acarinarium: A specialized morphological structure that facilitates retention of mites on the body of an organism, typically a bee or wasp.
adanal sucker: Paired pad-like structures situated near the anal opening in males of Astigmata. Originate from adanal setae. Serve for holding female during copulation. Also known as anal suckers and paranal suckers.
aedeagus: An external organ of a male arthropod that is specialized to deliver sperm during copulation.
ambulacrum: The claws and empodium of the apotele or pretarsus.
anal shield: In Mesostigmata, a ventral shield bearing the anal opening and circumanal setae (adanal or postanal setae), but without any ventral setae or pores (lyrifissures) on it. If ventral setae are present on shield than referred to as a ventrianal shield.
apodeme: Internal sclerite that serves as an attachment site for muscles. Most commonly used (as "coxal apodeme") to describe elements of coxae fused to the ventral body in Acariformes (coxae are free and not fused to the body in Parasitiformes), and may be variously referred to as ventral, sternal, anterior, or posterior.
apotele: The most distal leg or palp segment.
arthrodial brush: A brush-like extension of the arthrodial membrane at the articulation of the movable and fixed digits of the chelicera in some Mesostigmata. Not to be confused with cheliceral excrescences that are produced from openings in the movable digit.
attachment organ: Complex unpaired structure in phoretic deutonymphs of Astigmata situated on the posteroventral end of the body that serves for attachment to the host during phoresy. In deutonymphs phoretic on insects, attachment organ consists of a vestigial anal opening and two types of attachment elements: true suckers that create negative pressure and conoids that create adhesive forces. Not to be confused with pedicel.


bothridial seta: A modified seta inserted in a cup-like base (bothridium); forms include filiform and capitate. Also known as bothridial sensillum and trichobothrium.


chelicera: Anterior, paired appendage of the body. Primary organ for food acquisition, adapted for chewing, piercing, tearing, sucking, or filtering.
Claparède organ: Variously shaped, paired structures situated ventrally on coxae I or II or in the integument between them in larvae of many acariform mites. Homologous to the genital papillae of later ontogenetic stages. Variant spelling is Claparède's organ. In Parasitengona, also known as urstigma (pl. urstigmata).
condylophore: In Acariformes, pretarsal paired sclerotized structures arising from the distal end of the tarsus and forming a joint with lateral claws (in Endeostigmata, Oribatida and Trombidiformes) and the empodial claw. Not to be confused with vertical sclerites of Parasitiformes.
corniculus: Paired, horn-like process (sometimes toothed, bifurcate, trifurcate, spine-like, spatulate, or membranous) on the subcapitulum of parasitiform mites. These processes usually support the salivary styli. If toothed could be confused with a rutellum, a possibly homologous structure in Acariformes and Opilioacarida.
coxa: In Parasitiformes, most basal leg segment (or podomere) forming a joint with the body. Areas delimited by coxal apodemes are called coxal fields in Astigmata or coxisternal plates in Prostigmata.
cuticular sucker: Structures of cuticular origin on the attachment organ of phoretic deutonymphs of Astigmata, on which they are typically paired anterior, lateral, and posterior unpaired suckers that lack alveoli.


empodial claw: Claw-like, membranous, or pad-like structure of setal origin. Present only on the pretarsus in Acariformes. In Astigmata, it is the only claw on the pretarsus and often referred to simply as the claw. In the remaining Acariformes, may be accomanied by two lateral claws. Also known as empodium, pretarsal empodium, or central claw.
empodium: Here used only when empodial claw is not claw-like, i.e., it is pad-like or membranous.
endopodal shield: Small, narrow sclerites adjacent to coxal bases facing the midline of the body. Present in Mesostigmata.
epigynal shield: A shield protecting the female genital opening. Well-developed in Mesostigmata. Also known as epigynial shield.
exopodal shield: Small, narrow sclerites (or plates) adjacent to the external parts of coxal bases. Present in Mesostigmata.


femur: Leg or palp segment (also known as podomere or palpomere) between genu and trochanter. In ParasitIformes can be subdivided into telofemur and basifemur.
fungivorous: Feeding on fungi.


genital capsule: A caudal or ventrocaudal capsule in males of Pygmephoroidea, Pyemotoidea, and Tarsonemidae formed by consolidated plates H, PS, and Ag. In many mites with short, sclerotized aedeagus flanked by setigenous processes and surrounded by adhesive flange or disc.
genital papilla: Paired, eversible, finger- or bell-shaped structures situated under the genital valves (in the progenital chamber) of many Acariformes, which serve for osmoregulation. In feeding stages of Histiostomatidae (but not phoretic deutonymphs) these are modified to cuticular rings situated externally on the ventral body.
genu: Leg or palp segment (also known as podomere or palpomere) between tibia and femur.
gnathosoma: Division of body anterior to the propodosoma bearing two pairs of appendages (palps and chelicerae).
gonopode: An appendage specialized to transfer sperm, such as the modified male chelicera in Mesostigmata.
Grandjean's organ: Paired, finger-shaped, lobe-shaped, or otherwise elaborated structure situated on the lateral sides of the propodosoma, typically in association with the podocephalic canal. Its free edges may be strongly fimbriate.


