Glossary of Acarine Terms
A work in progress © David Evans Walter 2005
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
abaxial - away from the axis of the body (midline), e.g. the outer or lateral face of a chelicera (also antiaxial).
abdomen - loosely used term usually referring to the opisthosoma or hysterosoma in mites.
abjugal plane (furrow) - a mostly theoretical division between the podosoma and gnathosoma.
acanthoides - eupathidia
acarodomatium (pl. acarodomatia) - plant morphogenetic structures that serve as refugia for mites; hideaways at the juncture of two veins on the ventral surface of the leaves of certain plants that are often inhabited by predatory or fungivorous mites; also domatia.
accessory seta - in the Eriophyoidea, opisthosomal seta h1.
acetabulum - a concave cavity in the body wall where a leg or other structure is inserted; in brachypyline oribatids they may be cavities where the trochanter articulates with the coxae (which are fused to the body wall) and may contain tracheal stigmata; the genital opening and papillae of acariform mites are contained within an acetabulum; also, the concave portion of a ball and socket joint.
aciniform - resembling a cluster of grapes.
acrotarsus (= apicotarsus) - distal subdivision of the tarsus, usually of tarsus I (NB - not to be confused with the ambulacral stalk or pretarsus).
Actinedida - term used for the Prostigmata in Krantz 1978.
actiniform - with radiating rays that resemble a sea anemone; actiniform cheliceral appendage of some Uropodoidea
actinopilin - optically active component of the core of birefringent setae in acariform mites that is resistant to maceration in lactic acid. The actinopilin core is surrounded by an isotropic layer that forms the outer surface. Actinopilin may occur in true setae (typical mechanoreceptors and trichobothria) and the eupathidia and famuli which have a protoplasmic core. Solenidia do not have actinopilin. (Also actinochitin).
Actinotrichida - the Acariformes; those mites having setae containing actinopilin. (see Anactinotrichida).
acuminate - coming to a point.
ad 1-3 - designations for the setae on the anterior dorsal surface of a leg or palp segment in the Mesostigmata (see Evans leg chaetotactic system). Also, the designations for the setae of the adanal segment in Acariformes (see Grandjean system). [Back to Top]
AD - adanal segment in acariform mites; added on the deutonymph, see anamorphosis. (See Grandjean system.)
adanal plate (or region) - sclerites or sclerotized fields laterad the anal region; usually used in oribatid mite taxonomy and bearing adanal setae.
adanal setae - setae on the adanal plate or region in acariform mites; paranal setae in Mesostigmata
adaxial - towards the axis of the body (midline), e.g. the inner face of a chelicera (also paraxial).
adgenital sclerite (plate; inguinal pore plate) - in gamasine Mesostigmata, a pair of small sclerites in the region of the posterior corners of the genital shield and parapodals IV that bears the inguinal glands gv2.
adjacent - in reference to structures next to one another, contiguous; as opposed to separated.
adoral - referring to setae distal on the subcapitulum of acariform mites (designations ao1, ao2)
aedeagus - a male intromittent organ, especially when sclerotized (e.g. in Tetranycoidea, Raphignathoidea); a penis is a flexible, membranous intromittent organ, although 'penis' is often used for aedeagi (e.g. in Astigmata).
aff. (also affin.) - affinis (L. related to, adjacent to), used for uncertain species designations (e.g. Cosmolaelaps aff. vacua (Michael)), meaning 'similar to', and implying that the specimen referred to may represent a new species (see nr., sp. nr., and cf.).
ag - a designation used for aggenital or pregenital setae in the Acariformes, e.g. ag1-3.
aggenital (also adgenital) plate (or region) - sclerites or sclerotized fields on either side of the genital opening.
al 1-2 - designations for the setae on the anterior lateral surface of a leg or palp segment in the Mesostigmata. (See Evans leg chaetotactic system.)
alternating calyptostasy - the alternation of calyptostatic and elattostatic developmental stages as seen in Parasitengona, Pterygosomatidae, and some other Prostigmata.
alveolus - a setal socket (also a single depression in alveolate ornamentation). [Back to Top]
ambulacrum - the claws and empodium of the apotele or pretarsus (technically including the ambulacral stalk [confusingly sometimes also called 'pretarsus'] and apotele [empodium and claws]).
AN - anal segment in acariform mites; added on the protonymph, see anamorphosis. (See Grandjean system.)
Anactinotrichida - the Parasitiformes; those mites not having setae containing actinopilin. (see Actinotrichida).
anal lobe - in the Eriophyoidea, the most posterior region of the body (segment PS) containing the anal opening and usually acting as an adhesive disk to anchor the body during feeding.
anal pedicel - a stalk produced from a cement-like secretion from the anal opening of deutonymphal sejines and uropodines which is used to attach to a phoretic host.
Anals - the pseudanal setae ps1-3 in the Pritchard & Baker System.
anal seta - any seta on an anal valve or ascribed to the anal region; pseudanal setae ps1-3 in spider mites; true anal setae may be present in acariform mites that add segment AN.
anal shield - in Mesostigmata, a ventral shield bearing the anal opening and circumanal setae (po, pa), but without any ventral setae or pores (lyrifissures) [see ventrianal shield].
anal sucker plate - the complex attachment organ on the posterior venter of astigmatan hypopi.
anal suckers - a pair of modified setae near the anal opening of male Astigmatina that act as suckers for holding onto females during precopula and mating.
anal valve - a shield protecting the anal opening.
anamorphosis - the addition of body segments (and their structures) during ontogeny; in Acariformes, additions occur behind the anal opening (pseudanal segment in the larva): anal (AN) in the protonymph, adanal (AD) in the deutonymph, peranal (PA) in the tritonymph. [Back to Top]
anarthric - an unjointed subcapitulum without a labiogenal suture or scissure.
anemorhria - dispersal by air, as in spider mites and eriophyoid mites.
annulate - with a ring-like ornamentation, especially the series of annulations characteristic of the integument of some eriophyoid and endeostigmatic mites.
annulus (pl. annuli) - a ring like structure or ornamentation.
anogenital region - the ventral region encompassing the genital, aggenital, anal and adanal sclerites in oribatid mites.
antenniform - having the form of antennae, typically used for long slender legs I that often lack the apotele, or for palps that resemble antennae (e.g. Bdellidae).
anteriad - to the front (do not use with the preposition 'to' since this is part of the meaning of the word), e.g. 'setae ro are usually inserted anteriad setae le'.
anterior - the front part of the body or towards that region in comparison, e.g. 'anterior to'.
anterior dorsal seta - setae (see ad 1-3) on the anterior dorsal surface of a leg or palp segment in the Mesostigmata.
anterior eye - the more anterior of a pair of lateral ocelli, usually having the more eye-like lens.
anterior hypostomal (also hypostomatic) setae - the most anterior (h1) of the three pairs of hypostomatic setae in the Mesostigmata; present in the larva.
