tarsi) the subdistal leg segment between the tibia and the pretarsus (apotele).
  ). Leg tarsitarsus:
  (pl. tarsi) the subdistal leg segment between the tibia and the pretarsus (apotele).
  usually with tenent hairs on claws or empodiumempodium:
  (pl. empodia) an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
  . Genital papillaegenital papillae:
   1-3 pairs of extrusible finger-like to button-like projections, usually retracted into in the genital vestibule of acariform mites; sometimes formed as sessile disks around the genital opening; thought to be osmoregulatory structures; modified or multiplied and dispersed over the body in many freshwater mites.  Genital papillae are absent in the larva, but may be added ontogenetically: protonymphs have one pair, deutonymphs two pairs, and tritonymphs (and adults) three pairs.  The tritonymphal pair of papillae is often lost.  The serially homologous Claparède's organ is usually present in the larvae (and prelarvae) of mites exhibiting genital papillae in nymphs and adults (Oudeman's Rule).
  absent; males with an intromittent aedeagus.

Open Bryobiinae key

Similar taxa

The true spider mites in the Tetranychinae do not have empodiaempodium:
(pl. empodia) an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
with tenent hairs.

Ecology and distribution

Bryobiinae are often found on twigs or the undersides of leaves. They are not able to produce silksilk:
fine threads spun by acariform mites to form a molting chamber (cocoon), protect or attach eggs, or a loosely defined to finely woven web.
and do not have a spinneretspinneret:
a structure that produces silken fibers.  In spider mites, the spinneret is in the form of a short, blunt seta-like structure on the palp tarsus.
on their palp tarsustarsus:
(pl. tarsi) the subdistal leg segment between the tibia and the pretarsus (apotele).
.

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, and Baker EW. 1975. Mites injurious to economic plants. University of California Press, Berkeley.
• Migeon and Flechtmann 2004Migeon and Flechtmann 2004:
  Migeon A and Flechtmann CHW. 2004. First additions and corrections to the World Catalogue of the Spider Mite Family (Acari: Tetranychidae). International Journal of Acarology 30 (2): 143-152.
• Ochoa et al. 1994Ochoa et al. 1994:
  Ochoa R, Aguilar H, and Vargas C. 1994. Phytophagous mites of Central America: An illustrated guide. CATIE, Turrialba, Costa Rica.
• Tseng 1990Tseng 1990:
  Tseng Y-H. 1990. A monograph of the mite family Tetranychidae (Acarina: Trombidiformes) from Taiwan. Taiwan Museum Special Publication Series 9. 224 pp.
• Zhang 2003Zhang 2003:
  Zhang Z-Q. 2003. Mites of greenhouses: Identification, biology and control. CABI Publishing, Wallingford. 244 pp.