José G. Palacios-Vargas a, Erika Rivero-Sánchez a, Yan Gao b, Margarita Ojeda a, *
a Universidad Nacional Autónoma de México, Facultad de Ciencias, Departamento de Ecología y Recursos Naturales, Laboratorio de Ecología y Sistemática de Microartrópodos, Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510 Mexico City, Mexico
b China Shanghai Natural History Museum, Shanghai Science & Technology Museum, Shanhaiguan Road, Jing’an district, Shanghai 200041, China
*Corresponding author: margojeda@gmail.com (M. Ojeda)
Received: 21 November 2023; accepted: 12 April 2024
http://zoobank.org/urn:lsid:zoobank.org:pub:7688F4F2-2A36-42D5-83D8-657DDB3F3AE8
Abstract
As a result of 40 years of work and many projects on soil fauna and especially springtails, a collection of edaphic microarthropods has been established at the Facultad de Ciencias, UNAM, and has the name of “Colección de ácaros y colémbolos del Laboratorio de Ecología y Sistemática de Microartrópodos”. During the revision of material belonging to the subfamily Pseudachorutinae kept in the Collembola collection, we obtained 581 records of 28 species of Pseudachorutes, from 20 states and 62 localities from Mexico. Three are new records: P. ca. algidensis, P. ca. crassus, and P. reductus, and 5 new species from soil, litter and epiphytic plants in Mexico are described and illustrated herein: P.tabasquensis sp. nov., P. mexicanus sp. nov., P. chichinautzin sp. nov., P. tillandsiodes sp. nov., and P.veracruzensis sp. nov.
Keywords: Springtails; Records; Distribution; Taxonomy
© 2024 Universidad Nacional Autónoma de México, Instituto de Biología. Este es un artículo Open Access bajo la licencia CC BY-NC-ND
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
Cinco especies nuevas de Pseudachorutes (Collembola: Neanuridae) de México
Resumen
Como resultado del trabajo de más de 40 años y diversos proyectos sobre la fauna del suelo, especialmente colémbolos, se estableció en la Facultad de Ciencias, UNAM, una colección de microartrópodos edáficos, registrada con el nombre de “Colección de ácaros y colémbolos del Laboratorio de Ecología y Sistemática de Microartrópodos”. Durante la revisión del material depositado en ella, especialmente de la subfamilia Pseudachorutinae, se obtuvo información de 581 registros de 28 especies de Pseudachorutes distribuidos en 20 estados y 62 localidades del país. De éstas, 3 son nuevos registros (P. ca. algidensis, P. ca. crasus y P. reductus) y 5 son especies nuevas provenientes de suelo, hojarasca y plantas epífitas en México, que se describen e ilustran aquí: P.tabasquensis sp. nov., P. mexicanus sp. nov., P. chichinautzin sp. nov., P. tillandsiodes sp. nov. y P.veracruzensis sp. nov.
Palabras clave: Colémbolos; Registros; Distribución; Taxonomía
Introduction
The genus Pseudachorutes Tullberg, 1871 (Neanuridae: Pseudachorutinae) was based on the type species Pseudachorutes subcrassus Tullberg, 1871 characterized by: 1) ocelli 8+8; 2) postantennal organ in one circle or ellipse; 3) Ant. III and IV dorsally fused, Ant. IV generally with 6 sensilla and apical bulb, Ant. III organ with 2 microsensilla in a cuticular fold, 2 guard sensilla and one microsensillum; 4) bucal cone sharp, mandible with 2 or more teeth, maxilla styliform; 5) unguiculus absent; 6) furcula usually well developed, mucro present; 7) sixth abdominal segment always visible in dorsal view, anal spines absent (Christiansen & Bellinger, 1998; Fjellberg, 1998; Palacios-Vargas, 1990).
Currently there are 119 species of Pseudachorutes in the world (Bellinger et al., 2023), and for Mexico records of 20 species from 18 states are known (Arango-Galván et al., 2007; Cutz-Pool et al., 2003, 2007a, b, 2008; Palacios-Vargas, 1997, 2005; Palacios-Vargas & Castaño-Meneses, 2003; Palacios-Vargas et al., 2000, 2007; Vázquez, 1988; Vázquez & Palacios-Vargas, 1990, 2004). The genus is found in great abundance in many ecosystems and biotopes, including soil, litter, mosses, epiphytic plants and even the forest canopy.
During a recent project to study a collection of the subfamily Pseudachorutinae housed in the Collembola collection of the Laboratorio de Ecología y Sistemática de Microartrópodos (LESM), we found 5 new species of Pseudachorutes and their descriptions and illustrations are given herein.
Materials and methods
Examination of the material deposited in the LESM scientific collection “Colección de ácaros y colémbolos” (register number D.F.-ENT-229-09-09, issued by Subsecretaría de Gestión para la Protección Ambiental, Dirección de Vida Silvestre) was made to separate all the specimens of the genus Pseudachorutes.The specimens are permanently mounted in Hoyer’s medium slides. Measurements are presented as the range with means in parentheses and expressed in micrometers (µm). Drawings were made with the aid of a phase contrast microscope Carl Zeiss Standard 3 K7, equipped with a drawing tube. The full body scales correspond to 500 µm, and the rest of the structures to 100 µm.
