A new species of Aethiopella (Collembola: Neanuridae) from Nicaragua

Una nueva especie de Aethiopella (Collembola: Neanuridae) de Nicaragua

José G. Palacios-Vargas^* and Maira Montejo-Cruz

Laboratorio de Ecología y Sistemática de Microartrópodos, Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México. Circuito exterior s/n, Cd. Universitaria, 04510 México D. F., Mexico. * jgpv@ciencias.unam.mx

Recibido: 05 mayo 2014
Aceptado: 19 julio 2014

Abstract

Aethiopella pilarandresae sp. nov. is described and illustrated. It is characterized by its small size, 6 mandibular teeth, small mucro and postantennal organ with 20-27 vesicles. It is compared with the other species from America and a key for the world species is included.

Key words: taxonomy, Pseudachorutinae, Aethiopella, Estelí.

Resumen

Se describe e ilustra Aethiopella pilarandresae sp. nov. Se caracteriza por su talla pequeña, 6 dientes mandibulares, mucrón pequeño y órgano postantenal con 20-27 vesículas. Se compara con las otras especies de América y se proporciona una clave para las especies del mundo.

Introduction

Originally members of this genus were considered part of Ceratrimeria. Börner 1906. Handschin (1942) revised the genus and divided it into 2 new genera, Aethiopella and Neotropiella, both characterized by a well-developed furcula and the presence of a moruliform postantennal organ. The main difference between them is the number of eyes per side: 8 in Aethiopella and 5-7 in Neotropiella (Handschin, 1942). Aethiopella Handschin, 1942 comprises up to date 22 named species, most of which are distributed in Africa and a few in the Pacific islands. From America, only 4 species have been described: A. ariana Najt, Thibaud and Weiner, 1990, A. caraibensis Thibaud and Massoud, 1983, A. delamarei Arlé, 1960, and A. littoralis Fernandes and Mendonça, 2003 for the Neotropical region (Bellinger et al., 1996-2014).

In this contribution, we describe a new species collected in Estelí, Nicaragua and provide a key for the identification of known species. Abbreviations used in this description are: Ant.= antennal segment; Abd.= abdominal segment; PAO= postantennal organ; sgd= dorsal guard sensillum; sgv= ventral guard sensillum; Th.= thoraxic segment.

Materials and methods

Specimens were collected in Mesas de Moropotente (Estelí), Nicaragua at 3 field plots representative of recently abandoned paddocks, in 3 year old scrublands and in mature "carbonales" (name given to patches of agriculture practices where Acacia pennatula [Fabaceae: Mimosoideae] is grown to give shade to the cattle). In each plot, 10 pitfall traps filled with 75% ethanol were placed. Collembola were sorted, cleared up and mounted under slides in Hoyer's solution. Drawings were done using a phase contrast microscope and a camera lucida. Measurements were done with an ocular micrometer.

Description

Type species Aethiopella flavoantennata (Philiptschenko, 1926).

Diagnosis (modified from Massoud, 1967). Body form variable, but always with paratergites or paratergal areas. Ant. III and IV dorsally fused, the limit between them is only observable in ventral view and precisely at this limit the sense organ is located on Ant III. This consists of 2 rods of variable shape under a cuticular fold. Ant. IV always is longer than Ant. III, with bilobed or trilobed apical bulb, apical pit, microsensillum and several simple sensilla, sometimes similar to setae. Oral cone elongated. The maxillae are always styliform, sometimes with 2 lamella, but never toothed or fringed. Postantennal organ morula-shape, 8 eyes on each side of the head. Unguis with 1 internal tooth. Capitate tenent hairs and empodial appendage absent. Furcula present and well developed.

Aethiopella pilarandresae sp. nov. (Figs. 1 - 13) (2, 3, 4) (5, 6, 7, 8, 9, 10 ) (11, 12)

Holotype (male): Body length 0.68 mm; average (n= 9): 0.75 mm, range 0.6-0.9 mm. Color purplish. Body setae smooth and short, each surrounded by 5 or 6 granules. Cuticle granulose, and paratergites conspicuous on thoracic segments and from Abd. I to III. Ant. I with 7 setae, Ant. II with 11 setae, Ant. III and IV fused dorsally (Fig. 1), with 20-23 setae. Sensory organ of Ant. III with 2 small (2 μm) club-shaped sensilla under a cuticular fold, 2 guard sensilla (sgd and sgv) and ventral microsensillum (Fig. 2). Ant. IV with trilobed apical bulb, 7 sensilla, 1 microsensillum and subapical organite (Fig 1). Eyes 8+8, grouped on 5+3 in each side, with strongly pigmented eye patch. PAO moruliform, twice the size of 1 eye, with 20-27 vesicles (Fig. 5). Mandible with 6 subequal small teeth (Fig. 6). Maxillae styliform, 2 fused lamella, with crochet apex (Fig. 7). Buccal cone typical of the genus. Labium bearing setae A-G (Fig. 8). Dorsal chaetotaxy composed of microsetae (10 μm), mesosetae (15 μm) and long sensilla (35 μm). Sensillar formula by a half tergum: 022/11111. All body setae are simple and smooth (Figs. 3 and 4). Head with microsetae and mesosetae (Fig. 3.). Th. I with 2+2 dorsal setae, Th. II and III with 2 lateral setae. Abd. V with posterior margin straight and abd. VI totally visible (Fig. 4). Chaetotaxy of legs I-III as follows; subcoxa 1-3 setae, coxae 5-6 setae, trochanter 5-6 setae, femora 10-11 setae and tibiotarsi with 2 whorls of setae, proximal with 7 and with 11. Foot complex with 1 pretarsal setae and 1 internal tooth (Fig. 9). Ventral tube with 3+3 setae; tenaculum with 3 teeth on each ramus (Fig. 11). Furcula fully developed: manubrium with 8+8 ventral setae; 3 on each side longer than others; dens 6+6 similar setae; mucro with lamella "spoon-shaped" (Fig. 10). Ratio mucro: dens: 1.7. Each anal valve with 16 setae and 2 setolae (Fig.12), all smooth. Genital plate of female with 3+3 pregenital setae 10 circumgenital and 2 eugenital setae (Fig. 12). Genital plate of male with 3+3 pregenital setae, 12 circumgenital setae and 4+4 eugenital setae (Fig. 13).

