Shortcut to Major Taxa of Quarantine Concern

Almost any kind of mite could be found in a quarantine intercept, but only some groups contain species of particular interest.  The major groups of mites of quarantine concern are listed below.

If you already know which of these groups your mite belongs to, you can choose that group and eliminate the rest.  If you then use the 'Prune Redundants' button, Lucid will remove those characters no longer relevant to identifying the specimen.

Order Ixodida - ticks

Ticks are easily distinguished from other mites by their distinctive subcapitulum which is covered by retrorse teeth that ticks use to anchor their mouthparts in the skin when feeding. The capitulum is visible from above in hard ticks, but usually more or less covered by the body is soft ticks.  The distal palp segment is usually well developed in soft ticks (Argasidae), but reduced and recessed in most hard ticks (Ixodidae).  The subcapitilum is anarthric (without a labiogenial suture) and often has more than 4 pairs of setae.  The chelicerae are highly modified for cutting skin and appear 2-segmented.

Order Mesostigmata - phytoseiids, laelapids, macrochelids and their relatives

Mesostigmatans could be confused with ticks since they have a tick-like capitulum completely encircled by a band of cuticle (the basis capitulum), but they lack the retrorse teeth on the subcapitulum, and usually have a median gutter with rows of denticles, a tritosternum, and a pair of corniculi.  Additionally, the lateral stigmatal opening is usually associated with a microtuberculate groove called the peritreme.  Each of these particular structures is unique to the Mesostigmata.

Suborder Oribatida - oribatid mites (including Astigmatina)

The Suborder Oribatida now includes the traditional oribatid mites and the well known Cohort (and former suborder) Astigmatina.  In this more general sense, the Oribatida includes all of the members of the Order Sarcoptiformes that are likely to be of quarantine concern, leaving out only the early derivative lineages of the Suborder Endeostigmata.  Characterizing such a large assemblage of mites is difficult, but their capitulum is easily distinguished from that of the Mesostigmata and Ixodida by the lack of the basis capitulum, tritosternum, corniculi, median gutter, and retrorse teeth.  The bases of the chelicerae are always exposed, but in many oribatid mites the capitulum is folded away in a camerostome.  Oribatids also usually have well developed rutella and, except in the Astigmatina, one pair of prodorsal trichobothria.  Most traditional oribatids and Astigmatina also have a pair of opisthosomal glands, and most traditional oribatids have a well developed ovipositor.

Cohort Astigmatina

The well known Suborder Astigmata (Acaridida) has been reduced to a cohort in Suborder Oribatida in the current classification in recognition of their close relationship to traditional oribatid mites.  Most Astigmatina resemble the immature stages of oribatid mites in having monodactyl claws, but lack prodorsal trichobothria and have only 2-segmented palps.  The heteromorphic deutonymph of many Astigmatina are distinctive dispersal stages called hypopi.  These can always be distinguished from other mites by their regressive capitulum and usually by possessing a ventral sucker plate.

Suborder Prostigmata

Because of all of the important acarine pests of plants belong to the Prostigmata, many of the mites encountered in quarantine will belong to this very large suborder.  Spider mites and their relatives (Tetranychoidea) are easily identified because they have highly modified chelicerae that are produced into whip-like structures that may be withdrawn into the body.  Most prostigmatans have anterior stigmatal openings, but these are often very difficult to see.  They sometimes have tenent hairs on their feet, are often soft-bodied, and are sometimes highly colorful.  They never have tritosterna, rutella or corniculi, but some have trichobothria and genital papillae.