Type specimens are deposited in the LESM. The chaetotaxy system follows that of Jordana et al. (1997). Abbreviations used in this paper are: Ant. = antennal segment (s), Abd. = abdominal segment (s), PAO = postantennal organ, sgd = dorsal guard sensillum, sgv = ventral guard sensillum, Th. = thoracic segment (s).
Descriptions
Class Collembola Lubbock, 1870
Order Poduromorpha Börner, 1913
Family Neanuridae Börner, 1901
Subfamily Pseudachorutinae Börner, 1906
Genus Pseudachorutes Tullberg, 1871
New records
Pseudachorutes ca. algidensis Carpenter, 1925. Mexico: Hidalgo: Mineral El Chico, 2,900 m asl, 1 specimen, ex Tillandsia violacea, 10-IX-1998, J.A. Monterrubio, col. Pseudachorutes ca. crassus da Gama, 1964. Mexico: Popocatépetl, 3,800 m asl, 1 specimen, ex litter, 29-I-1983, J.G. Palacios, col. Pseudachorutes reductus Thibaud & Massoud, 1983. Mexico: Veracruz: Estación de Biología Tropical, Los Tuxtlas, 8 specimens, 20-X-1997, J. Álvarez, col. Tamaulipas: Rancho El Cielo, 975 m asl, 1 specimen, ex soil, XI-1987, F. J. Villalobos, col.
Pseudachorutes tabasquensis sp. nov.
(Fig. 1 A-L, Table 1a-c)
http://zoobank.org/urn:lsid:zoobank.org:act:C3BDFC0D-8F06-41F2-83317E7904656BB5
Description. Body length (n = 7): 2,625 µm (range: 1,250-4,000 µm). Body color gray-violet, with dark eyes patches. Granulations are fine and homogenous. Body setae simple and smooth, but with 2 kinds of setae, long macrosetae (M 22-24 µm) and short microsetae (m 10-12 µm), the sensorial setae relatively long (54-56 µm) (Fig. 1 A, B).
Figure 1. A-L. Pseudachorutes tabasquensis sp. nov. A) Dorsal chaetotaxy from head to Th. III; B) dorsal chaetotaxy from Abd. III. to Abd. VI; C) Ant. III-IV right antenna, dorsal view; D) Ant. III-IV right antenna, ventral view; E) PAO and nearby eyes; F) mandible; G) maxilla; H) labium; I) femur, tibiotarsus, and unguis III; J) dens and mucron; K) female genital plate; L) male genital plate.
Table 1
Pseudachorutes tabasquensis sp. nov. a) Head chaetotaxy, b) dorsal chaetotaxy, c) main characters between P. orghidani, P. conicus, and P. tabasquensis sp. nov.
| 1a. | |||||||
| sd | d | oc | c | p | |||
| Number of setae | 5 | 4+1 | 3 | 1 | 4 | ||
| Setae absent | c1, c3, c4 | ||||||
| 1b. | |||||||
| a | m | p | Setae absent | ||||
| Th. I | – | 3 | – | m2 | |||
| Th. II | 4 | 2 | 5 | a5 | m5 | ||
| Th. III | 3 | 2 | 5 | a2, a5 | m5 | ||
| Abd. I-III | 4 | – | 5 | a2 | |||
| Abd. IV | 4 | – | 6 | ||||
| Abd. V | 4 | – | 4 | ||||
| Abd. VI | 2 | 2 | 2+1 | ||||
| 1c. | |||||||
| Characters | P. conicus | P. tabasquensis sp. nov. | P. orghidani | ||||
| Labium setae L | – | + | ? | ||||
| Ant. IV sensilla | 5 | 6 | 5 | ||||
| Ventral tube setae | 3+3 | 4+4 | ? | ||||
| Mandible teeth | 3 | 2 | 3 | ||||
| Ventral file on Ant. IV | – | 25-30 short setae | 25-30 cuniform | ||||
| Vesicles of PAO | 13-15 | 13-17 | 17 |
Antennae as long as head. Ant. I with 7 setae, Ant. II with 11 setae. Ant. III and IV dorsally fused. Ant. segments ratio I: II: III+IV as 1: 1; 1.8. Ant. III-organ with 2 small straight internal sensilla under a cuticular fold, 2 guard sensilla (sgv about 1.4 times as long as sgd) and 1 microsensillum close to ventral guard sensillum. Ant. IV with trilobed apical bulb, 6 cylindrical sensilla, seta “i”, and one subapical organite (Fig. 1C), ventral file with 25-30 short and strongly spine-like setae (Fig. 1D). PAO elliptical composed of 13-17 simple vesicles, 0.9 times smaller than the nearest eyes (Fig. 1E). 8+8 eyes, F, G are 0.7 times smaller than others. Buccal cone elongated. Mandible with 2 slender teeth (Fig. 1F). Maxilla styliform, with 2 blades, one has an apical tooth, another has 2 apical teeth (Fig. 1G). Labium with normal chaetotaxy of the genus from setae A to G and 4 lateral setae. Setae L spine-shape (Fig. 1H).