anterior para-anals - setae h3 in the Pritchard & Baker System
anterior shield seta - in the Eriophyoidea, the unpaired, median internal vertical seta vi ('single anterior shield seta') or the paired external vertical setae ve.
anterolaterals (a) - a pair of ventral setae between the subunguinal seta and the primiventrals on the tarsi of acariform mites (see whorl).
anterolateral seta - either of the setae (al 1-2) on the anterior lateral surface of a leg or palp segment in the Mesostigmata.
anteromedial seta - in Mesostigmata (e.g. Veigaiidae), palpgenual seta al1.
anteroventral seta - a seta (av 1-3) on the anterior ventral surface of a leg or palp segment in the Mesostigmata.
antiaxial - away from the axis of the body (midline), e.g. the outer or lateral face of a chelicera (also abaxial).
antiaxial lyrifissure - the lyrifissure on the outer face of the chelicera in Mesostigmata.
apical - at the tip of a structure. [Back to Top]
apicotarsus (= acrotarsus) - distal subdivision of the tarsus, usually of tarsus I.
apodeme - sclerotized invagination of the cuticle, often at the margin of a plate, that serves as attachment site for muscles.
apoderm - a cuticle formed during development that lacks limbs and setae (see calyptostase).
apophysis - an internal projection from the body wall, often a site of muscle attachment.
apotele - (Gr apotelein = to complete) - the terminus of an appendage; the most distal leg segment, often consisting of an empodium and a pair of claws. The apotele of a leg is usually treated as equivalent to the pretarsus or some part thereof (e.g. the claws and empodium), but the palptarsal apotele in Mesostigmata is a tined structure originating at the base of the palptarsus and thought to be a remnant of the claws. The chelicerae are also an appendage and terminate in the movable digit.
approximate - close together, near, adjacent.
arborescent - branched like a tree, tree-like, dendritic.
area porosae - usually round to oval aggregations of pore-like areas of the cuticle; usually referring to the octotaxic system of the Oribatida.
area punctata - usually grape-like (aciniform) clusters of punctae on the sternal shields of some Mesostigmata.
armored mite - any mite encased in armor, but especially members of the Oribatida and Uropodoidea.
arolium (pl. arolia) - a membranous pouch-like structure; e.g. the cavity in which the empodia are situated in Neilstigmaeus (Prostigmata: Stigmaeidae).
arthrodial brush - a brush like extension of the arthrodial membrane at the articulation of the movable and fixed digits in some Mesostigmata. Not to be confused with cheliceral excrescences that are produced from openings in the movable digit.
arthrodial corona (coronet) - a crown-like array of fine processes from the arthrodial membrane at the juncture of the fixed and movable digits in Mesostigmata.
arthrodial membrane - the soft cuticle at any articulation, but often specifically used for the juncture of the movable and fixed digits in Mesostigmata. The membrane may have a crown-like corona of fine processes or be extended into a brush-like structure. [Back to Top]
articulation - a region of differentiated cuticle joining two parts of an exoskeleton; a joint, scissure or furrow.
aspis - a sclerotized shield over the aspidosoma.
aspidosoma - the anterior dorsal region of the prosoma in acariform mites.
astegasime - having the chelicerae exposed dorsally: the rostral tectum is reduced or absent (see stegasime), as in many Prostigmata, Astigmata and some early derivative oribatids.
Astigmata - an obsolescent name used for the suborder of acariform mites having no apparent stigmatal openings. Astigmatans are usually associated with (and often parasitic on) larger animals including insects and vertebrates; many species are pests in stored products. Astigmata appears to have been derived within the Oribatida and is no longer given subordinal rank (see Astigmatina).
astigmatan - a member of the Astigmata; characteristic of or belonging to the Astigmata.
astigmatic - adjectival form of Astigmata.
Astigmatina - the cohort of Sarcoptiformes containing astigmatic mites; a group of oribatid mites without bothridial sensillae [sic], usually soft-bodied, and often producing a heteromorphic deutonymph (hypopus). (See Astigmata.)
astigmatid - incorrectly formed, but commonly used, adjectival form of Astigmata; an astigmatan.
atelebasic rutellum - large rutellum with the apex expanded, toothed, and with a paraxial lobe as in Desmonomata and some Brachypylina.
atrium - in phytoseioid Mesostigmata (Phytoseiidae, Blattisociidae, Otopheidomenidae), a valve-like region of the sperm access system which the major duct to the calyx and gives rise to the minor duct.
auxilary stylets (= inner infracapitular stylets) - a pair of stylets of uncertain origin in the bundle of 7-9 stylets in the Eriophyoidea.
av 1-3 - designations for the setae on the anterior ventral surface of a leg or palp segment in the Mesostigmata. (See Evans leg chaetotactic system.) [Back to Top]
basad - towards the base of a structure.
basal - towards the base of a structure; on a limb, towards the insertion on the body.
basal article - the most basal of the maximum of three segments of the chelicera; usually absent or obscure in Acariformes.
base - the usually columnar basal part of the tritosternum; sometimes expanded and rectangular or otherwise modified; the most basal part of any structure.
basilar piece - the median internal structure with which the claws articulate in the ambulacrum of Mesostigmata.
basilar sclerite - a sclerotized structure to which the cheliceral muscle attach and which articulates with the movable cheliceral digit in some Prostigmata (analogous to the sclerotized node in some Uropodina).
basifemur - a basal subdivision of the femur of the leg or palp.
basitarsus - a basal subdivision of the tarsus.
basis capitulum (also basis gnathosomatica) - the sclerotized ring around the base of the capitulum in mesostigmatans and ticks; derived from dorsal and ventral extensions of the palpcoxae. The basis capitulum bears the corniculi, internal malae, and hypostomal and palpcoxal setae ventrally and the gnathotectum (epistome) dorsally.
bayonet-like - resembling a long, sharp blade used for stabbing, as in some corniculi; sword-like.
bdellid - a snout mite in the family Bdellidae (Prostigmata) (from the Greek for leech) usually with elbowed palps and often bright red in color (rarely purple).
bicuspid - having two points or cusps, e.g. the gnathotectum of some Mesostigmata.
biflagellate - with two whip-like processes as in many mesostigmatan tritosterna.
bifurcate - split into two distally or with two projections. [Back to Top]
bipectinate - a seta or other process having comb-like teeth on two sides (see pectinate).
biserrate - with saw-like teeth on two sides (see serrate).
bivalved - with two longitudinal plates or valve-like coverings.
blister mite - a species of Eriophyoidea that produces blister-like galls on the leaves of plants, typically flattened, subcircular swellings of the leaf surface over a cavity in the leaf lamina (parenchyma).
body divisions - apparent subdivisions of the idiosoma in Acariformes.
