Pachyseius

Marchenko, Irina I., 2015, A new species of Pachyseius Berlese (Acari: Pachylaelapidae) from South Siberia (Russia), with a key to the species known from Asia, Zootaxa 3905 (2), pp. 221-232 : 230

Key to the females for the species of the genus Pachyseius known from Asia

The key provided for separation of ten Pachyseius species known from Asia, was based on previously published keys to the world species of Mašán & Fenďa (2014), Özbek & Halliday (2014) and the original illustrations and descriptions of Pachyseius species known from Asia.

The holotype of P. orientalis deposited in collections of ISEA, Novosibirsk was examined. This species is characterised by having the peritrematal shields fused with the dorsal shield anteriorly, peritremes long, extending anteriorly to a level between enlarged gland gdj 3 and z 1 seta; and trochanter I with six setae. These features were analysed in the preparation of the key. Distribution data of P. humeralis including Canary Islands based on Moraza & Peňa, 2005 b.

1. Anterior margin of sternal shield with a pair of horn-like projections anterior to seta St1; presternal shields absent; posterior part of peritermatal shields fused to exopodal shields IV....................................................... 2

- Anterior margin of sternal shield without horn-like projections; presternal shields present; posterior part of peritermatal shields free, abutting exopodal shields IV........................................................................ 5

2. Dorsal idiosoma with 29 pairs of slightly spatulate setae (z1 absent)................. P. cavernicola Ishikawa, 1989 ; Japan

- Dorsal shield with 30 pairs of acicular setae................................................................. 3

3. Ventri-anal shield with four pairs of pre-anal setae (Jv1-Jv3, Zv2)................. P. sinicus Yin, Lu & Lan, 1986 ; China

- Ventri-anal shield with at most three pairs of pre-anal setae..................................................... 4

4. Epistome triangular, with narrow distal projection; small sclerites between peritrematal and ventri-anal shields present; cir- cum-anal setae longer than anus............................................. P. chenpengi Ma & Yin, 2000 ; China

- Epistome subrectangular, with anterior margin regularly rounded; small sclerites between peritrematal and ventri-anal shields absent; circum-anal setae as long as anus.............................. P. huanrenensis Chen, Bei & Gao, 2009 ; China

5. Ventri-anal shield with three pairs of pre-anal setae (Jv1-Jv3).................................................. 6

- Ventri-anal shield with two pairs of pre-anal setae (Jv1, Jv2).................................................... 7

6. Marginal and ventral soft integument with eight pairs of setae (including r6).......................................................................................... P. humeralis Berlese, 1910 ; Europe; Canary Islands, Caucasus

- Marginal and ventral soft integument with six pairs of setae (including r6)..... P. masani Özbek & Halliday, 2014 ; Turkey

7. Tarsus II with at most three spur-like setae; presternal area weakly reticulate; ventri-anal shield suboval, slightly widened ante- riorly......................................................... P. angustus Hyatt, 1956 ; Europe; Iran, Caucasus

- Tarsus II with one or two spur-like seta; one pair of sclerotised presternal shields present; ventri-anal shield subtriangular form with obvious anterolateral expansion...................................................................... 8

8. Tarsus II with two spur-like setae, marginal and ventral soft integument with 11 pairs of setae; trochanter I with five setae.................................... P. anisimovi sp. nov.; Russia: South Siberia (Altai, West and East Sayan Mountains)

- Tarsus II with one spur-like setae, marginal and ventral soft integument with 12–19 pairs of setae, trochanter II with six setae.................................................................................................... 9

9. Marginal and ventral soft integument with 12 pairs of setae, ventri-anal shield with expanded anterolateral margins abutting metapodal shields; peritrematal shield at level of stigmata is greatly expanded.................................................. P. orientalis Nikolsky, 1982 ; Russia: south of Far East, South Siberia (East Sayan and Altai Mountains); China

- Marginal and ventral soft integument with 19 pairs of setae, ventri-anal shield not conspicuously expanded anterolaterally;