Dorsal chaetotaxy as in figure 1A-B, table 1a, b. Seta a0 on the head absent, unpaired seta d1 present, sometimes, one additional seta d3’ between the seta d3 present. Th. I with 3+3 setae, plus 1+1 lateral. Seta a2 present on Th. II, but absent from Th. III to Abd. V. Sensorial setae s on the body in position of p4 and m6 on the thoracic segments II and III, and p5 from Abd. I to IV and p2 on Abd. V. Sensorial formula of the body 022/11111. Sensorial setae 2 times as long as the macrosetae. The ratio of the largest Abd. V setae and inner unguis length is 1.0. Thoracic sterna without setae.
Legs setation from I to III is, tibiotarsi 19, 19, 18, without tenent hairs; Femora 10, 10, 11, one ventro-proximal seta is an acuminate tenent hair; trochanters with 5,5,5; coxae 3, 7, 7; subcoxae 2: 0, 2, 2; subcoxae 1: 1, 2, 2. Unguis wide with one inner tooth near 1/3 part from the basal, and a weakly subbasal lateral tooth. Ratio of tibiotarsus III and unguis about 1.6. Unguiculus absent (Fig. 1I).
Furcula is well developed. Dens dorsally with 6 setae, ventral with a smooth area. Mucro straight, 1.8 times shorter than dens, with granulations and 2 small lamellae (Fig. 1J). Tenaculum with 3+3 teeth. Ventral tube with 4+4 setae. Female genital plate with 3+3 pregenital setae, 6-14 circumgenital setae and 1+1 eugenital setae (Fig. 1K). Male genital plate with 3+3 pregenital setae, 25 circumgenital setae and 4+4 eugenital setae (Fig. 1L).
Taxonomic summary
Type material. Holotype: male mounted on a slide (FC-UNAM: LESM-AC: 23013). 5 paratypes females and 1 juvenile mounted on slides (FC-UNAM: LESM-AC: 23014-23019), same data as holotype.
Type locality. Mexico, Tabasco, Tapijulapa, outside cave “Las Sardinas”, ex litter, 14-III-2002, D.A. Estrada col.
Etymology. The name is locative for the state of Tabasco where the type locality is.
Remarks
Pseudachorutes tabasquensis sp. nov. shares with P. orghidani Massoud & Gruia, 1973 the presence of 1 internal and 1 lateral tooth on unguis. The new species also resembles P. conicus Lee & Kim, 1994 from Korea due to the presence of 2 types of body setae. They all share a similar number of PAO vesicles (Table 1c), dens with 6 setae and tenaculum with 3+3 teeth. Main differences between them are shown in Table 1c. Additionally, P. conicus has a very long and thin unguis, but in P. tabasquensis it is short and thick.
Pseudachorutes mexicanus sp. nov.
(Fig. 2A-K, Table 2a-b)
http://zoobank.org/urn:lsid:zoobank.org:act:96997B68-
7B09-4EC1-9563-2D3DF01AEA77
Description. Body length (n = 17): 814 µm (range: 470-1,350 µm). Color of the body gray-violet, with a dark eyes patch. Granulations are fine and homogenous. Posterior setae of body long and capitated (Fig. 2A).
Antennae as long as head. Ant. I with 7 setae, Ant. II with 11 setae. Ant. III and IV dorsally fused. Ant. segments ratio I: II; III+IV as 1: 1.4; 3.2. Ant. III-organ with 2 small straight internal sensilla under a cuticular fold, 2 guard sensilla (sgv about 1.2 times as long as sgd) and 1 microsensillum close to ventral guard sensillum. Ant. IV with simple apical bulb, 6 cylindrical sensilla, seta “i”, 1 microsensillum and 1 subapical organite (Fig. 2B), ventral file poorly developed, with 20-35 short setae (Fig. 2C). PAO elliptical composed of 5-6 simple vesicles, 1.1 times as long as the nearest ocelli (Fig. 2D). 8+8 small ocelli, F, G are 0.9 times smaller than others. Buccal cone short. Mandible with 2 slender teeth (Fig. 2E). Maxilla with 2 blades, each has 2 apical teeth (Fig. 2F). Labium with normal chaetotaxy of the genus from setae A to G and 4 lateral setae, setae L spine-shape (Fig. 2G).