bothridial sensillum (= trichobothrium) - an often elaborately modified seta set in a cup-like base; forms include filiform, ciliate, pectinate or variously thickened or clubbed (bat-like to globose to capitate).
bothridial seta - prodorsal seta bo (also sci or s1) in Acariformes; the bothridial sensillum or trichome.
bothridium - the cup-like base of a bothridial sensillum.
box mites - oribatid mites that exhibit ptychoidy, the ability to withdraw their limbs and close-up like a box.
brachypyline - having separate genital and anal plates surrounded by a large ventral plate (composed of aggenital and adanal elements); usage usually restricted to traditional oribatid mites (see macropyline).
brachytracheae - thick, elongated and porose tube-like invaginations in the cuticle of some oribatid mites.
broad mite (also tea mite) - Polyphagotarsonemus latus (Banks) a plant-parasitic tarsonemid mite.
bruststiele - see Claparède's organ, urstigma
bud mite - a species of Eriophyoidea that galls buds on plants, e.g. the Filbert Big Bud Mites Phytoptus avellanae Nalepa (PHYTOPTIDAE) and Cecidophyopsis vermiformis (Nalepa) (ERIOPHYIDAE).
bursa copulatrix - a secondary sperm system opening terminally in some Prostigmata and Astigmatina.
c - a designation used for setae on segment C in the Acariformes, e.g. c1-3. (See Grandjean system.)
C - a designation used for the anterior region (apparent segment) of the hysterosoma in Acariformes. (See Grandjean system.)
californicus - the phytoseiid mite Neoseiulus (also Amblyseius) californicus (McGregor), a generalist predator used in a variety of cropping systems. Also the California mite.
calyptostase (adj. calyptostatic) - one of the abnormal stases recognized by Grandjean where neither mouthparts nor legs are functional, e.g. most prelarvae; the protonymph and tritonymph in Parasitengona. A calyptostase may have no sign of limbs or setae so that only a cuticle remains (apoderm). In such cases (e.g. the prelarvae of most oribatids), the calyptostase is retained within the egg shell or the cuticle of the previous instar and is also an endostase. In contrast the prelarvae of many Endeostigmata and some Prostigmata (e.g. Bdellidae) pop out of the egg and are considered ectostases (also see elattostase).
calyx (= cervix)- in phytoseioid Mesostigmata (Phytoseiidae, Blattisociidae, Otopheidomenidae, Podocinidae), a collar-like structure of the sperm access system which surrounds the base of the vesicle.
camerostome - a recess under the rostral tectum that allows retraction of the chelicerae and palps of oribatid mites and that is sealed by the subcapitulum when retracted; a deep recess containing the gnathosoma in Uropodina.
capitate - with a terminal knob or head-like swelling; clavate; globose.
capitular capsule (also gnathosomal capsule) - the fused chelicerae and subcapitulum.
capitulum (pl. capitula) (= gnathosoma) - the anteriormost part of a mite, composed of the cheliceral and pedipalpal segments and separated from the body (idiosoma) by a ring of soft cuticle. Sometimes called the rostrum, infracapitulum, or hypostome.
capsule - as in gnathosomal capsule, the fused chelicerae and subcapitulum characteristic of Tarsonemina and some other Prostigmata (e.g. Cheyletoidea, Myobioidea) (also tegmen, rostral shield).
carapace - the shield covering the dorsal prosoma of arachnids; in some European literature, the mesostigmatan podonotal shield. [Back to Top]
carina - a longitudinal ridge.
caudal bend - the posteroventral curvature of the opisthosoma that results in the anal opening being ventral in most mites. Opilioacarida have a terminal anus (the presumed primitive condition) and others have secondarily terminal or even dorsal anal openings.
caudally - in reference to the rear end.
caudal seta - in the Eriophyoidea, opisthosomal seta h2, often the longest seta on the mite and curled or whip-like.
cephalothoracic shield - the prodorsal shield, especially in the Eriophyoidea.
cepheid - a member of the brachypyline oribatid family Cepheidae, the nymphs of which often carry elaborate scalps.
cement layer - the outermost layer of the cerotegument; often produced in an ornamental pattern.
cerotegument - the outer layers of the epicuticle, including the wax and cement layers; often thin and inconspicuous, but sometimes very thick, ornamented, and obscuring the underlying cuticle; thick ceroteguments often can be peeled off to expose a very different-looking mite.
cervix (= calyx) - in phytoseioid Mesostigmata (Phytoseiidae, Blattisociidae, Otopheidomenidae, Podocinidae), a collar-like structure of the sperm access system which surrounds the base of the vesicle.
cf. - confer (L. conferre - refer or compare to) used for uncertain species designations (e.g. Cosmolaelaps cf. vacua (Michael)), roughly meaning 'see or compare to', and implying that the specimen referred to may represent a new species or may simply be an unusual form of the attributed species (see nr., sp. nr., and aff.).
chaetome - a complement of setae; the setal array present on a stage or body part.
chaetotaxy - the use of setal position and form in taxonomy; see Lindquist-Evans system, Grandjean system, Rostral-lamellar system, etc.
chambered - a structure with discrete compartments, e.g. the peritremes of some ologamasids (Mesostigmata) and prostigmatans.
chela - a pincer, as in a pseudoscorpion's distal pedipalpal segments.
chelate - pincer-like, as in a crab's claws, a scorpion's pedipalps or many chelicerae; in water mites (Hydrachnida), chelate palps have a dorsal palptibial process opposed to a ventral movable palptarsus (opposed to uncate).
chelate-dentate - pincer-like chelicerae with teeth.
chelate-serrate - pincer-like chelicerae with a row of saw-like teeth (also serrate). [Back to Top]
chelicera - a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts. In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms. In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments. Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
cheliceral - of or pertaining to the chelicera.
cheliceral guides (= outer infracapitular stylets) - a pair of capitular processes that frame the cheliceral stylets in the Eriophyoidea.
cheliceral retainer - the flexible, spine-like structure produced by the palpcoxal base and enclosing the cheliceral stylets in Eriophyoidea.
cheliceral seta - any seta on the chelicera of a mite; the often scale-like or otherwise modified seta on the dorsal surface of the chelicera in Mesostigmata.
cheliceral sheath (= stylet sheath, rostral gutter) - the median anterior process of the capitulum bearing a gutter, U-shaped in cross section, that enclosed the 7-9 stylets in the Eriophyoidea.
chelicerate - a member of the arthropod lineage Chelicerata that includes the horseshoe crabs, scorpions, spiders, mites and their relatives.
cheyletid - a member of the family Cheyletidae (Prostigmata). Most members of the subfamily Cheyletinae are predatory and sometimes important in biocontrol; members of the Cheyletiellinae (sometimes given its own family) are parasites of birds.
cheyletiosis - a mange caused by infestation by species of Cheyletiella (Prostigmata: Cheyletidae), host-specialists that live on the epidermis of small to medium sized mammals: C. yasguri Smiley is associated with dogs, C. blakei Smiley infests cats, and rabbits are host to C. parasitivorax (Mégnin). Infestations of pets and lab animals can be without symptom, but in severe cases pruritis, hair loss, and crustose lesions can develop. Species of Cheyletiella are highly active mites, and their skin-like color and rapid scampering has given them their common name, walking dandruff.
chigger - the parasitic larval stage of a member of the Trombiculoidea (Prostigmata, Parasitengona) that feed on the skin of vertebrates causing dermatitis (see trombidiosis) and some of which transmit scrub typhus. Nymphs and adults feed on small arthropods and their eggs and are often brightly colored, and densely hairy (velvet mites).
