Lepidozetes baikalensis Ryabinin, 2018

Ryabinin, N. A., 2018, New and little-known species of oribatid mites (Acari: Oribatida) in the mountain areas of Siberia, Far Eastern Entomologist 368, pp. 11-15 : 12-14

Lepidozetes baikalensis Ryabinin , sp. n.

Figs 1–3

MATERIAL. Holotype – ♂, Republic of Buryatia: Tunkinsky District, Eastern Sayan

Mountains, Tunkinsky Golts Range, lichen tundra, h~ 2500 m, 1.VII 1987, collector M.N.

Pyshnenko. Paratype: 1 ♂, same data as holotype. Holotype is deposited in the collection of

Institute of Ecology and Evolution, Russian Academy of Sciences ( Russia, Moscow),

paratype is stored in the collection of Nikolay Ryabinin ( Russia, Khabarovsk) .

DIAGNOSIS. Body size 420 x 250. Body surface smooth. Rostrum rounded. Anterior margin of lamellae concave medially. Interlamellar setae (in) longer than rostral (ro) and lamellar (le) setae. Sensilli (ss) with enlarged, thick head. Tutoria with one tooth. Notogastral setae short, thin, slightly barbed. Tarsus with three claws.

DESCRIPTION. Male. Integument. Light brown mites with smooth covers. Body size

420 x 250.

Prodorsum. Rostrum is broadly rounded with flattened apex. Lamellae are fused, long and broad, cover almost the entire surface of the prodorsum, and do not reach the anterior margin of the rostrum. Anterior margin of lamellae concave medially. Dorsal sides of lamellae rounded. A dark loop is visible on the protruding part of the rostrum. The rostral setae (44) are slightly protrude beyond the apex of the rostrum, stout, begin under the anterior part of the tutoria, and on the outside are covered with numerous bristles. Lamellar setae (53) are slightly thinner than rostral setae, they begin under the anterior part of the lamellae; reach the end of the rostrum. They are almost parallel, covered with rare bristles.

Interlamellar setae (76) are one and a half times as long as lamellar setae, start on well-

marked sclerotized ridges under the hysterosome edge, which is curved forward. They are strong, covered with rare bristles, directed forward and reach the bases of lamellar setae.

Sensilli are on a short, dense stalk with an enlarged, thick head. They are covered with dense hairs (especially on the outside and in the front). In the middle of the head can see a bright space.

Notogaster . Pteromorphs are connected by a bridge. Anterior margins of pteromorphs are without tooth. They protrude a little for the front arcuate edge of the notogaster. Dorso-

phragmata (D) are small, located close to each other. Lenticulus absent. Notogaster is broader in the middle, carries 10 pairs of setae (22-26) covered with small spinules, posterior setae

p 1, p 2, p 3 shorter than other setae. There are four pairs of porose areas, Aa (7) are larger than the others.

The ventral side. Genital (44) and anal (66) openings are small, trapezoidal; the distance between them is about twice the length of the genital. Genital setae 6 pairs, anal 2 pairs,

aggenital 1 pair, adanal 3 pairs. The epimeral formula 3-1-3-3. All ventral setae thin, smooth.

Tarsus with 3 claws.

ventral view; 3 – setae c. Scale bar 1, 2 = 100 µm; 3 = 10µm.

DIFFERENTIAL DIAGNOSIS. There are currently seven species in the genus Lepidozetes Berlese, 1910 : L. acutirostrum Ermilov, Martens et Tolstikov, 2013 , L. bavaricus

Weigmann, 2013, L. dashidorzsi Balogh et Mahunka, 1965 , L. latipilosus Hammer, 1952 , L.

singularis Berlese, 1910 , L. trifolius (Fujikawa, 1972) , and L. umbellatus (Bugrov, 1991)

(Subias, 2017). Of these, three species ( L. bavaricus , L. latipilosus and L. singularis ) do not have a medial notch on lamellae. L. baikalensis sp. n. differs from L. acutirostrum by the absence of a small prong on the apex of the rostrum, clavate sensilli on a short stalk (in L.

acutirostrum they with lanceolate head), convex sejugal furrow, protruding beyond the sejugal furrow with the upper edges of the pteromorph. From L. dashidorzsi the new species differs in smaller size ( L. dashidorzsi size 0.5–0.56 mm), clavate sensilli on a short stalk (in

L. dashidorzsi they are spindle-shaped), by pteromorphs outstanding for the sejugal furrow.

L. baikalensis sp. n. has significant differences from L. trifolius , described from Japan (Fujikawa, 1972). L. trifolius has a smaller size (0.3 mm), bacillus smooth sensilli, very short lamellar and interlamellar setae, the anterior margin of the pteromorph does not protrude beyond the sejugal furrow, and also 1 claw on the legs. L. umbellatus has spindle-shaped sensilli with a pointed apex, in addition, it has 5 genital setae and somewhat larger (0.56 mm)

than L. baikalensis sp. n.

NOTES. The systematic position of species of the genus Lepidozetes needs to be clarified.

Presence or absence of medial notch, 1–3 claws on legs, 5–6 pairs of genital setae – all this requires more detailed consideration.

NEW RECORD

The second interesting species of oribatid mites is also found in Buryatia. Data on finding of Lamellovertex sp. in the eastern part of the Palaearctic was mentioned earlier (Ryabinin,

2007). Here this species is identified as Lamellovertex caelatus (Berlese 1895) . The specimens from Buratia have some differences from the European specimens. I consider it necessary to give a brief description and a drawing of this species.