Description of juvenile stages and adults of two new nothroid mites from Ecuador (Acari: Oribatida: Nothridae)

The morphology of juvenile stages and adults of two new Neotropical oribatid mites from Ecuador is described and illustrated: Nothrus cotopaxiensis n. sp. and N. glaesarius n. sp. Comparison is made with juvenile stages and adults of similar species: Ethiopian species N. ifeensis Badejo, Woas and Beck, 2002, Japanese N. meakanensis Fujikawa, 1999 and N. silvestris Nicolet, 1855. Specimens were found in samples of moss, soil, litter, detritus from the forest patch, from under dwarf shrubs, below shrubs bordering the creek and in cushion plants. All samples were collected from Ecuador (provinces Pichincha, Imbabura and Cotopaxi, at 2750–3900 m a.s.l.).


Introduction
The moss-mite genus Nothrus (Oribatida: Crotonioidea: Nothridae) occurs throughout the whole world excluding the Antarctic Region. Only 12 species have been described from the Neotropical region so far (Subías 2004). In this paper juvenile stages and adults of two new species are described and compared to similar representatives of the genus.
The present paper is part of a study of the crotonioid mite fauna of Ecuador, based on the results of the circumtropical collecting programme launched in 1963 by Prof. J. Balogh. He and his co-workers concentrated the collecting partly in the Andes mountain range, partly in the Amazon Basin. They endeavoured to collect in all vegetation zones and these collections were extended with the aim to visit every country in South America, particularly Ecuador (Balogh 1988(Balogh , 1989Kuty 2005Kuty , 2006.
Several collecting expeditions in the Galápagos Island were carried out by Prof. H. Schatz. Among 202 oribatid species, which were encountered from these Ecuadorian islands, there were only two nothrid species: Nothrus biciliatus C. L. Koch, 1844and N. oblongus Hammer, 1961(Schatz 1998.

Materials and methods
The descriptions are based on the material from the Basel Natural History Museum, Switzerland. All samples were collected by Prof. A. Zicsi and Dr. I. Loksa from the provinces of Pichincha, Imbabura and Cotopaxi in Ecuador.
The mites were preserved in 75% ethanol and cleared in lactic acid. Two adults of Nothrus cotopaxiensis, one tritonymph and two adults of N. glaesarius were used in SEM. Specimens were examined with a scanning electron microscope in the Electron and Confocal Microscope Laboratory, A. Mickiewicz University, Poznań , Poland. They were mounted on stubs with double-sided stickytabs, coated with gold in a Balzers SPC 050 ion coater, and observed in a Philips 515 scanning electron microscope.
The holotype and eight paratypes of Nothrus cotopaxiensis n. sp., the holotype and 14 paratypes of N. glaesarius n. sp. are stored in the Basel Natural History Museum, Switzerland. Comparative material is stored in the collection of Dr. Ziemowit Olszanowski (Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Poznań , Poland).
All specimens of N. cotopaxiensis (two larvae and 14 adults) come from four samples and N. glaesarius (one larva, two protonymphs, one deutonymph, four tritonymphs and 19 adults) from four samples. litter and soil from below shrubs bordering the creek.
Morphological terminology used in the descriptions follows that developed by F. Grandjean (see Travé and Vachon (1975) for references). Surface of prodorsum with round pits. Rostrum with median incision. Setae ro small, phylliform and frayed, bent, set on tubercles. Setae le similar to ro, set on apophyses. Setiform setae in shorter than le. Sensilli setiform, third as long as in. Setae ex setiform, half as long as in.
Notogaster narrowed posteriorly. Two pairs of elongated folds of thickened chitin run from setae c 1 -c 2 to f 1 . Surface of plate covered with distinct, large, round pits; with 12 pairs of frayed and phylliform setae. Setae c 2 as long as in, placed closer to c 1 than to c 3 . Setae h 1 longest, as long as distance between them. Oval opening of opisthosomal gland (gla) situated close to seta f 2 .
All legs monodactylous (setation not studied).  Prodorsal surface with round pits. Setae le three times longer than ro. Setae in frayed, as long as le. Sensilli thin, distally notched, almost twice longer as distance between their bases. Setae ex setiform and short.
Notogaster broadest at level of setae e 2 . Two pairs of elongated folds of thickened chitin run from setae c 1 -c 2 to e 2 . Surface of plate between folds covered with distinct, large, round pits; lateral surface with small pits, posterior part with sparse pits. With 16 pairs of frayed and phylliform setae, thinner than in larva. Setae c 2 placed closer to setae c 1 than to c 3 . Setae h 2 longest, as long as distance between their bases and as sensilli. Oval opening of opisthosomal gland (gla) situated close to seta f 2 .

Remarks
The adult of Nothrus cotopaxiensis n. sp. shows some similarity to the Ethiopian species Nothrus ifeensis Badejo, Woas and Beck, 2002 and to the Japanese species N. meakanensis Fujikawa, 1999. All these species have long sensilli and one of the setae h elongated. However, N. cotopaxiensis n. sp. differs from these species by tarsi with three claws and frayed, phylliform setae. Comparison of selected morphological characters of adults of the above-mentioned species is given in Table I. Fujikawa (1999) presented short descriptions of the larva and tritonymph of N. meakanensis, including figures of selected setae. The larva of N. cotopaxiensis n. sp. is similar to the larva of N. meakanensis having setae ro and le frayed, equally long. However, the larva of N. cotopaxiensis has sensilli three times shorter than setae in, setae ex as long as ss and broader, longer notogastral setae.