Chilean predatory mite - the phytoseiid mite Phytoseiulus persimilis Athias-Henriot, a commercially available and extremely efficient predator of spider mites. Also called persimilis or the predatory mite.
circumanal setae - in Mesostigmata, the three setae (postanal and pair of peranal) setae surrounding the anal opening.
circumcapitular furrow - the flexible articulation joining the capitulum (gnathosoma) to the body (idiosoma).
circumgastric scissure (furrow) - the flexible articulation that joins the notogaster to the ventral plate in brachypyline oribatid mites.
Claparède's organ - an osmoregulatory organ located between legs I-II in the prelarvae and larvae of many acariform mites; s (= urstigma, also urpores, bruststiele). The serially homologous genital papillae are present in nymphs and adults whose larvae have Claparède's organ (Oudeman's Rule). Tydeid mites may retain the urstigmata beyond the larval stage. [Back to Top]
claw-like - having a distal hook; resembling a claw.
clunals - the 5th dorsocentral setae (DC5 = h1 or f3) in the Prichard & Baker System. Also see below.
clunal setae - in Mesostigmata, setae J5, which are usually the most posterior pair of median opisthonotal setae.
clavate - with a terminal knob or swelling; club-shaped; globose; capitate.
coalesced - united, grown together, as for example, the genital and anal regions of some prostigmatans.
cocoon - a silken sack spun by some acariform mites in which molting takes place.
cohort - a taxon of mites between the subordinal and superfamily levels.
collar traechae - obsolescent term used for the peritremes in spider mites and their relatives.
colliculate - having a pattern resembling fish scales; usually used for a raised, rounded and reticulate-like ornamentation on shields, especially in Mesostigmata.
comb claws - usually bipectinate or biserrate claws or empodia, as for example in teneriffiid mites (Prostigmata).
comb seta - pectinate setae on the palps of cheyletid mites (Prostigmata)
companion seta - a seta closely associated with a solenidion, sometimes sharing the same insertion.
condylophore - (Gr kondylos = knuckle + phor = to carry) - in Acariformes, a pair of internal sclerotized structures involved in the articulation of the empodial (e.g. Astigmata) and lateral claws.
conoid discs - two pairs of structures on the sucker plate of astigmatan deutonymphs (hypopi).
corniculus (pl. corniculi) (also, external malae) - a usually horn-like process (sometimes toothed, bifurcate, trifurcate, spine-like, spatulate, or membranous) on the subcapitulum of parasitiform mites that usually supports the salivary styli. A toothed corniculus could be confused with a rutellum, a possibly homologous structure in Acariformes and Opilioacarida.
costula - a longitudinal ridge or set of ridges on the prodorsum of some oribatid mites, similar to lamellae but without a projecting edge or cusp. [Back to Top]
coxa - the basal segment of the leg, articulating with (Parasitiformes) or fused to (Acariformes) the body wall.
coxal fields - the venter of acariform mites where the coxae have fused to the body wall covering the sternal region.
coxisternal plate - a sclerotized plate in the coxisternal region.
coxisternal seta - a seta in or between the coxisternal plates and numbered from coxa I-IV e.g. 1a-c, 2a-c, 3a-c, 4a-c
coxisternum - floor of the podosoma that serves to support the legs, composed of the fused coxae (epimera I-IV).
cribrum - the spiculate area posterior to and often lateral to the anal opening on the shield bearing the anal opening and circumanal setae in Mesostigmata.
crista - a crest-like or tooth-like ridge, especially a pair of such on the notogaster of some oppioid oribatid mites.
crista metopica - the often narrow prodorsal sclerite bearing 1-2 pairs of trichobothria in parasitengone mites.
Cryptostigmata - (Gr kryptos = hidden) an obsolete term for the Oribatida.
cyclamen mite - Phytonemus (aka Steneotarsonemus) pallidus (Banks) a plant-parasitic tarsonemid mite.
cunaxid - a predatory mite in the family Cunaxidae (Prostigmata); sometimes, but not always, a snout mite; some species are bright red and have large raptorial palps, others are pale to brownish in color and have short palps, but both types usually have a distinctive neck between the capitulum and idiosoma.
cuneate - ending in a wedge-shaped process.
cuneiform - wedged-shaped, as in ancient writing systems that used wedge-shaped characters.
cuticular lobes - the pattern of minute, raised processes that ornament the plicate ridges in the cuticles of many mites.
d - a designation used for setae on segment D in the Acariformes, e.g. d1-2. (See Grandjean system.)
D - a designation used for the second region (apparent segment) of the hysterosoma in Acariformes. (See Grandjean system.)
D1-5; DC1-5 - Dorsocentral opisthosomal setae of spider mites in Pritchard & Baker (1955. A revision of the spider mite family Tetranychidae. Mem. Pac. Coast Entomol. Soc. 2: 1-472.). D1 = c1; D2 = d1; D3 = e1; D4 = f1; D5 = h1 in the Grandjean system.
deficient - in relation to setae, reduced from a presumed holotrichous number.
dendritic - branching like a tree or bush, aborescent. [Back to Top]
denticles - small tooth-like processes, e.g. on the subcapitula of ticks and many mesostigmatans.
denticulate - bearing small, sharp processes, e.g. the hypostome of ticks.
