Scapheremaeus Berlese 1910
Creators: name: Palacios-Vargas, José G.
name: Jaimes Murillo, Kevin A.
name: Ojeda, Margarita
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Cymbaeremaeidae
Scapheremaeus

description: Key for all known species of Scapheremaeus from Mexico (modified from Palacios-Vargas et al. 2022)
1. Notogaster without a centrodorsal region; total body length more than two times its width; notogaster rectangular, with a transverse line separating the lenticule... Scapheremaeus alvarezius Ríos and Palacios-Vargas, 1998 (Veracruz: Los Tuxtlas).
- Notogaster with a well-defined centrodorsal region; sensillum (ss) variously shaped................................ 2
2. Notogaster pyriform, almost round, with only seven pairs of setae and strongly contrasting microsculpture between the centrodorsal region and the circumgastric scissure, tridactylous, genitoanal chaetotaxy 4-1-1-2.............................................................. Scapheremaeus colloffi Palacios-Vargas et al. 2022 (Veracruz: Los Tuxtlas).
- Notogaster usually elongate with eight or more pairs of setae, genitoanal chaetotaxy distinct......................... 3
3. Eight pairs of notogastral setae, genitoanal chaetotaxy 6-1-2-3; humeral process very long, pointed and strongly curved............................ Scapheremaeus palaciosi Ríos, 1996 (CDMX: Contreras; Edo. de Mex.: Popocatépetl volcano).
- Notogaster with nine or more pairs of setae................................................................ 4
4. Notogaster with nine pairs of setae, genitoanal chaetotaxy 6-1-2-2, round lenticule.................................................................... Scapheremaeus dirzoius Palacios-Vargas and Páez, 2018 (Veracruz: Los Tuxtlas).
- Notogaster with ten to 13 pairs of setae, distinct genito-anal chaetotaxy.......................................... 5
5. Notogaster irregular with 14 pairs of setae, bidactylous, humeral process pointed........................................ Scapheremaeus baloghius Ríos and Palacios-Vargas, 1998 (Jalisco: Chamela; Chiapas: Chajul; Veracruz: Los Tuxtlas).
- Notogaster with ten pairs of setae........................................................................ 6
6. Epimeral chaetotaxy 3-1-3-3, bidactylous, triangular humeral process present; three pairs of setae in the centrodorsal region........................................ Scapheremaeus schatzi Ríos and Palacios-Vargas, 1998 (Jalisco, Chamela).
- Epimeral chaetotaxy 3-1-2-2............................................................................ 7
7. Notogaster with a well-developed diagonal extensions of centrodorsal region; setae of the centrodorsal region spiniform, c2, la, hi-3 and p1-p3 bacilliform shape; sensillum (Bothridial seta) with a striate capitulum........................................................................................ Scapheremaeus subiasi sp. nov. (El Zapote, Morelos).
- Notogaster without diagonal extensions; total body length less than two times its width............................. 8
8. Centrodorsal region of notogaster with a longitudinal ridge.................................................... 9
- Centrodorsal region of notogaster without a longitudinal ridge................................................ 11
9. Notogaster setae rod-shape with normal alveoli............................................................ 10
- Notogaster setae flame-shaped with relatively large alveoli, lichen-shaped sensillum (Bothridial seta), three longitudinal carinae.... Scapheremaeus flamiferus Palacios-Vargas and Ríos, 1998 (Nicaragua: León; Mex: Q. Roo, Guerrero, Veracruz).
10. Sensillum (Bothridial seta) black, barbed and elongated, an incomplete crest between the lenticule and the centrodorsal plate.................. Scapheremaeus grahamius Ríos and Palacios-Vargas, 1998 (CDMX: Reserva Pedregal de San Ángel).
- Sensillum (Bothridial seta) moruliform and elliptical. A lateral and posterior crest to the lenticule that borders the central area present. Posterior margin of the notogaster truncated and a well-developed concavity........................................................... Scapheremaeus tillandsiophilus Ríos and Palacios-Vargas, 1998 (Morelos: Chichinautzin).