Dorsal chaetotaxy as in figure 2A, table 2b. Seta a0 on head absent, unpaired seta d1 present. Th. I with 3+3 setae. Setae a2 present on Th. II, but absent from Th. III to Abd. V. Sensory setae s on the body in position of p4 and m6 on Th. II and III, and p5 from Abd. I to IV and p2 on Abd. V. Sensorial formula of the body 022/11111. Sensory setae longer than 1.1-1.5 times as long as body setae. Ratio of largest Abd. V setae and inner unguis length is 1.4. Thoracic sterna without setae. Ventral tube with 4+4 setae. Female genital plate with 2+2 pregenital setae, 4-9 circumgenital setae and 1+1 eugenital setae (Fig. 2H). Male genital plate with 3+3 pregenital setae, 10 circumgenital setae and 4+4 eugenital setae (Fig. 2I).
Tibiotarsi I, II, III with 18, 18, 17 setae respectively, with 1 tenent hair long and capitate (Fig. B8). Femora I, II, III with 9, 9, 10 setae respectively. Trochanters with 5 setae each. Coxae I, II, III with 3, 7, 7 setae respectively. Subcoxae 2 I, II, III with 0, 2, 2 setae respectively. Subcoxae 1. I, II, III with 1, 2-3, 2-3 setae respectively. Unguis wide with 1 weakly apical inner tooth. Ratio of tibiotarsus III and unguis about 1.0. Unguiculus absent (Fig. 2J).
Furcula well developed. Dens dorsally with 5 setae. Mucro straight, 3 times shorter than dens, with two larger bladder-like swelling visible and a hook-like end (Fig. 2K). Tenaculum with 3+3 teeth.
Figure 2. A-K. Pseudachorutes mexicanus sp. nov. A) Dorsal chaetotaxy from head to abdomen VI; B) Ant. III-IV right antenna, dorsal view; C) Ant. III-IV right antenna, ventral view; D) PAO and nearby eye; E) mandible; F) maxilla; G) labium; H) female genital plate; I) male genital plate; J) femur, tibiotarsus, and unguis III; K) furcula and tenaculum.
Taxonomic summary
Type material. Holotype: female mounted on a slide (FC-UNAM: LESM-AC: 22996). 16 paratypes: 4 females, 1 male and 11 juveniles under slides (FC-UNAM: LESM-AC: 22997-23012), same data as holotype.
Type locality. Mexico, Hidalgo, Mineral El Chico, 10-IX-98, J.A. Monterrubio, col. Ex Tillandsia violacea.
Etymology. The name of the new species is after the country of the type locality: Mexico.
Remarks
This species resembles P. americanus Stach, 1949 with a similar number of vesicles in PAO (P. americanus with 5-8 vesicles), unguis with 1 minute tooth near apex, one large, clavate tenent hair, ventral tube with 4+4 setae, tenaculum with 3+3 teeth and posterior abdominal setae clearly capitate. However, dens of the new species with 5 setae, maxilla with 2 blades and each has 2 apical teeth, 6 cylindrical sensilla on Ant. IV and a poorly developed ventral file with 20-35 short setae is different from P. americanus.
Pseudachorutes chichinautzin sp. nov.
(Fig. 3A-J, Table 3a-c)
http://zoobank.org/urn:lsid:zoobank.org:act:1098FF48-F5CE-4D51-8F9E-0EB9E217AA40
Description.Body length (n = 8): 1,904 µm (range: 850-2,010 µm). Color of the body gray-violet, with a dark eyes patch. Granulations homogenous. Lateral and posterior body setae are longer and truncate (Fig. 3A).
Table 2
Pseudachorutes mexicanus sp. nov. a) Head chaetotaxy, b) dorsal chaetotaxy.
| 2a. | ||||||
| sd | d | oc | c | p | ||
| Number of setae | 5 | 4+1 | 3 | 4 | 4 | |
| 2b. | ||||||
| a | m | p | Setae absent | |||
| Th. I | – | 3 | – | m2 | ||
| Th. II | 4 | 3 | 5 | a4 | ||
| Th. III | 3 | 3 | 5 | |||
| Abd. I-III | 3 | 2 | 5 | |||
| Abd. IV | 4 | – | 5 | |||
| Abd. V | 3 | – | 4 | |||
| Abd. VI | 2 | 2 | 2+1 |
Antennae as long as head. Ant. I with 7 setae, Ant. II with 12 setae. Ant. III and IV dorsally fused. Ant. segments ratio I: II; III+IV as 1: 1.2: 2.0. Ant. III-organ with 2 small internal sensilla under a cuticular fold, 2 guard sensilla (sgv about 1.1 times as long as sgd) and 1 microsensillum close to ventral guard sensillum. Ant. IV with trilobed apical bulb, 6 cylindrical sensilla, seta “i”, and one subapical organite (Fig. 3B), ventral file with about 10 strong, spine-like setae and several slender, normal setae (Fig. 3C). Some setae on Ant. IV are blunt. PAO elliptical composed of 10-12 vesicles, sometimes, 1 or 2 of them inside in the others, subequal to nearest eyes (Fig. 3D). 8+8 eyes, F, G are 0.7 times smaller than others. Buccal cone elongated. Mandible is not clearly detected, about 2 or 3 slender teeth. Maxilla with 2 blades and one has an apical tooth, and the other styliform (Fig. 3E). Labium with normal chaetotaxy of the genus from setae A to G and 5 lateral setae, setae L spine-shape (Fig. 3F).