Dermanyssina (also Dermanyssiae) - a lineage of Mesostigmata defined by the possession of a secondary sperm access system in the female and a spermatodactyl in the male. Dermanyssina includes most of the Mesostigmata likely to be encountered including macrochelids, phytoseiids and dermanyssoids.
dermanyssoid - a member of the Dermanyssoidea (Mesostigmata). Most dermanyssoids are parasitic on vertebrates, but some (e.g. species of Varroa, Tropilaelaps) are parasites of honeybees or other insects. Members of the Hypoaspidinae (=Hypoaspididae) are primarily free-living predators including species useful in biocontrol in the genera Geolaelaps, Stratiolaelaps, and 'Hypoaspis'.
deutogyne - overwintering or aestivating form of eriophyoid mites; morphologically distinct from the normal or protogyne form.
deutonymph (also deuteronymph) - the second nymphal stage or instar.
deutosternum - the sternum of the second body segment (pedipalps); the basis capitulum in parasitiform mites.
deutosternal denticles - rows of small teeth-like projections (often irregular and sometimes reduced to a single tooth) running transversely across the deutosternal groove and sometimes onto the lateral faces of the subcapitulum.
deutosternal gutter (also groove, hypognathal groove, subcapitular groove) - the median longitudinal gutter running on the subcapitulum of parasitiform mites that receives the tritosternum.
diarthric - a subcapitulum with a more or less transverse articulation that reaches the lateral margin at the base of the palp.
dichoid - a body appearing to be divided between legs II-III by a flexible sejugal furrow (Acariformes).
dichoidy - having the body articulated between legs II-III by a flexible sejugal (protero-hystersomatic) furrow (Acariformes). (See also trichoidy, ptychoidy, holoidy).
digitus fixus - see fixed digit.
disjugal plane (furrow) - the plane separating the ancestral prosoma and opisthosoma, usually not clearly present in mites and often confounded with the sejugal furrow.
distad - towards the free end of an appendage; the part of a leg or palp segment farthest from the body.
distal - towards the free end of an appendage.
divided dorsal shield - in Mesostigmata, adult mites have two usually subequal dorsal shields.
domatia - see acarodomatia.
dorsal - relating to the upper or back side; opposed to ventral.
dorsal hexagon - a fancied hexagonal area staked out by setal pairs j5, z5 and j6 in the podonotal region of many mesostigmatans; useful for orienting to setae to determine designations (see Lindquist-Evans system); setae j3-5 may also form a hexagonal array.
dorsal lyrifissure - the dorsal lyrifissure posteriad the cheliceral seta in Mesostigmata.
dorsal seta - any seta on the dorsum; in the Eriophyoidea the scapular seta sc.
dorsal seta I - in the Eriophyoidea, the external vertical seta ve.
dorsal seta II - in the Eriophyoidea, the scapular seta sc.
dorsocentrals - Dorsocentral (DC or D) opisthosomal setae of spider mites in Pritchard & Baker (1955. A revision of the spider mite family Tetranychidae. Mem. Pac. Coast Entomol. Soc. 2: 1-472.). DC1 = c1; DC2 = d1; DC3 = e1; DC4 = f1; DC5 = h1 in the Grandjean system.
dorsolaterals - Dorsolateral (L) opisthosomal setae of spider mites in Pritchard & Baker (1955. A revision of the spider mite family Tetranychidae. Mem. Pac. Coast Entomol. Soc. 2: 1-472.). L1 = c2; L2 = d2; L3 = e2; L4 = f2 in the Grandjean system.
dorso-sejugal suture (dorsosejugal groove) - a suture marking the fusion of the prodorsum and notogaster; the anterior portion of the circumgastric scissure. NB - this term is often misapplied to a flexible juncture or furrow.
dorsum - the upper or back side; opposed to venter.
duplex setae - a pair of setae or a seta and a solenidion sharing the same insertion.
e - a designation used for setae on segment E in the Acariformes, e.g. e1-2. (See Grandjean system.)
E - a designation used for the third region (apparent segment) of the hysterosoma in Acariformes. (See Grandjean system.)
earth mite - a member of the Penthaleidae (Prostigmata: Eupodoidea), including major plant pests in the redlegged earth mite (Halotydeus) and the blue pea-winter grain mite (Penthaleus) genera, or related families with red legs and black to dark green bodies. In reality, the entire cuticle is reddish, but the dark body contents obscure the body color.
edentate - with out teeth; usually referring to chelicerae.
elattostase (adj. elattostatic) - one of the abnormal stases recognized by Grandjean where the mouthparts are not functional but the legs are, e.g. prelarvae of some Anystina and Nanorchestidae; the deutonymph in Astigmata.
elbowed - bent as in the arm at the elbow; geniculate.
Eleutherengonides (also Eleutherengonida, Eleutherengonina) - a taxon in the Prostigmata comprised of the Raphignathina and the Heterostigmata. The Eleutherengonides includes many of the most important plant-parasitic mites (e.g. spider mites, broad mite, cyclamen mite).
emergent - rising above, projecting, as in the peritremes of some Prostigmata which range from small bumps to elongate processes.
empodium (empodia) - an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
Endeostigmata - a paraphyletic assemblage of early derivative sarcoptiform mites that has often been misplaced in the Prostigmata. Ten families are currently recognized, including the widespread and common Nanorchestidae, Bimichaeliidae, Alicorhagiidae, and Terpnacaridae. Most endeostigmatans are fungivores, algivores or feed on minute, soft-bodied invertebrates such as nematodes.
endeostigmatan - a member of the Endeostigmata; characteristic of or belonging to the Endeostigmata.
endeostigmatic - adjectival form of Endeostigmata. [Back to Top]
endeostigmatid - incorrectly formed, but commonly used, adjectival form of Endeostigmata.
endogynal (also endogynial, perigynum) processes (sclerites) - sclerotized structures lying under the genital shield, especially in early derivative Mesostigmata such as Parasitidae, Zerconidae and Trigynaspida (see vaginal sclerites). These structures may be simple or highly elaborated.
endogynum - the endogynal processes; internal sclerotized genitalic characters.
endopodal shield (elements) - narrow, strap-like, angular to subtriangular sclerites produced around the bases of the coxae in Mesostigmata; the anterior endopodal shields (I, II) are often fused to the sternal shield.
engorged - swollen from feeding as in a tick or chigger.
entire - a shield or sclerite with a continuous margin without incisions.
ep - the epicoxal of the palpcoxa in acariform mites.
ep1 - the epicoxal seta of coxa I in acariform mites.
epiandrum - a large, concave intercoxal region containing the male genital opening in the Holothyrida.
epicoxal seta - a minute, usually peg-like seta on the dorsal face of the palpcoxa (ep) or coxae of legs I (ep1) in some acariform mites.
epigynal (also epigynial) - of or relating to the female genital opening or a shield protecting it.
epigynum (also epigynium)- the external genital opening in the female; also used for the ovipore in Dermanyssina (which have a secondary female genital system).
epimere (pl. epimera) (also epimeron) - in oribatid mites, a sclerotized coxal field; in Astigmata, anterior coxal apodeme.
epimerite - in Astigmata, the posterior coxal apodeme.
epimorphic - possessing the definitive number of segments on hatching. Opposed to anamorphic.
