Is it a mite?

Nomenclature

Opilionida (Opiliones, Phalangida, including Cyphophthalmi)

Common names

harvestmen, opilionids, daddy-long-legs

Probability of encounter

high

Quarantine importance

No known importance.

Similarity to mites

Some groups very mite-like, especially in dorsal view where the body may appear unsegmented. However, at least the venter of the opisthosoma should be clearly segmented, even in immatures.

Morphology

Normal adult length: <15 mm
Body tagmata: prosoma, opisthosoma (but superficially appears as one body mass)
Eyes: 1 + 1 ocelli on median turret (or blind)
Antennae: absent
Mouthparts: 3-segmented chelicerae; leg-like or raptorial palps
Legs: 4 pairs; legs I or legs II antenniform
Distinguishing features: eye turret; repugnatorial glands; particulate feeding

Diversity

ca. 5,000 species

References

Edgar 1990Edgar 1990:
Edgar AL. 1990. Opiliones (Phalangida). pp. 529-581. In: Dindal DL. (Ed.) Soil biology guide. John Wiley & Sons, Brisbane.

Mite-like opilionid (Sironidae) (DEW)	Opilionid posterior showing segmentation (DEW)
Lateral view of opilionid (DEW)	3-segmented chelicera of opilionid (CB, DEW)
Venter of a sironid opilionid (CB)	Opilionid with leg-like palps (HCP, DEW)
Venter of an opilionid (CB)	Dorsum of opilionid with antenniform legs II (CB)
Siro acaroides (Oregon) (DEW)	Opilionid eyes on turret (DEW)
Troguloid opilionid (HCP)	Opilionid on wall (HCP)
Male guarding female during oviposition (HCP)	Siro nymph (immature) with visible segmentation (DEW)
3-segmented chelicerae in Siro