Primagistemus Fan &amp; Zhang 2002, gen. nov.
Creators: name: Fan, Qing-Hai
name: Zhang, Zhi-Qiang
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Prostigmata
Stigmaeidae
Primagistemus

description: Genus <i>Primagistemus</i> gen. nov. Type species: <i>Stigmaeus loadmani</i> Wood, 1967: 102; based on adult females. <i>Description of adults (Figs. 1­17)</i>. Idiosoma oval in dorsoventral view. Chelicerae separate. Palp robust; tibial claw slightly shorter than palptarsus; accessory claw slender. Terminal palptarsal eupathidia fused basally at insertion point and distally divided into 3 minute prongs. Fundamental setation from palptrochanter to palptarsus on adult: 0, 3, 1, 2 + 1 claw + 1 accessary claw, 4 + 1 1 subterminal spine­like eupathidium + 3 basally fused eupathidia. Subcapitulum with 2 pairs of setae (<i>m</i> and <i>n</i>), both posterolaterad of pharynx, <i>m­m</i> wider than <i>n­n</i>. Propodosoma covered with a large triangular shield, which bears 1 pair of eyes and 4 pairs of setae (<i>vi</i>, <i>ve</i>, <i>sci</i>, <i>sce</i>), <i>sci</i> mediad of <i>sce</i>; postocular body absent. Central hysterosomal shield well sclerotized, bearing 3 pairs of setae (<i>c</i> <i>1</i>, <i>d</i> <i>1</i>, <i>e</i> <i>1</i>). Setae <i>c</i> <i>2</i>, <i>d</i> <i>2</i>, <i>e</i> <i>2</i> and <i>f</i> <i>1</i> situated on small platelets. Suranal shield (H) integral, bearing 2 pairs of setae (<i>h</i> <i>1</i> and <i>h</i> <i>2</i>). Endopodal shields present around coxae I and II, but absent around III and IV. Ventral setae 3 pairs (<i>1 a</i>, <i>3 a</i> and <i>4 a</i>). Aggenital setae 3 pairs (<i>ag</i> <i>1</i>, <i>ag</i> <i>2</i> and <i>ag</i> <i>3</i>). Genital and anal openings contiguous, with 1 pair of genital setae (<i>g</i> <i>1</i>) and 3 pairs of pseudanal setae (<i>ps</i> <i>3</i> <i>, ps</i> <i>2</i> and <i>ps</i> <i>1</i>) on adult female. Leg tarsal claws well developed, without a prominent membranous arolium. Empodium rod­like, bearing 3 Y­shaped tenent hairs. Fundamental setation of legs I­IV on adult female: coxae 2, 1, 2, 2; trochanters 1, 1, 1, 0; femora 5, 4, 3, 2; genua 3 + 1, 2, 0, 0; tibiae 5 + 1 p, 5 + 1 p, 5 + 1 p, 5 + 1 p; tarsi 13 + 1, 9 + 1, 7 + 1, 7 + 1. <i>Etymology</i>. The generic name <i>Primagistemus</i> is combined from the Latin prefix “ <i>primi</i> ” (primal) and the generic name, <i>Agistemus</i>. It is masculine in gender. <i>Taxonomic position</i>. Mites of the genus <i>Primagistemus</i> have 4 pairs of setae on the propodosomal shield, like those in some genera (e.g. <i>Stigmaeus</i>, <i>Pseudostigmaeus</i>, <i>Summersiella</i>, <i>Eustigmaeus</i> and <i>Cheylostigmaeus</i>). However, many other characteristics (e.g., both subcapitular setae <i>m</i> and <i>n</i> posterolaterad to pharynx; palpgenu with only 1 seta on the adult, terminal eupathidia on palptarsus mostly fused, coxa II with only 1 seta; endopodal shields around coxae III­IV absent, trochanter III with 1 seta) indicate that <i>Primagistemus</i> is much more closely related to the genera, <i>Agistemus</i>, <i>Zetzellia</i>, <i>Neilstigmaeus</i>, <i>Pilonychiopus</i> and <i>Parastigmaeus</i>. <i>Remarks</i>. Adult females of <i>Primagistemus</i> <b>gen. nov.</b> are distinguished from those of <i>Agistemus</i> by having 4 pairs of setae on the propodosomal shield, by lacking postocular bodies, by having 3 pairs of aggenital setae, and by having 2 setae on genu II. They are also distinguished from those of <i>Stigmaeus</i> by the terminal eupathidia on palptarsus being mostly fused and subterminally separated into 3 minute prongs, by both subcapitular setae posterolaterad of pharynx, by having only 1 seta on coxa II, and by lacking endopodal shields around coxae III­IV.
description: Published as part of <i>Fan, Qing-Hai &amp; Zhang, Zhi-Qiang, 2002, Primagistemus gen. nov. (Acari: Prostigmata: Stigmaeidae), pp. 1-8 in Zootaxa 29</i> on pages 2-3, DOI: 10.5281/zenodo.4619905
description: {"references": ["Wood, T. G. (1967) New Zealand mites of the family Stigmaeidae (Acari, Prostigmata). Transactions of the Royal Society of New Zealand, 9 (9), 93 - 139."]}