Dorsal chaetotaxy as in Fig. 3A, table 3a, b. Seta a0 on the head absent, unpaired seta d1 present. Th. I with 3+3 setae, plus 1+1 lateral. Setae a2 present on Th. II, but absent from Th. III to Abd. V. Sensorial setae s on the body in position of p4 and m6 on the thoracic segments II and III, and p5 from Abd. I to IV and p3 on Abd. V. Sensorial formula of the body 022/11111. Sensorial setae 1.2-1.7 times as long as the normal setae. The lateral setae of the body longer and blunt. Ratio of largest Abd. V setae and inner unguis length is 1.0. Thoracic sterna without setae. Ventral tube with 4+4 setae. Female genital plate with 3+3 pregenital setae, 9 circumgenital setae and 1+1 eugenital setae (Fig. 3G). Male genital plate with 3+3 pregenital setae, 8 circumgenital setae and 4+4 eugenital setae (Fig. 3H).
Leg setation from I to III, is tibiotarsi 19, 19, 18, with 1 acuminate tenent hair a little longer than others; femora 9, 9,10, one ventro-proximal seta is an acuminate tenent hair; trochanters with 5,5,5; coxae 3, 7, 7; subcoxae 2: 0, 2, 2; subcoxae 1: 1, 2, 2. Unguis wide, with one inner tooth near 1/3 part from the basal. Sometimes, a pair of weakly subbasal lateral tooth is present. Ratio of tibiotarsus III and unguis about 1.6. Unguiculus absent (Fig. 3I).
Figure 3. A-J. Pseudachorutes chichinautzin sp. nov. A) Dorsal chaetotaxy; B) Ant. III-IV right antenna, dorsal view; C) Ant. III-IV right antenna, ventral view; D) PAO, eye patch and ocular setae; E) maxilla; F) labium; G) female genital plate; H) male genital plate; I) femur, tibiotarsus, and unguis III; J) furcula and tenaculum.
Furcula well developed. Dens dorsally with 6 setae, ventral with fine granulate. Mucro straight, 1.7 times shorter than dens, with 2 big lamella and a clearly hook-like end. Tenaculum with 3+3 teeth (Fig. 3J).
Taxonomic summary
Material examined. Holotype: female under slide (FC-UNAM: LESM-AC: 22974). 7 paratypes: 4 females, 2 males and 1 juvenile under slides, same data as holotype (FC-UNAM: LESM-AC: 22975-22981).
Type locality. Mexico; Morelos, Derrame Chichinautzin. 12-IX-1976. J. Palacios, col. Ex. Tillandsia prodigiosa.
Etymology. The name is that of the Chichinautzin lava flow (state of Morelos), as a noun of type locality.
Remarks
Pseudachorutes chichinautzin sp. nov. shares with P. orghidani and P. subcrassus Tullberg, 1871 the presence of 1 internal and 1 pair of lateral teeth on unguis. The new species also resembles P. tabasquensis sp. nov. with 2 types of body setae, Ant. IV with 6 sensilla, trilobed apical bulb. Dens with 6 setae and tenaculum with 3+3 teeth. Main differences between them can be seen in table 3c.
Table 3
Pseudachorutes chichinautzin sp. nov. a) Head chaetotaxy, b) dorsal chaetotaxy, c) main characters between P. orghidani, P. subcrassus, P. chichinautzin sp. nov. and P. tabasquensis sp. nov.
| 3a. | ||||||
| sd | d | oc | c | p | ||
| Number of setae | 5 | 4+1 | 3 | 2 | 4 | |
| Setae absent | c1, c4 | |||||
| 3b. | ||||||
| a | m | p | Setae absent | |||
| Th. I | – | 3 | – | m2 | ||
| Th. II | 4 | 2 | 5 | a5 | m4 | |
| Th. III | 3 | 2 | 5 | a2, a5 | m4 | |
| Abd. I-III | 3 | – | 5 | a2, a5 | ||
| Abd. IV | 3 | – | 5 | a2, a3, a5 | ||
| Abd. V | 3 | – | 3 | a2 | P2 | |
| Abd. VI | 2 | 2 | 2+1 | |||
| 3c. | ||||||
| Characters | P. subcrassus | P. chichinautzin sp. nov. | P. tabasquensis sp. nov. | P. orghidani | ||
| Ant. IV sensilla | 5-6 | 6 | 6 | 5 | ||
| Mandible teeth | 4 | 2-3 | 2 | 3 | ||
| Ventral file on Ant. IV | 20 | 10 strong setae | 25-30 short setae | 25-30 cuniform | ||
| Vesicles of PAO | 8-10 | 10-12 | 13-17 | 17 | ||
| Lateral blunt setae | – | + | – | + |
Pseudachorutes tillandsiodes sp. nov.
