Is it a mite?

t

Common names

pseudoscorpions

Probability of encounter

high

Quarantine importance

No known importance, but pseudoscorpions are predators capable of achieving high population densities and could be of conservation concern.

Similarity to mites

Small size, chelicerae, and mite-like build. Pseudoscorpions range from 0.5–10 mm in length, tend to be dorsoventrally flattened, and are cryptic in coloration. Their scorpion-like pedipalps may be short and massive or elongated into slender forceps. Opisthosomas are clearly segmented.

Morphology

Normal adult length: <10 mm
Body tagmata: prosoma and opisthosoma broadly fused
Eyes: 0–2 pairs of lateral ocelli
Antennae: absent
Mouthparts: 2-segmented, pincer-like chelicerae with elaborate structures (serrula and flagellum) on movable digit and usually 1 (rarely 3–4) submedian or subdistal hair; scorpion-like palps
Legs: 4 pairs; all legs used in walking
Distinguishing features: scorpion-like pedipalps, ventral embryo sac, serrula & flagellum on cheliceral digit; endocephalothracic silk system leading to pore on movable cheliceral digit

Diversity

>2,000 spp.

References

• Harvey 1985Harvey 1985:
  Harvey MS. 1985. Pseudoscorpionida. pp. 126–155. In: Main BY, Davies VT, McKay RJ, and Harvey MS. Zoological catalogue of Australia. Vol. 3: Arachnida. Australian Government Publishing Service, Canberra.
• Harvey 1991Harvey 1991:
  Harvey MS. 1991. Catalogue of the Pseudoscorpionida. Manchester University Press, Manchester.
• Harvey 1992aHarvey 1992a:
  Harvey MS. 1992a. The phylogeny and classification of the Pseudoscorpionida (Chelicerata: Arachnida). Invertebrate Taxonomy 6: 1373–435.
• Muchmore 1990Muchmore 1990:
  Muchmore WB. 1990. Pseudoscorpionida. pp. 503–527. In: Dindal DL, ed. Soil biology guide. John Wiley & Sons, Brisbane.
• Weygoldt 1969Weygoldt 1969:
  Weygoldt P. 1969. The biology of pseudoscorpions. Harvard University Press, Cambridge, Massachusetts.