kleptoparasite: An animal that takes prey or other food from another animal that has caught, collected, or otherwise prepared the food, including stored food. Both kleptoparasitic bees and kleptoparasitic mites feed on food provisioned in the host bee nest. Kleptoparasitic bees do not make their own nests; they stealthily deposit eggs in the nest of a bee host and can act as phoretic hosts for mites only because they deliver them to nests of actual bee hosts. Variant spelling: cleptoparasite.


labrum: An unpaired process that lies above and between the chelicerae.
lateral claw: Usually paired, claw-like structures, situated on each side of the empodial claw on the distal pretarsus in many Acariformes. Absent in all Astigmata. Sometimes referred to simply as claws.
latigynal shield: A pair of sclerites laterad the mesogynal shield in some female parasitiform mites, that help protect the genital opening; usually bearing one or more pairs of setae and sometimes fused to other genital or ventral elements. The single female genital shield in the Gamasina may represent a fusion of the latigynal and mesogynal shields. Also known as latigynial shield.


mesogynal shield: An unpaired median sclerite in some female parasitiform mites that helps protect the genital opening; usually nude and sometimes fused to other genital or ventral elements. The single female genital shield in the Gamasina may represent a fusion of the latigynal and mesogynal shields. Also known as mesogynial shield.
metapodal shield: In Mesostigmata, a pair (sometimes fused) of small sclerites posterior to coxae IV in the ventral region.
metasternal shield: Small, usually teardrop to subtriangular paired shields bearing metasternal setae st4; sometimes fused to the sternal shield or the endopodal shields. Present in Mesostigmata.


opisthogastric region: Ventral body behind legs IV. Also known as opisthogaster and ventral opisthosoma.
opisthonotal: Pertaining to dorsal opisthosoma.
opisthosoma: Body division posterior to legs IV; usually there is no distinct boundary delimiting this part of idiosoma.
ovipore: Opening of female which serves as an outlet for oviposition. In Astigmata and non-astigmatan Oribatida, situated between genital valves. In Astigmata, not to be confused with the copulatory opening (which serves for sperm intake).


palp: Second (after chelicera) paired appendage of the gnathosoma. Has a sensory function, but may be variously modified for other functions (e.g., raptorial, attachment to host, or filtering).
palpal apotele: In Mesostigmata a tined structure originating at the base of the palptarsus and thought to be a remnant of the claws. Also known as the palptarsal apotele.
pedicel: A stalk-shaped, hardened secretion of a specialized gland situated at the posteroventral body end that serves for attachment to the host during phoresy in Uropodina.
peridomestic: Of or pertaining to living in or around human habitations.
peritreme: Paired, tubular, elaborated extensions of a tracheal system associated with stigmatic openings. Can be chambered, arch-like, and situated on the bases of chelicerae as in Cheyletidae (Prostigmata) or, in Mesostigmata, linear and situated on the lateral sides of the body.
pharynx: A muscular ectodermal structure that opens into a buccal cavity or mouth, and serves as a suction pump for ingesting food materials. In certain Heterostigmata pharyngal musculature is subdivided into 2-3 distinct parts.
phoresy: Attaching to or boarding another organism (i.e., a host) for dispersal to new habitats. Can be distinguished from parasitism because feeding typically does not occur.
phoretic: Pertaining to phoresy; using another organism (i.e., a host) for dispersal to new habitats. Phoresy can be distinguished from parasitism because feeding typically does not occur during phoresy.
phoretic deutonymph: An active nymphal stage in Astigmata that serves for dispersal on arthropod or vertebrate hosts. A subtype of heteromorphic deutonymph. See Life stages page for more details.
physogastric: With entire body or only opisthosoma swollen to hold massive numbers of eggs or developing young.
pilus dentilis: A seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
pinnaculum: A subapical, dorsal elevation on tibiotarsus I bearing a distinct cluster of 2-3 rodlike sensory setae. Term is used for Heterostigmata only.
pollenkitt: A sticky covering found on the surface of pollen grains.
presternal shield: Small, paired sclerotized plates anterior to the sternal shield and laterad or posteriad the base of the tritosternum in some Mesostigmata. Also known as presternal platelets.
pretarsus: Terminal leg or palpal segment distal to tarsus.
prodorsal: Pertaining to the prodorsum.
prodorsum: Dorsal surface of propodosoma.
progenital chamber: Cavity covered by genital valves in Astigmata; contains genital papillae. Usually not visible on regular microscopic preparations. Absent in feeding stages of Histiostomatidae.
progenital sclerite: A paired or unpaired sclerite situated anterior to the oviporus (female) or genital apparatus (male). In some astigmatid females it is a single, enlarged sclerite, which is often called an epigynum in descriprive works.
propodonotal: Pertaining to dorsal propodosoma (prodorsum).
propodosoma: Anterior part of idiosoma, in front of sejugal furrow.
propodosomal shield: Unpaired shield situated on the dorsal propodosoma.
propolis: A red or brown resinous substance collected by honey bees from tree buds that is used by them to fill crevices and to seal and varnish honeycombs.
protonymph: Ontogenetic stage between larva and deutonymph. See Life stages page for more details.
pulvillus: a membranous, pad-like structure associated with the claws in Mesostigmata.


