Is it a mite?

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Common names

spiders

Probability of encounter

high

Quarantine importance

High for some taxa because of medical importance or potential general predator problems. Many large species are used in the pet trade and some may have small, endangered populations.

Similarity to mites

Spider-like build and lack of segmentation resemble mites, but mites do not have spider waists.

Morphology

Normal adult length: >5 mm
Body tagmata: prosoma (cephalothorax), opisthosoma (abdomen)
Eyes: 4 + 4 ocelli maximum
Antennae: absent
Mouthparts: fang-like chelicerae; feeler-like 5-segmented palps with distal claws (not present on palps of adult males); terminal segment of palps in males is swollen
Legs: 4 pairs (NB—some have long, leg-like spinnerets)
Distinguishing features: fangs, spinnerets, pedicel

Comments: Spiders all have two clearly defined body regions separated by a narrow waist (pedicel), fang-like mouthparts and abdominal spinnerets that produce silken threads. Male spiders have swollen palps.

Diversity

>38,000 spp.

References

• Platnick 2003Platnick 2003:
  Platnick NI. 2003 Jan. The World Spider Catalog. Version 3.5. American Museum of Natural History, New York.
• Tree of Life Web Project 2006Tree of Life Web Project 2006:
  Tree of Life Web Project. 2006. Araneae. Spiders. Version 07 December 2006 (temporary). The Tree of Life Web Project, http://tolweb.org/