Three new species of oribatid mites (Acari, Oribatida) from Ecuador

A BSTRACT — Three new oribatid mite species – Ampullobates ecuadoriensis n. sp. , Plenotocepheus neotropicus n. sp. and Monoschelobates hemileiformis n. sp. – are described from Ecuador. The three genera are also new for Ecuador. Ampullobates ecuadoriensis n. sp. is morphologically similar to Ampullobates nigriclavatus Grandjean, but differs from the latter by the morphology of the lamellar, exuvial and some epimeral setae, sensilli, the size of the interlamellar and exobothridial setae and the position of the genital setae. Plenotocepheus neotropicus n. sp. is morphologically similar to Plenotocepheus mollicoma Hammer, but differs by the length of interlamellar setae, morphology of sensilli, localization of lyriﬁssures iad and adanal setae ad 3 and structure of leg setae u . Finally, Monoschelobates hemileiformis n. sp. is morphologically similar to Monoschelobates parvus Balogh and Mahunka, but shows differences in body size, length of the interlamellar, notogastral and anogenital setae and the presence of aggenital setae.


INTRODUCTION
This paper is a part of our ongoing studies on the Ecuadorian oribatid mite fauna (Ermilov and Kalúz 2012a-e). It reports the description of three new species, one belonging to the genus Ampullobates Grandjean, 1962 (Hermanniellidae), one to the genus Plenotocepheus Hammer, 1966 (Tetracondylidae) and another to the genus Monoschelobates Balogh and Mahunka, 1969 (Scheloribatidae).
Ampullobates is a monotypic genus proposed by Grandjean (1962b) with Ampullobates nigriclavatus Grandjean, 1962 as type species. The single known species is distributed in the Neotropical region; this genus is herein recorded for the first time from Ecuador. The main generic characters of Ampullo-bates are presented by Grandjean (1962b), and summarized by Balogh (1988, 1992).
Plenotocepheus is a genus proposed by Hammer (1966) with Plenotocepheus mollicoma Hammer, 1966 as type species. It currently comprises ten species, distributed in the subtropics; this genus is herein recorded for the first time from Ecuador. The main generic characters of Plenotocepheus are presented by Hammer (1966), and summarized by Balogh and Balogh (1992) and Grobler (1995a). Known species of this genus were included in several keys (Grobler 1995a, b;Balogh and Balogh 2002).
Monoschelobates is a genus proposed by Balogh and Mahunka (1969) with Monoschelobates parvus Balogh and Mahunka, 1969 as type species. It currently comprises two species, recorded from Brazil; this genus is herein recorded for the first time from Ecuador. The main generic characters of Monoschelobates are presented by Balogh and Mahunka (1969), and summarized by Balogh and Balogh (1992).
The purpose of this paper is to describe and illustrate three new species, Ampullobates ecuadoriensis n. sp., Plenotocepheus neotropicus n. sp. and Monoschelobates hemileiformis n. sp.

MATERIAL AND METHODS
Specimens were mounted in lactic acid on temporary cavity slides for measurement and illustration. All body measurements are presented in micrometers. Body length was measured in lateral view, from the tip of the rostrum to the posterior edge of the ventral plate, to avoid discrepancies caused by different degrees of notogastral distortion. Notogastral width refers to the maximum width in dorsal aspect. Lengths of body setae were measured in lateral aspect. Terminology used in this paper follows that of Grandjean (1962 a, b), Grobler (1995a, b), Norton and Behan-Pelletier (2009 , 36 -41) and six pairs of setal alveoli. Exuvial setae simple, thick, straight, densely barbed. Notogastral setae c 1 , c 2 , cp, d 1 , d 2 , e 1 ,e 2 , f 1 and f 2 reduced. Only six pairs of notogastral setae well developed: p 1 , h 1 and h 2 (32 -41) dilated distally, slightly serrate; p 2 and p 3 (28 -32) thickened, setiform, straight, slightly barbed; c 3 (16) setiform, thin, smooth. Lyrifissures and opisthonotal gland openings (gla) located typically for the family.
Anogenital region -( Figures 1B; 2I). Seven pairs of genital setae (anterior pair 32 -36; others 16 -20) setiform, smooth inserted in two parallel rows; seventh pair longest (41 -45), inserted separately from others. One pair of aggenital (ag) and Roman letters refer to normal setae (e to famulus); Greek letters to solenidia; d φ and d σ -solenidion and seta coupled. Single prime (ʹ ) marks setae on anterior and double prime (ʺ ) setae on posterior side of the given leg segment. Parentheses refer to a pair of setae.
Legs -( Figure 2J). Typical for Hermanniellidae (Grandjean 1962a;Ermilov and Kalúz 2012a). Claw of each tarsus smooth. Homology of setae and solenidia is indicated in Table 1. Famulus (e) and solenidia setiform. Type deposition -The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; two paratypes are deposited in the collection of the Siberian Zoological Museum, Novosibirsk, Russia; two paratypes are in the personal collection of the first author.
Etymology -The specific name "ecuadoriensis" refers to the country of origin, Ecuador.
Legs -( Figure 4I). Typical for Tetracondylidae (Grobler 1995a;Ermilov et al. 2010). Claw of each tarsus with several small barbs in dorsal side. Homology of setae and solenidia indicated in Table 2. Tarsi I and II with one to two conical teeth on dorsal side. Leg setae u thorn-like on all tarsi. Famulus short, with small swelling distally. Solenidia simple. Etymology -The specific name "neotropicus" refers to the region of origin, the Neotropical region.
Remarks -Plenotocepheus neotropicus n. sp. is most similar to Plenotocepheus mollicoma Hammer, 1966(see Hammer 1966 from New Zealand in the absence of medial notogastral condyles and shape of body setae. However, it is clearly distinguish-able from the latter by the long interlamellar setae, which are longer than the rostral and lamellar setae (interlamellar setae considerably shorter than rostral and lamellar setae in P. mollicoma), sensillar heads weakly pointed distally, shorter than its stalk (sensillar heads with long, thin tip, longer than its stalk in P. mollicoma), lyrifissures iad in direct apoanal position (inverse apoanal in P. mollicoma), distance between adanal setae ad 3 -ad 3 longer than that between ad 2 -ad 2 (shorter in P. mollicoma), and thorn-like leg setae u on tarsi I (setiform in P. mollicoma).
Integument - (Figures 5A-C). Body color brown. Body surface smooth. Posterior part of notogaster and epimeral region with irregular muscle sigilla.
Type deposition -The holotype is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; two paratypes are deposited in the collection of the Siberian Zoological Museum, Novosibirsk, Russia; three paratypes are in the personal collection of the first author.
Etymology -The specific name "hemileiformis" refers to the similarity of the new species to representatives of the subgenus Scheloribates (Hemileius) Berlese, 1916.
Due to the combination of generic characters (in particular, rudimentary pteromorphs, four pairs of sacculi, ten pairs of short notogastral setae, four pairs of genital setae), the species of the genus Monoschelobates are similar to species of the subgenus Scheloribates (Hemileius). Only a single main difference is monodactylous leg tarsi in Monoschelobates versus tridactylous in Scheloribates (Hemileius). Also, the type species of Monoschelobates, M. parvus, is without aggenital setae. Presence or absence of aggenital setae, and variation in numbers of leg claws are not apomorphic characters, therefore it can be used as subgeneric characters. Hence, possibly, Monoschelobates parvus and M. hemileiformis n. sp. should be included in the subgenus Scheloribates (Hemileius). However, the classification of genera in the family Scheloribatidae is difficult, and the further research on the taxonomic status of Monoschelobates is needed.