saprophagous: Feeding on dead or decaying organic matter.
sclerite: A component section of an exoskeleton; a plate forming the skeleton of an arthropod.
sejugal furrow: Furrow separating propodosoma and hysterosoma in acariform mites.
simple: Of claws or setae; not modified or not bi- or trifurcate at tip.
solenidion: Thin-walled, terminally rounded or pointed filiform or peglike structure that is not birefringent in polarized light (unlike common setae in Acariformes). Often appears striated because of its internal structure. Found on the palpal tarsus on the gnathosoma and may also occur on the tarsus and tibia, less frequently on the genu, and occasionally on the femur of legs I-IV. In Acariformes, leg solenidia often arise from unsclerotized areas.
spermatheca: A structure in the female for storing sperm, typically sac-like.
spermatodactyl: The "sperm finger" on the chelicerae of male Dermanyssina (Parasitiformes) used to transfer sperm to the secondary sperm system in the female. Has various forms, from simple finger-like processes to very long, contorted structures.
spermatophore: Any structure that carries a packet of sperm.
spermatopositor: A small male organ for depositing spermatophores.
sporotheca: Internal paired sacks or external pouch serving for transferring fungal spores. In bee-associated mites, recorded in Trochometridium (paired sacks between coxae III and IV of females); certain Imparipes (Scutacaridae; paired sacks posterior to coxae IV of females); and Sennertia hipposideros-groups (hysterosomal pouch in phoretic deutonymphs).
sternal shield: A shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
stigmatic opening: An opening that connects to a well-developed tracheal system (exceptions exist when tracheal system and stigmatal openings are disassociated). Situated at or on the cheliceral bases, anterolaterally on the propodosoma, or lateral sides of the body. Also known as stigmatal opening or stigma (pl. stigmata).
subcapitulum: Ventral faces of the fused palpcoxae.
subcortical: Under tree bark.
supracoxal gland: Paired glands serving for maintenance of water balance in Astigmata. These glands are usually invisible on typical microscopic preparations. However, their presence can be detected by the well-sclerotized supracoxal gland openings, which are situated on supracoxal sclerites.


tarsus: Terminal segment (also known as podomere or palpomere) of legs or palps. In Parasitoformes it can be subdivided into telotarsus and basitarsus.
tectum: The leading dorsal, shelf-like projection of the basis capitulum in Mesostigmata. Also known as gnathotectum or epistome.
tegula: Lobe-like to acuminate cuticular plate projecting posteriorly between coxae IV in Tarsonemidae. Also used for hinged sclerite covering the wing bases in bees.
tibia: Leg or palp segment (also known as podomere or palpomere) between tarsus and genu.
trichobothrium: Modified seta that can be distinguished from true seta by its distinct large socket (complex cup-like cavity), and often, shape (which may be filiform, ciliate, pectinate, or thickened or clubbed). Present in many Acariformes (except Astigmata) and Opilioacarida (Parasitiformes). When paired and situated on the propodosoma, termed "prodorsal."
tritonymph: Ontogenetic stage between the deutonymph and adult. Sometimes this stage is absent and deutonymph transforms directly to the adult stage. See Life stages page for more details.
tritosternum: In Mesostigmata, a biflagellate structure situated on the ventral side of the body, posterior to the gnathosoma and anterior to the sternal shield. Sometimes the flagellae (laciniae) are partially or completely fused.
trochanter: Leg or palp segment (also known as podomere or palpomere) between femur and coxa. In Acariformes this is the most basal movable leg segment (or podomere) forming a joint with the body.


ventrianal shield: In Mesostigmata, a ventral shield bearing the anal opening, circumanal (postanal and adanal) setae, and one or more pairs of ventral setae or pores (lyrifissures) (see anal shield); may be narrow or very broad and covering most of the gaster.


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