(Fig. 4A-K, Table 4a-c)
http://zoobank.org/urn:lsid:zoobank.org:act:9FFB9169-78E7-4BA3-8C9A-8F3EBEA4DD10
Description. Body length (n = 6): 2,260 µm (range: 1,750-2,860 µm). Color of the body violet, with a white strip from Th. I to Th. II and a dark eyes patch. Granulations fine and homogenous. Body with simple and spine-like setae, p row longer on last abdominal segments (24-40 µm), long sensorial setae (75-100 µm) (Fig. 4A, B).
Antennae shorter than head, 155 µm and 180 µm respectively. Ant. I with 7 setae Ant. II with 12 setae. Ant. III and IV dorsally fused. Ant. segments ratio I: II; III+IV as 1: 1; 1.9. Ant. III-organ with 2 small curving sensilla under a cuticular fold, 2 guard sensilla (sgv is about 1.4 times as long as sgd) and 1 microsensillum close to ventral guard sensillum. Ant. IV with trilobed apical bulb, 6 thin and cylindrical sensilla, seta “i”, one microsensillum and one subapical organite (Fig. 4C), ventral side with about 20 setae with some thick and spine-like (Fig. 4D). PAO elliptical composed of 14 vesicles, 1.2 times as long as the nearest eyes. 8+8 eyes, F, G 0.9 times as big as others (Fig. 4E). Buccal cone elongated. Mandible has 2 big teeth, the apical with clearly 3 small teeth (Fig. 4F). Maxilla with 2 blades, one with 2 apical teeth (Fig. 4G). Labium with normal chaetotaxy of the genus from setae A to G and 4 lateral setae, setae L reduced to a minus spine, difficult to see (Fig. 4H).
Dorsal chaetotaxy as in figure 4A, B, table 4a, b. Seta a0 on head absent, unpaired seta d1 present. Th. I with 3+3 setae. Setae a2 present on Th. II, but absent from Th. III to Abd. V. m5 present on Th. II to Th. III. Sensorial setae on body in position of p4 and m6 on thoracic segments II and III, p5 from Abd. I to IV and p2 on Abd. V. Sensorial formula of the body 022/11111. Sensorial setae 2.5-4.0 times as long as the normal setae. Ratio of largest Abd. V setae and inner unguis length is 0.6. Thoracic sterna without setae. Ventral tube with 4+4 setae. Female genital plate with 3+3 pregenital setae, 9 circumgenital setae and 1+1 eugenital setae (Fig. 4I). No males were found.
Figure 4. A-K. Pseudachorutes tillandsiodes sp. nov. A) Dorsal chaetotaxy from head to Th. III; B) dorsal chaetotaxy from Abd. III. to Abd. VI; C) Ant. III-IV right antenna, dorsal view; D) Ant. III-IV right antenna, ventral view; E) PAO, eye patch and ocular setae; F) mandible; G) maxilla; H) labium; I) female genital plate; J) femur, tibiotarsus, and unguis III; K) dens and mucron.
Leg setation from I to III, is tibiotarsi 19, 19, 18, no tenent hair; femora 9, 10, 10, one ventro-proximal seta is an acuminate tenent hair; trochanters with 5,5,5; coxae 3, 7, 8; subcoxae 2: 0, 2, 2; subcoxae 1: 1, 2, 2. Unguis with one clearly inner tooth at the basal side. Ratio of tibiotarsus III and unguis about 1.5. Unguiculus absent (Fig. 4J).
Furcula well developed. Dens dorsally with 6 setae, ventral with fine granulations. Mucro straight, 2.2 times shorter than dens, with 2 thin but long lamella, without hook-like end (Fig. 4K). Tenaculum with 3+3 teeth.
Table 4
Pseudachorutes tillandsiodes sp. nov. a) Head chaetotaxy, b) dorsal chaetotaxy, c) main characters between P. gilvusi, and P. tillandsiodes sp. nov.
| 4a. | ||||||
| sd | d | oc | c | p | ||
| Number of setae | 5 | 4+1 | 3 | 4 | 4 | |
| 4b. | ||||||
| a | m | p | Setae absent | |||
| Th. I | – | 3 | – | m2 | ||
| Th. II | 5 | 2 | 5 | m4 | ||
| Th. III | 4 | 2 | 5 | a2 | m4 | |
| Abd. I-III | 4 | – | 5 | a2 | ||
| Abd. IV | 4 | – | 5 | a2 | ||
| Abd. V | 4 | – | 3 | P4 | ||
| Abd. VI | 2 | 2 | 2+1 | |||
| 4c. | ||||||
| Characters | P. gilvus | P. tillandsiodes sp. nov. | ||||
| Setae d1 on head | 1+1 | 1 | ||||
| Setae number on Th. I | 2+2 | 3+3 | ||||
| Setae a2 on Th. II | – | + | ||||
| Ant. IV sensilla | 7 | 6 | ||||
| Ventral tuve setae | 3+3 | 4+4 |
Taxonomic summary
Material examined. Holotype: female under slide (FC-UNAM: LESM-AC: 23172). 5 Paratypes: 4 female and 1 juvenile (FC-UNAM: LESM-AC: 23173-23177).