ε (epsilon) - designation for the famulus on the tarsi of some acariform mites.
epistome - in acarology this usually refers to the gnathotectum of the Mesostigmata. [Back to Top]
ereynetal organ - a solenidion in a pouch-like recess in the tibiae of certain ereynetid mites (Prostigmata: Ereynetidae).
erineum (pl. erinea) - the open, fleece-like galls produced by some eriophyoid mites (Prostigmata: Eriophyoidea)
erinose mite - prostigmatans in the Eriophyoidea that produce galls that resemble dense aggregations of hairs (resembling fleece).
eriophyid (eriophyoid) - of or relating to a member of the family Eriophyidae (superfamily Eriophyoidea) which contains minute, worm-like and quadripod mites that cause galls, erinea, and other damage to plants.
euanal setae - setae borne on the anal valve (Parasitiformes).
eugenital setae - setae originating within the genital vestibule (Acariformes).
eupathidion (pl. eupathidia) - an optically active but hollow seta with a pore at its tip and found on the palptarsus or leg I tarsus of many acariform mites; probably a chemoreceptor; designation = zeta (ζ). (Also acanthoides).
euryxenic (-ous) - using a broad range (e.g. of habitats or hosts); a host or habitat (etc.) generalist.
Evans leg chaetotactic system - in Mesostigmata, the nomenclature for the setation of legs segments derived by GO Evans. In essence, the leg is visualized oriented dorso-ventrally and at a right angle to the body midline, such that four aspects are present: dorsal, ventral, anterior lateral, and posterior lateral. Setae are designated in rows for their anterior (ad) or posterior dorsal (pd), ventral (av, pv) or lateral (al, pl) aspects and numbered from distal to basal. For example, a segment with 2 rows of 3 dorsal setae would have three anterior dorsal (ad1-3) and three posterior dorsal (pd1-3) setae. Evans devised a similar system for the palps.
exopodal shield - usually narrow, strap-like sclerites, sometimes broader, produced around the lateral bases of the coxae in Mesostigmata; sometimes fused to the peritrematal shield.
external hypostomal (also hypostomatic) setae - usually the most lateral (h2) of the three pairs of hypostomatic setae in the Mesostigmata; present in the larva.
external malae - the corniculi.
external scapular seta - prodorsal seta sce (also se or s2) in Acariformes. [Back to Top]
external vertical seta - prodorsal seta ve (also se or s2) in Acariformes.
excrescence - (1) a brush-like, dendritic or otherwise elaborated processes produced from openings in the movable digit in trigynaspid and some microgyniine Mesostigmata; (2) an encrusted covering or outgrowth-like structure.
exuviae (pl. exuviae) - the outer layer of skin not recycled during a molt; empty exuviae are a sign of previous mite development on a substrate; some oribatid mites retain the dorsal notogastral portion of exuviae as a pagoda-like pile of scalps. (NB: the use of 'exuvia' as a singular makes no more sense than 'cloth' for 'clothes'.)
f - a designation used for setae on segment F in the Acariformes, e.g. f1-2. (See Grandjean system.)
F - a designation used for the fourth region (apparent segment) of the hysterosoma in Acariformes. (See Grandjean system.)
falcate - curved and more or less sickle-shaped.
fallacis - the phytoseiid mite Neoseiulus (also Amblyseius) fallacis (Garman), a generalist predator used in a variety of cropping systems.
false spider mite - a member of the family Tenuipalpidae (Prostigmata), e.g. species of Brevipalpus. False spider mites share the stylophore and whip-like stylets of spider mites, but are usually protected by sclerotized plates and are often dorso-ventrally flattened, resulting in another common name: flat mites.
famulus - a hollow and optically active seta-like structure located near the base of the dorsum of tarsus I in acariform mites; designation = ε (epsilon).
fastigals (ft) - the most basal pair of dorsal tarsal setae on the tarsi of acariform mites (see whorl).
fatal flatulence - possibly apocryphal ability of some Parasitengona to expel a paralyzing gas from their anal opening when hunting springtails. [Back to Top]
featherclaw - the highly divided bipectinate empodial claw found in the Eriophyoidea.
feather mite - a member of the Astigmata that lives on bird feathers.
femur (pl. femora) - major leg segment between trochanter and genu; often subdivided into a basifemur and a telofemur.
festoons - the ornamentation in some ticks that resembles a series of loops around the margin of the body.
filiform - thread-like; long and narrow.
fissure - a narrow slit of soft cuticle or line of juncture in a sclerotized shield or leg segment.
fixed digit - the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
flat mite - a dorso-ventrally flattened member of the family Tenuipalpidae (Prostigmata), e.g. species of Brevipalpus. Flat mites share the stylophore and whip-like stylets of spider mites, but are usually protected by sclerotized plates; also called false spider mites.
foliose - leaf-like; usually describing flattened, oval to rectangular setae with or without other ornamentation.
fossa (pl. fossae) - a pit or recessed area in the integument (also see pedofossa).
fova pedales (pl. = fovae pedales) - a pedofossa, a pit in the cuticle into which the legs can be withdrawn in some Mesostigmata, especially Uropodidae.
foveate - ornamented with large circular depressions.
foveolate - ornamented with small circular depressions; approaching punctate.
fowl mite - a member of the Dermanyssoidea (Mesostigmata) parasitic on birds, especially the poultry red mite (Dermanyssus gallinae (de Geer)), the northern fowl mite (aka Starling mite - Ornithonyssus sylviarum (C&F)), or the tropical fowl mite (Ornithonyssus bursa (Berlese)). [Back to Top]
fragmented - broken up, composed of several discrete parts rather than of a single unit.
frontal seta - in the Eriophyoidea, the unpaired, median internal vertical seta vi.
ft - designation for the fastigals, the most basal pair of dorsal tarsal setae on the tarsi of acariform mites (see whorl).
fundamental (as in fundamental chaetome) - a seta or other structure present in the larval stage.
g - a designation used for genital setae, e.g. g1.
gabelzhan - in Mesostigmata, the offset and usually most distal tooth on the fixed digit (German: Gabel [fork tine] and zahn [tooth].
gall mite - a species of Eriophyoidea that produces galls on plants.
gaster - the idiosomal venter.
gdj, gds, gdz - designations for podonotal glands associated with particular setal rows based on the works of Krantz & Redmond (1987: Identification of glandular and poroidal idionotal systems in Macrocheles perglaber F & P (Acari: Macrochelidae). Exp. Appl. Acarol. 3: 243-253) and Johnston & Moraza (1991: The idiosomal adenotaxy and poroidotaxy of Zerconidae (Mesostigmata: Zerconina). pp. 349-356 in Dusabek & Bukva (eds) Modern Acarology Vol. 2).
gdJ, gdS gdZ - designations for opisthonotal glands associated with particular setal rows based on the works of Krantz & Redmond (1987: Identification of glandular and poroidal idionotal systems in Macrocheles perglaber F & P (Acari: Macrochelidae). Exp. Appl. Acarol. 3: 243-253) and Johnston & Moraza (1991: The idiosomal adenotaxy and poroidotaxy of Zerconidae (Mesostigmata: Zerconina). pp. 349-356 in Dusabek & Bukva (eds) Modern Acarology Vol. 2).
