Flat Mites of the World

    a

  • ag setae: Aggenital setae - located ventrally on cuticle anterior to genital plate/flap. One pair present in the Family Tenuipalpidae. Denoted as ag or ag1.
  • anal plate: A pair of soft or sclerotised plates surrounding the anus. Each plate bears a 1-3 pairs of setae called pseudanal setae (ps setae).
  • antiaxial: The face of a paired appendage that is turned away from the plane of symmetry of the body. For example, an antiaxial solenidion would be located on the outer edge of leg II, when the leg is directed forwards and parallel with the body.
  • areolae: holes, cavities, depressions
  • areolate: having holes, cavities, depressions

    c

  • companion seta: Tactile seta found in close association with the solendion on tarsus I or II.
  • coxa: A segment of the leg - the closest segment to the body (it is actually fused to the body). Leg segments in order from body - coxa, trochanter, femur, genu, tibia, tarsus (bearing claws). Plural = coxae.

    d

  • deutonymph: An immature stage in the ontogenetic development of mites. The deutonymph is the penultimate developmental stage in the family Tenuipalpidae. There are four active stages after the egg in tenuipalp development - larva, protonymph, deutonymph and adult.

    e

  • empodium: A structure found between the claws on the tarsus of each leg segment. Plural = empodia.
  • eupathidion: A blunt-tipped sensory seta found distally on tarsus I-II and distally on the palp. Similar to a solenidion but without any annulation or stripes. Generally elongate, straight sided, reasonably short. Plural = eupathidia.

    f

  • femur: A segment of the leg - the third segment from the body. Leg segments in order from body - coxa, trochanter, femur, genu, tibia, tarsus (bearing claws). Plural = femora.

    g

  • g setae: Genital setae - present on the genital plate/flap. Usually two pairs present, inserted along the posterior margin of the plate. Denoted as g1 and g2.
  • genital plate: Area of cuticle between the ventral plate and anal plates/valves. The genital plate (sometimes called genital flap) covers the genital opening and ovipore. In most genera, the genital plate is unsclerotised but is distinctly delimited by folds in the cuticle that allow expansion during egg laying. An example of a sclerotised genital plate is the genus Brevipalpus. Usually bears 2 pairs of genital setae (g).
  • genital seta: Seta present on the genital plate/flap/valve. Usually two pairs present, inserted along the posterior margin of the plate. Denoted as g1 and g2.
  • genu: A segment of the leg - the fourth segment from the body. Leg segments in order from body - coxa, trochanter, femur, genu, tibia, tarsus (bearing claws). Plural = genua.

    o

  • opisthosoma: The dorsal opisthsoma includes the parts of the body posterior to the sejugal furrow (main dorsal fold in body between legs II and III). The ventral opisthosoma includes the parts of the body posterior to legs IV (including the ventral, genital and anal plates). See also the "Is it a flat mite?" page.

    p

  • palmate: Shaped like the leaf of a palm - broadly rounded and flat.
  • palp: The palp is one of a pair of appendages found on the infracapitulum (or gnathosoma) anteriorly on the body, between legs I-II. The palps have sensory setae and assist with feeding and tasting. The palps vary in segment number from 1-5.
  • paraxial: The face of a paired appendage that is turned towards the plane of symmetry of the body. For example, a paraxial solenidion would located on the inner edge of leg II, when the leg is directed forwards and parallel with the body.
  • pretarsus: The segment of the leg that is the most distal from the body. The pretarsus bears the empodium and the claws.
  • prodorsum: The dorsal area of the anterior body section. The prodorsum of flat mites bears 3 pairs of setae (v2, sc1, sc2) and 2 pairs of eyes (usually between sc1 and sc2). Often the anterior margin of the prodorsum varies in morphology - it can be produced into a flat or forked extension, smoothly rounded (or unmodified), deeply or weakly notched.
  • ps setae: Pseudanal setae - present on the anal plates/valves, located on the posterior venter, posterior to the genital region. One to three pairs are present in Family Tenuipalpidae. Denoted as ps1, ps2 etc.
  • pseudanal seta: Seta present on the anal plates/valves, located on the posterior venter, posterior to the genital region. Denoted as ps1, ps2 etc.

    r

  • reticulate: having a pattern of closed cells that form a network; similar to the cross-section of honeycomb
  • rugose: folds, wrinkles

    s

  • solenidion: A blunt-tipped sensory seta usually found on tarsus I-II. Usually distinctly annulate (i.e. with a series of thin bands visible along its length). Plural = solenidia.
  • spatulate: Shaped like a spatula. For example, a spatulate seta is narrow and paralell-sided at the base with a broad, flat rounded tip. Spatulate dorsal setae are characteristic of the genus Raoiella.
  • spermatheca: An internal structure loctated in females used for sperm storage. The spermatheca can be scerlotised and of characteristic morphology, e.g. the genus Brevipalpus.

    t

  • tarsus: The leg segment most distal from the body, bearing the pretarsus. Leg segments in order from body - coxa, trochanter, femur, genu, tibia, tarsus. Plural = tarsi.
  • tenent hairs: short "T-shaped" hairs found on the claws and/or empodium. The empodium tends to have a paired series of tenent hairs (usually 6-8). When the true claw is uncinate or claw-like, there is usually one tenent hair on the inner margin and one tenent hair on the outer margin. When claw is pad-like and resembles the empodium, there is a series of tenent hairs on both the inner and outer margins.
  • tibia: A segment of the leg - the second most distal leg segment. Leg segments in order from body - coxa, trochanter, femur, genu, tibia, tarsus (bearing claws). Plural = tibiae.

    v

  • ventral plate: Area of cuticle on the posterior venter, anterior to the genital region. Often distinctly delimited by a change in cuticle pattern; sometimes a distinctly sclerotised plate is present (e.g. Brevipalpus and Tenuipalpus). Usually bears a pair of aggential setae (ag).