Type locality. Mexico; Hidalgo, Mineral El Chico. 10-IX-98. J. A. Monterrubio, col. Ex Tillandsia violacea.
Etymology. The name is taken from the epiphytic genus Tillandsia (Bromeliacea) habitat where the species was found.
Remarks
Pseudachorutes tillandsiodes sp. nov. resembles P. gilvus Oliveira & Deharveng, 1995 with white strips and long sensilla on the body, similar number of postantennal organ vesicles (P. gilvus with 11-15 vesicles), unguis with 1 inner tooth, tibiotarsi I-III with 19, 19, 18 setae and dens with 6 setae. The main differences between them are shown in table 4c. However, P. gilvus has 3 white stripes on the body: the first on the posterior part of head and the middle of Th. I, the second on the mesothorax and the third on Abd. I-II; P. tillandsiodes sp. nov. only with 1 white stripe from Th. I to Th. II.
Pseudachorutes veracruzensis sp. nov.
(Fig. 5A-L, Table 5a, b)
http://zoobank.org/urn:lsid:zoobank.org:act:2C15B37C-080B-4DF9-AD8E-9AE899AEA907
Material examined. Holotype: female under slide (FC-UNAM: LESM-AC: 2133a). 10 paratypes: 7 females and 3 males under slides, same data as holotype (FC-UNAM: LESM-AC: 2131a-2132c, 2132a-2132e, 2133b, 2133c)
Type locality. Mexico; Veracruz, Xalapa, La Herradura. 26-IX-26-10/1998, ex Bosque Mesófilo de Montaña, J. Márquez, col.
Description. Body length (n = 11): 1,900 (range: 1,050-3,400 µm). Color body violet, with a dark eyes patch. Granulations fine and homogenous. Body with short and simple setae (10-12), some of them longer in abdomen segments, especially on 4th segment (22-26 µm), long sensorial setae (67-75 µm) (Fig. 5A).
Antennae little shorter than head, 100 µm and 105 µm, respectively. Ant. I with 7 setae, Ant. II with 12 setae. Ant. III and IV dorsally fused. Ant. segments ratio I: II; III+IV as 1: 1; 2. Ant. III-organ with 2 small straight sensilla under a cuticular fold, 2 guard sensilla (the sgv is about 1.1 times as long as sgd) and 1 microsensillum close to ventral guard sensillum. Ant. IV dorsally with trilobed apical bulb, 6 thin and cylindrical sensilla, seta “i”, 1 microsensillum and 1 subapical organite (Fig. 5B), ventral side has a distinct ventral file with about 40 short setae (Fig. 5C). PAO elliptical composed of 17-20 vesicles, 1.5 times as long as the nearest eyes. 8+8 eyes, F, G 0.8 times as big as others (Fig. 5D). Buccal cone elongated. Mandible has 2-3 big teeth (Fig. 5E). Maxilla with 1 blade and 2 apical teeth (Fig. 5F). Labium with normal chaetotaxy of the genus from setae A to G and 3 lateral setae, one longer spine-like setae present at the place of setae L (Fig. 5G).
Dorsal chaetotaxy as in figure 5A and table 5a,b. Seta a0 on head absent, unpaired seta d1 present. Th. I with 3+3 setae. Setae a2 present on Th. II, but absent from Th. III to Abd. IV. m5 present on Th. II to Th. III. Sensorial setae s on the body in position of p4 and m6 on Th. II and III, p5 from Abd. I to IV and p2 on Abd. V. Sensorial formula of the body 022/11111. Sensorial setae 6.5-7.0 times as long as the shorter setae. The ratio of the largest Abd. V setae and inner unguis length is 0.5. Thoracic sterna without setae. Ventral tube with 4+4 setae. Female genital plate with 3+3 pregenital setae, 7 circumgenital setae and 1+1 eugenital setae (Fig. 5H). Male genital plate with 2+2 pregenital setae, 16 circumgenital setae and 4+4 eugenital setae (Fig. 5I).
Leg setation from I to III, is tibiotarsi 19, 19, 18, no tenent hairs; femora 13, 11, 10, one ventro-proximal seta is an acuminate tenent hair; trochanters with 6,6,5; coxae 3, 7, 8; subcoxae 2: 0, 2, 2; subcoxae 1: 1, 2, 2. Unguis with 1 big and 1 small inner tooth together with 2 pairs of lateral teeth (Fig. 5J). Ratio of tibiotarsus III and unguis about 1.4. Unguiculus absent (Fig. 5K).
Furcula well developed. Dens dorsally with 6 setae, ventral granulate. Mucron granulated with broad and long lamella, 1 slightly hook-like end, 2.0 times shorter than dens (Fig. 5L). Tenaculum with 3+3 teeth.
Etymology. The name is a locative for the State of Veracruz where the type locality is found.