geniculate - with an elbow- or knee-like bend.
genital acetabulum (pl. acetabula) - an invagination containing the genitalia; also sometimes used for the genital papillae, especially in the Hydrachnida.
genital aperture - the genital opening or acetabulum.
genital disc - see genital papillae.
genital lamella - a small process that may cover the base of the tritosternum in male Parasitidae (Mesostigmata)
genital orifice - the male genital opening; in Mesostigmata the genital orifice is usually subcircular, located in the intercoxal region (often at the base of the tritosternum), and has 1-2 valves.
genital papillae - 1-3 pairs of extrusible finger-like to button-like projections, usually retracted into in the genital vestibule of acariform mites; sometimes formed as sessile disks around the genital opening; thought to be osmoregulatory structures; modified or multiplied and dispersed over the body in many freshwater mites. Genital papillae are absent in the larva, but may be added ontogenetically: protonymphs have one pair, deutonymphs two pairs, and tritonymphs (and adults) three pairs. The tritonymphal pair of papillae is often lost. The serially homologous Claparède's organ is usually present in the larvae (and prelarvae) of mites exhibiting genital papillae in nymphs and adults (Oudeman's Rule).
genitals - 1st genitals or anteromedial genitals (= g1) and 2nd genitals or posterolateral genitals (= g2) in the Pritchard & Baker System.
genital seta - a seta on a genital shield or valve; seta st5 in the Mesostigmata; the genitals g1-g2 in spider mites; in the Eriophyoidea, coxisternal seta 3a.
genital shield - a shield or shields covering the genital opening; in female mongynaspine Mesostigmata this shield is usually called the epigynal (epigynial) shield. [Back to Top]
genital sucker - see genital papillae.
genital valves - sclerites covering the genital opening; usually referring to small sclerites (larger ones are usually called 'shields' or 'plates'.
genital vestibule - the ventral chamber containing the genital papillae and genital opening and closed by a pair of genital valves.
genitiventral shield (= opisthogenital shield) - in Mesostigmata, an epigynal shield that extends back over the ventral region but is separate from the anal shield, e.g. in Pseudoparasitus spp. (Laelapidae), and leaves any metapodal elements free.
genu (pl. genua) (= patella) - the 4th leg segment, between the femur and tibia.
gestalt - the overall form or concept; the whole animal, habitus; usually used to describe how one knows the identity of a mite even if they can't specify the diagnostic characters (German = ge'-shtailt).
gland - usually referring to a glandular opening in the cuticle such as the lateral opisthonotal glands in the Sarcoptiformes or the idionotal glands in the Mesostigmata (see gdj etc. above), including hypertrophied openings that produce defensive secretions.
glandularium (pl. glandularia) - the gland complex in water mites (Hydracarina); on the surface these consist of the gland openings and associated trigger hairs, often carried on a small sclerite.
globose - spherical.
gnathosoma (= capitulum) - - the anteriormost part of a mite or ricinuleid, composed of the cheliceral and pedipalpal segments and separated from the body (idiosoma) by a ring of soft cuticle.
gnathosomal capsule - a fusion of the gnathosomal elements (chelicerae and subcapitulum) into a single structure, as seen in protigmatans such as Heterostigmata, Myobiidae, and Cheyletoidea (also tegmen).
gnathotectum (= epistome, tectum) - an often membranous dorsal projection of the anterior margin of the basis capitulum in Mesostigmata; often diagnostic at family-, genus- or species-levels; also often difficult to see without high magnification and good optics.
Gr - abbreviation used for 'Greek' in this Glossary. [Back to Top]
Grandjean system - the primary system for designation of hysterosomal setae used in the Acariformes. Hypothesized segments (anterior to posterior) are C, D, E, F, H, PS (pseudanal), AD (adanal), AN (anal) and PA (peranal) (see anamorphosis). 'G' is not used to avoid confusion with the genital segment, which is treated separately. Setae are designated from the midline to the sides from 1-x, e.g. c1, c2, c3, c4 (also cp).
h - a designation used for setae on segment H in the Acariformes, e.g. h1-3 (see Grandjean system); also a designation used for the hypostomal (hypostomatic) setae (h1-3) in Mesostigmata.
H - a designation used for the fifth region (apparent segment) of the hysterosoma in Acariformes. (NB - H comes after F and before PS, 'G' is not used to avoid confusion with the genital region). (See Grandjean system.)
H - the humeral seta of spider mites in the Pritchard & Baker system; H = c3 in the Grandjean system.
habitus - a view of the entire animal.
hair - usually referring to a seta; considered an imprecise and misleading term for seta.
Haller's organ - the array of sensory setae in a pit and depression on tarsus I of ticks; similar structures on holothyrans and some mesostigmatans.
hemispherical - roughly half a sphere; used to describe the habitus of some mites.
heterodactyly - having claws of different size or form.
heteromorphic - having different morphological forms; referring either to different forms within a particular life stage (e.g. normal and heteromorphic deutonymphs in some Mesostigmata; protogynes vs deutogynes in Eriophyoidea) or a developmental stage that differs radically from other stages (e.g. the heteromorphic deutonymph or hypopus in the Astigmatina).
heterostigmata - the sexually dimorphic (present in females, absent in males) condition of the stigmatal-tracheal system in the Heterostigmatina.
Heterostigmatina (also Heterostigmata) - a lineage of Prostigmata that includes the tarsonemid mites and their close relatives.
hexapod - with three pairs of legs (i.e. 6 legs), as in the larvae of mites or the larviform stages of others.
holodorsal shield - a shield that covers all of the dorsum. In Mesostigmata, the holodorsal shield is often interpreted as resulting from the fusion of podonotal and opisthonotal shields and a suture between these regions is often visible (see recurved and procurved).
hologastric shield - in Mesostigmata, a shield that covers the genital, ventral and anal regions; a ventrianal shield that incorporates the metapodal elements and is fused to the epigynal shield. [Back to Top]
holoventral shield - in Mesostigmata, a shield that covers the entire venter of a male, including the intercoxal region (where it bears the genital aperture), the ventral region and the anal region.
holoid - lacking flexible cuticle between legs II-III.
holotrichous - adjectival form of holotrichy.
holotrichy - having the complete complement of setae thought to have been present in the ancestor of a group (Gr holos = entire + trich = hair); opposed to neotrichy (new hairs) or hypertichy (too many hairs).
hook (as in cheliceral hook) - the distal hook-like tips of chelicerae in the Mesostigmata, as opposed to cheliceral teeth.
honeybee tracheal mite - Acarapis woodi (Rennie) a tarsonemid mite that lives parasitically in the tracheae of honeybees and is associated with the development of Isle of Wight Disease. Other species of Acarapis live externally on bees.