Etymology
Nothruscotopaxiensis n. sp. is named after its locus typicus, Cotopaxi National Park, Ecuador.
Surface of notogastral plate covered with small pits and folds. With 12 frayed and phylliform notogastral setae, except setae h 1 , which are equal in width, with uneven margins. Setae c 1 , c 3 , d 1 , d 3 , e and h 2 half the length f 1 ; d 2 third as long as f 1 . Setae c 2 quarter as long as c 1 , placed closer to c 1 than to c 3 . Setae f 2 shorter than f 1 but longer than e 2 . Setae h 1 almost three times longer than f 1 , with branched caves inside. Oval opening of opisthosomal gland (gla) situated below seta f 2 .
Protonymph (Figures 18-29) Body length: 470 mm, body width: 230 mm; colour: white, light brown Setae ro as long as half of the distance between their bases. Setae in longer and broader than ro, notched. Sensilli 1.5 times longer than distance between their bases, slightly barbed and apically pointed. Setiform setae ex three times shorter than ro.
Surface of notogastral plate covered with small pits. With 16 frayed notogastral setae, except setae h 1 . Setae c 1 , c 3 , d, e, f 1 and h 3 half shorter than f 2 . Setae c 2 shorter than c 3 , placed closer to c 1 than to c 3 . Setae h 1 as long as f 2 , with branched pits, set on apophyses. Setae h 2 as long as their mutual distance, apically narrowed, with branched pits. Setae p 1 as long as distance p 1 -h 2 , with branched caves inside, on apophyses. Setae p 2 longer than h 3 ; p 3 similar to ro. Oval opening of opisthosomal gland (gla) situated near seta f 2 .

Deutonymph (Figures 30-43)
Body length: 630 mm, body width: 310 mm; colour: light brown Surface of prodorsum with small pits. Setae ro almost twice longer than distance between their bases. Setae le similar to in.
Setae p 2 as long as h 3 . Other notogastral setae similar to protonymphal setae. Oval opening of opisthosomal gland (gla) situated below seta f 2 .
All legs monodactylous (setation not studied). Tritonymph (Figures 44-53, 75-78) Body length: 670 mm, body width: 320 mm; colour: light brown Setae ro half shorter than distance between their bases. Setae le as long as ro. Setae in twice longer and broader than le. Setiform setae ex half shorter than ro. With 16 frayed and narrower than deutonymphal notogastral setae. Setae c 2 as long as le, placed closer to c 1 than to c 3 . Setae h 3 similar to h 1 . Setae p 1 longer than distance p 1 -h 2 . Setae p 2 shorter than c 2 ; p 3 half shorter than p 2 . Other notogastral setae similar to deutonymphal setae. Oval opening of opisthosomal gland (gla) situated below seta f 2 .
Adult (Figures 54-66     Setae ro pointed distally, almost as long as their mutual distance. Setae le and in similar to ro in length. Sensilli longer than distance between their bases, completely barbed, distally pointed. Setae ex short, setiform.
Surface of notogastral plate covered with pits of different sizes. Shape of notogastral setae similar to tritonymphal setae. Setae c 2 and c 3 equally long, shorter than c 1 ; c 2 placed closer to c 1 than to c 3 . Setae h 1 almost twice longer than c 3 . Setae h 2 almost as long as their mutual distance. Setae h 3 similar to h 1 . Setae p 1 as long as distance p 1 -h 2 .    Pairs of epimeres medially connected. Epimeral setation: 6-6-5-4. Genital plates with nine pairs of setae; two pairs of anal and three pairs of adanal setae.

Remarks
The adult Nothrus glaesarius n. sp. is similar to the Japanese species N. meakanensis Fujikawa, 1999 andN. silvestris Nicolet, 1855. These species have similar notogastral setae and apically pointed, entirely barbed sensilli. Nothrus glaesarius differs from both species in  its tridactylous tarsi, shorter sensilli and longer setae ro, le and shorter notogastral setae. However, the relationship of described species to bidactylous (but sometimes mono-or tridactylous) N. silvestris needs further study (Olszanowski 1996). Comparison of selected morphological characters of adults of the above-mentioned species is given in Table II.  Seniczak (1992) described the morphology of the larva and tritonymph of N. silvestris. Moreover, he also noted epimeral setation and body measurements of the other juvenile stages. An analysis of the ontogeny shows differences between N. glaesarius and N. silvestris, as indicated in Table III.    the longest, shaped the longest, baciliform the longest, baciliform Epimera 6-6-5-4 5-3(4)-5-4(5) (6, 7)-(4, 5)-(5, 6)- (4,6) access to the specimens and the curator of the Basel Natural History Museum, Switzerland for the loan of material. Special thanks to the Journal editor, Dr. P.J. Hayward (Department of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea, UK) and reviewers for all valuable advice.