Remarks
Pseudachorutes veracruzensis sp. nov. resembles P. orghidani with granules on mucron and dens with 6 setae, mandible with 3 teeth, unguis with lateral teeth, similar number of PAO (P. orghidani with 17 vesicles) and ventral file on Ant. IV. The main difference between the species is the shape of short setae in the ventral file (P. orghidani has small setae with apex truncate) and number of sensilla on Ant. IV (P. orghidani with 5) and the teeth on unguis (P. orghidani only with 1+1 lateral teeth).
Discussion
After revision and analysis of the material deposited in the LESM collection, we were able to update the knowledge of genus Pseudachorutes in Mexico, describing 5 new species: P. tabasquensis sp. nov., P. veracrucensis sp. nov., P. tillandsiodes sp. nov., P. chichinautzin sp. nov., and P. mexicanus sp. nov. Three new records for the country are added, for the following species: P. ca. algidensis from Hidalgo, P. ca. crassus from Estado de México, these must be confirmed with the collection of more specimens that will allow the species to be fully determined. For now, this information is presented as an element to show the richness of species of the genus in the country. Pseudachorutes reductus has a distribution in the Antilles and southern Florida, the new records in Mexico extend its distribution area and confirm the affinity of the species to the Atlantic area. Total records for Pseudachorutes is increased to 28 species, from 20 states and 62 localities within the country. Quintana Roo and Hidalgo were the states with the highest number of species present (11 and 10, respectively), followed by Morelos, Estado de México, Puebla, Veracruz, and Guerrero (8, 7, 6, 6, and 4 species recorded in each one), 6 states have 3 species, 5 have 2 and Querétaro and San Luis Potosí only have 1 species recorded. Three species are widely distributed in Mexico: P. corticolus, P. simplex, and P. subcrassoides. Diversity of the genus in Mexico is around 21% of the total known worldwide, and therefore the country becomes one with the greatest number of species present.
Figure 5. A-L. Pseudachorutes veracruzensis sp. nov. A) Dorsal chaetotaxy; B) Ant. III-IV right antenna, dorsal view; C) Ant. III-IV right antenna, ventral view; D) PAO, eye patch and ocular setae; E) mandible; F) maxilla; G) labium; H) female genital plate; I) male genital plate; J) femur, tibiotarsus, and unguis III; K) unguis III, ventral view; L) dens and mucron.
Regarding biotopes where the species preferably live, we found that litter, epiphytic plants, soil, mosses and decaying wood are the most suitable habitats for this springtail. However, sand, canopy, wood, caves and anthills are also microhabitats used by some species.
Table 5
Pseudachorutes veracruzensis sp. nov. a) Head chaetotaxy, b) dorsal chaetotaxy.
| 5a. | |||||
| sd | d | oc | c | p | |
| Number of setae | 5 | 4+1 | 3 | 2 | 4 |
| Setae absent | c1, c3 c4 | ||||
| 5b. | |||||
| a | m | p | Setae absent | ||
| Th. I | – | 3 | – | m2 | |
| Th. II | 4 | 2 | 5 | a5 | m4 |
| Th. III | 3 | 2 | 5 | a2, a5 | m4 |
| Abd. I-III | 3 | – | 5 | a2, a5 | |
| Abd. IV | 4 | – | 5 | a2, a3 | |
| Abd. V | 3 | – | 4 | a4 | |
| Abd. VI | 3 | 2 | 2+1 |
The analysis and revision of the morphology of the 5 species described, allowed us to come to the following conclusions about the morphology of the genus that needs to be taken in consideration. Size of body setae should be a characteristic to be taken into consideration for the description of the species, since we observed that it is a variable character. Antennae are a uniform structure and characters associated with the sensory organ of Ant. III have little relevance at a specific level. Sensory file of Ant. IV, present a varied shape and number, from 8 to 40 setae. Apical vesicle of Ant. lV is trilobed in most species and others have a simple shape. Number of ocelli is stable within the genus, presenting 8+8. The maxillae and mandibles vary in all species. Maxillae can be needle-shaped, crocheted or styliform, they may or may not be lamellar and the number of lamellae is variable, and in most cases, there are 1 to 2 apical teeth. The number of teeth in the mandibles in almost all species ranges from 1 to 5. The number of teeth in the retinaculum is a constant character among the species of the genus, with 3+3 teeth. The ventral tube in almost all species has 4+4 setae. The number of setae in the dens varies from three to seven, but most have six setae. The mucron has 2 lamellae in all species, except in P. reductus, where it is greatly reduced. The shape of the mucron is variable, from elliptical, triangular, elongated, short, curved, widened, or with a bladder-shaped base.
Acknowledgments
This study had the support from the International Relationships of Universidad Nacional Autónoma de México issued to the first author and partially by the National Natural Sciences Foundation of China (No. 3217047 and 32370491). Blanca E. Mejía Recamier helped remount specimens. Kenneth A. Christiansen gave criticism, suggestions, and literature. We thank Erick García and Eduardo Pacheco who assigned the catalogue numbers for the slides. Daniel A. Estrada, Jesús A. Monterrubio, Juan Márquez donated the specimens.
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