11. Centrodorsal region of notogaster with two lateral ridges joining the lm and lp setae; anterior region of notogaster semi rectangular. Rostral setae minute (3 μm).................................................................................................. Scapheremaeus eugenius Ríos y Palacios-Vargas, 1998 (Jalisco: Sierra de Manantlán).
- No lateral ridges and average rostral setae about 10 μm or more............................................... 12
12. Notogaster with ridges between lenticule and central zone................................................... 16
- Notogaster without ridges between the lenticule and the central zone........................................... 13
13. Centrodorsal region of the notogaster almost circular. Prodorsum with very long lamellae, inhabitant rock surfaces........................................................ Scapheremaeus chaac Ríos and Palacios-Vargas, 1998 (Yucatán).
- Centrodorsal region of notogaster elliptic. Prodorsum without lamellae.......................................... 14
14. All setae of notogaster and ad1 and ad2 fungiform, humeral processes spiniform...................................................................... Scapheremaeus fungisetosus Ríos and Palacios-Vargas, 1998 (Jalisco: Chamela).
- Centrodorsal region of the notogaster with or without longitudinal crest, setae no fungiform......................... 15
15. Humeral processes absent. Lamellar setae setiform, lichen-shaped sensillum (Bothridial seta), with a small notch near seta c2 .................................. Scapheremaeus mahunkaius Ríos and Palacios-Vargas, 1998 (Jalisco, Chamela).
- Humeral process present. Lamellar setae bacilliform, sensillum (bothridial seta) head black; no notch near setae c2 .......................................... Scapheremaeus simplex Ríos and Palacios-Vargas, 1998 (Morelos: Chichinautzin).
16. Body very flattened (body length/thickness = 3.4). Lamellar and notogastral setae minute (4μm)........................................................... Scapheremaeus nogueraius Ríos and Palacios-Vargas, 1998 (Jalisco: Chamela).
- Body normal, not flattened (length/thickness = 1.6–2.3). Lamellar setae medium to long........................... 17
17. Sensillum (Bothridial seta) lichen-shaped. Notogaster broad (length/width ratio = 1.5), capitulum sensilla hyaline................................ Scapheremaeus volcanicus Ríos and Palacios-Vargas, 1998 (Edo. de Mex.: volcán Popocatépetl)
- Sensillum (Bothridial seta) has a different shape. Notogaster not as wide........................................ 18
18 Sensilum (Bothridial seta) with a morula-like appearance, body relatively elongated (length/width = 1.8). Humeral process absent......................... Scapheremaeus morulisensillatus Ríos and Palacios-Vargas, 1998 (CDMX: Contreras)
- Sensilla not morula-shaped............................................................................. 19
19 Notogastral setae rod-shaped, long (15 μm).Posterior margin of notogaster with irregular edges. Posterior margin of circumdorsal region strongly projected and triangular........................................................ Scapheremaeus magdalenae Ríos and Palacios-Vargas, 1998 (Baja California: Cedros Island, Baja California Sur: Sierra La Laguna).
- Body setae not rod-shaped, distinct, shorter. Posterior margin of notogaster rounded............................... 20
20 Prodorsum with short lamellar cusps, translamella incomplete. Cerotegument strongly developed. Notogaster with two circular central areas. Posterior notogastral setae fungiform............................................................ Scapheremaeus tonatiuh Palacios-Vargas, Rìos and Vázquez, 1998 (Jalisco: Chamela, Q. Roo: Sian Ka’an; Chiapas: Chajul).
- Prodorsum without lamellar cusps and without translamella. Cerotegument inconspicuous. Notogaster with a single central area, with tiny setae slightly clavate and large alveolus..................................................................................... Scapheremaeus hectorperezius Ríos and Palacios-Vargas, 1998 (Veracruz, Los Tuxtlas).
description: Published as part of Palacios-Vargas, José G., Jaimes Murillo, Kevin A. & Ojeda, Margarita, 2024, New species of Scapheremaeus (Acari: Oribatida: Cymbaeremaeidae) from an epiphytic environment in Morelos, Mexico, pp. 97-105 in Zootaxa 5556 (1) on pages 103-104, DOI: 10.11646/zootaxa.5556.1.9, http://zenodo.org/record/14595399