Taxonomic summary

Type material: holotype male and 38 paratypes on slides (16 females, 16 males and 6 juveniles). Nicaragua, Mesas de Moropotente (Estelí) 1241 msnm (13º19'30"-13º60'30" N, 86º11'00"-86º22'00" W), 22/VIII/07. Soil and litter, dominant vegetation Senna squineri and Croton jalapensis.

Etimology: named after Dr. Pilar Andrés (Centre de Recerca Ecologica i Aplicacions Forestals, Bellaterra, Barcelona, Spain) for her contributions to soil ecology and collection of the type material.

Remarks. Aethiopella pilarandresae sp. nov. is characterized by the presence of 6 teeth on the mandible, mucro smaller than dens and postantennal organ with 20-27 vesicles, differing from A. ariana in the number of sensilla on Ant. IV (7 vs. 8) and a trilobed apical bulb (vs. bilobed). Furcula is very different, all dental setae on the new species are similar, but in A. ariana 2 distal setae are thicker than others; mucro has a thin complete external lamella while in A. ariana it is thick, incomplete not reaching the tip. The Abd. V of A. pilarandresae sp. nov. has only 2 pairs of setae between the sensorial setae (vs. 3 pairs). The new taxon differs from A. caraibensis in its smaller size (0.6-0.9 vs. 1.2-2.7 mm), the shape of mandible (subequal teeth vs. 1 big basal tooth), the evident sensilla on Ant. IV (vs. inconspicuos), and the number of postantennal vesicles (20-27 vs. 36). A. delamarei has a similar size but differs clearly from the Nicaraguan species in having undifferentiated sensilla on Ant. IV (vs. evident), a small postantennal organ (12-15 vs. 20-27 vesicles) and mandibles with only 4 teeth (vs. 6). A. littoralis is larger than A. pilarandresae sp. nov. (0.8-2.0 vs. 0.6-0.9mm) and has barbulated setae (vs. smooth) and slightly capitate sensorial setae (vs. acuminate), and more mandibular teeth (9-19 vs. 6); additionaly the eugenital setae of males are spiniform (vs. setiform).

Key to the species of Aethiopella.

Acknowledgments

We are grateful to Pilar Andrés (Spain) for the donation of numerous Collembola from Nicaragua, Blanca E. Mejía Recamier (UNAM, México) for clearing and mounting specimens under slides and María Martínez (México) for the preparation of final drawing plates.

Literature cited

Arlé, R. 1960. Collembola Arthropleona do Brasil Oriental e Central. Arquivos do Museu Nacional 49:135-211.         [ Links ]

Bellinger, P. F., K. A. Christiansen and F. Janssens. 1996-2014. Checklist of the Collembola of the world. http://www.collembola.org; last acces; 10.III.2014.         [ Links ]

Fernandes, L. H. and M. C. Mendonça. 2002. Duas novas espécies de Pseudachorutinae (Collembola, Neanuridae) do Brasil. Boletim do Museu Nacional, nova série 496: 1-8.         [ Links ]

Handschin, E. 1942. Materialien zur revision der Collembolen die Gattung Ceratrimeria C.B. sensu Womersley. Verhandlungen der Naturforschenden 53:265-284.         [ Links ]

Massoud, Z. 1967. Monographie des Neanuridae Collemboles Poduromorphes à pièces buccales modifiés. Biologie de l'Amérique Australe 3:1-399.         [ Links ]

Najt, J., J. M. Thibaud and W. M. Weiner. 1990. Collemboles (Insecta) poduromorphes de Guyane Française. Bulletin du Museum National d'Histoire Naturelle, Section A, Zoologie, Biologie et Écologie Animales 12:95-121.         [ Links ]

Thibaud, J. M. and Z. Massoud. 1983. Les Collemboles des Petites Antilles III.- Neanuridae (Pseudachorutuinae). Revue d'Écologie et de Biologie du Sol 20:111-129.         [ Links ]