horn - any horn-like process, but in Mesostigmata often referring to a posterior process of the idiosoma.
humeral process (projection) - any fixed projection in the humeral region; sometimes confused with pteromorphs in oribatid mites; lateral raised areas of the idiosoma associated with the peritreme in some uropodids (Mesostigmata).
humeral seta - a seta in the humeral ('shoulder') region, often projecting at a more or less right angle to the body; usually seta r3 (rarely r4) in Mesostigmata and H or c3 (rarely c4 = cp) in Acariformes.
hyaline - transparent, membranous, e.g. a hyaline sheath.
hyperphoresy - a phoretic mite transported on another phoretic organism.
hypertrichous - having more than the number of setae normally found in a group (Gr hyper = above + trich = hair); a more neutral term than neotrichy, which implies that the additional hairs have been added during the evolution of the group. (see also hypotrichous, holotrichous).
hypertrichy - the condition of being hypertrichous. [Back to Top]
hypopode - see hypopus.
hypopus (pl. hypopi) (also hypopode) - the heteromorphic deutonymph produced by many astigmatans, usually as a stage that is phoretic on insects and having a large ventral sucker plate. Hypopi lack functional mouthparts and the capitulum is reduced to a small nub bearing a pair of processes, but some appear to feed by absorbing fluids through their cuticles.
hypognathal denticles (deutosternal denticles) - rows of small teeth-like projections (often irregular and sometimes reduced to a single tooth) running transversely across the deutosternal groove and sometimes onto the lateral faces of the subcapitulum.
hypognathal groove (also hypognathal gutter, subcapitular groove deutosternal groove or gutter) - the median longitudinal gutter running on the subcapitulum of parasitiform mites that receives the tritosternum.
hypostomal (also hypostomatic) setae - the three pairs of setae on the hypostome of mesostigmatans; the anterior (h1) and external hypostomal (h2) setae are present in the larva; the internal hypostomal seta (h3) is added in the protonymph. These setae are arranged more or less longitudinally in most uropodines and tend to be in a triangular array in non-uropodine Mesostigmata.
hypostomal denticles (teeth, retrorse teeth) - the backwardly directed tooth-like projections on the elongate hypostome of ticks that are used to anchor the capitulum to skin while feeding.
hypostome - the anterior part of the subcapitulum (Gr hypos = under + stoma = mouth) in parasitiform mites that bears the corniculi and hypostomal setae; presumably the remnant of the palpcoxal endites. In the Eriophyoidea, a synonym for the capitulum (infracapitulum, rostrum, gnathosoma).
hypotrichous - having fewer than the number of setae normally found in a group (Gr hypo = below + trich = hair), e.g. phytoseiid mites (Mesostigmata) have 20 or fewer pairs of dorsal setae . (see also hypertrichous, holotrichous).
hysterosoma - idiosoma behind the sejugal furrow (plane) between legs II-III; opposed to the proterosoma.
hysterosomal (hysterosomatic) - adjectival form of hysterosoma. [Back to Top]
hysterosomatic (hysterosomal) - adjectival form of hysterosoma.
ia - designation for the anteriormost pair of cupules in acariform mites; typically lateral and associated with the border of segments C-D; also the antiaxial lyrifissure on the chelicera of Mesostigmata.
iad - designation for the posteriormost pair of cupules in acariform mites; typically ventral and associated with segment AD.
id - designation for the dorsal lyrifissure on the chelicera of Mesostigmata.
idj, ids, idz - designations for podonotal lyrifissures associated with particular setal rows based on the works of Krantz & Redmond (1987: Identification of glandular and poroidal idionotal systems in Macrocheles perglaber F & P (Acari: Macrochelidae). Exp. Appl. Acarol. 3: 243-253) and Johnston & Moraza (1991: The idiosomal adenotaxy and poroidotaxy of Zerconidae (Mesostigmata: Zerconina). pp. 349-356 in Dusabek & Bukva (eds) Modern Acarology Vol. 2).
idJ, idS idZ - designations for opisthonotal lyrifissures associated with particular setal rows based on the works of Krantz & Redmond (1987: Identification of glandular and poroidal idionotal systems in Macrocheles perglaber F & P (Acari: Macrochelidae). Exp. Appl. Acarol. 3: 243-253) and Johnston & Moraza (1991: The idiosomal adenotaxy and poroidotaxy of Zerconidae (Mesostigmata: Zerconina). pp. 349-356 in Dusabek & Bukva (eds) Modern Acarology Vol. 2).
idionotal - on the dorsum of the body (idiosoma).
idionymic - structures or stages that differ in discontinuous surface characters.
idiosoma - (Gr idios = distinct + soma = body) the main body tagma of mites, containing the opisthosoma and part of the prosoma. [Back to Top]
idiosomal (idiosomatic) - adjectival form of idiosoma.
idiosomatic (idiosomal) - adjectival form of idiosoma.
ih - designation for a pair of cupules in acariform mites; typically lateral and associated with segment H.
im - designation for second anteriormost pair of cupules in acariform mites; typically lateral and associated with segment E.
imagochrysalis - the tritonymphal stage in the Parasitengona; a calyptostatic cuticle formed within the deutonymphal cuticle in which the adult stage develops.
inner infracapitular stylets (= auxilary stylets) - a pair of stylets of uncertain origin in the bundle of 7-9 stylets in the Eriophyoidea.
inner sacrals - setae DC4 (= f1) in the Pritchard & Baker System
incised - cut into, e.g. a dorsal shield composed of podonotal and opisthonotal shields fused medially but free laterally.
infracapitulum - the capitulum or gnathosoma (sometimes used to indicate only the subcapitulum).
infundibulum - a depression in the cuticle associated with the opening of a gland; also a swelling of the tubulus under the solenostome in laelapid type sperm access systems.
inguinal pore plate - in gamasine Mesostigmata, a pair of small sclerites in the region of the posterior corners of the genital shield and parapodals IV that bears the inguinal glands gv2.
instar - (L = form) - an immature mite or other arthropod between molts (or from apolysis to apolysis for some authors), or between egg hatching and the first molt. Mites mostly have determinate growth and do not molt after reaching the adult stage; therefore, the adult is not considered an instar.
intercalary sclerite - in Mesostigmata, a small sclerite between the basitarsus and telotarsus on leg IV. May bear setae av4 and pv4.
intercoxal - between the coxae. In Parasitiformes, a sternal region lies between the bases of the legs and usually contains one or more sternal shields and at least the anterior portion of the genital shield. An intercoxal shield in male Mesostigmata is often called the sternogenital or sternitogenital shield because it bears the genital opening. In Acariformes, no sternal region is present and the coxae of the legs are fused to the venter and usually meet medially; genital openings are usually postcoxal, but may intrude between the fused coxal bases in Astigmatina.
internal hypostomal (also hypostomatic) setae - usually the most median (h3) of the
