Forty-two years of scientific research on eight legs-celebrating the 60th birthday of Dr Yuri M. Marusik.

The biography of Dr Yuri Mikhailovich Marusik is presented, and his scientific life illuminated on the occasion of his 60th birthday. Yuri is a renowned specialist of spiders. He has described 718 new species, 57 new genera, and two new subfamilies of order Araneae. Twenty-five species and one genus have been dedicated to him. Facts and impressions are given as well as a bibliography of his 545 publications.

Circumpolar terrestrial arthropod monitoring: A review of ongoing activities, opportunities and challenges, with a focus on spiders.

The terrestrial chapter of the Circumpolar Biodiversity Monitoring Programme (CBMP) has the potential to bring international multi-taxon, long-term monitoring together, but detailed fundamental species information for Arctic arthropods lags far behind that for vertebrates and plants. In this paper, we demonstrate this major challenge to the CBMP by focussing on spiders (Order: Araneae) as an example group. We collate available circumpolar data on the distribution of spiders and highlight the current monitoring opportunities and identify the key knowledge gaps to address before monitoring can become efficient. We found spider data to be more complete than data for other taxa, but still variable in quality and availability between Arctic regions, highlighting the need for greater international co-operation for baseline studies and data sharing. There is also a dearth of long-term datasets for spiders and other arthropod groups from which to assess status and trends of biodiversity. Therefore, baseline studies should be conducted at all monitoring stations and we make recommendations for the development of the CBMP in relation to terrestrial arthropods more generally.

On two enigmatic spiders (Araneae: Cybaeidae amp; Phrurolithidae) from the Russian Far East.

Cybaeota Chamberlin Ivie, 1933, a genus previously known only in the Nearctic, has been found in the Maritime Province of Russia for the first time. It is represented by a new species, C. wesolowskae sp. nov. (♂♀), which is close to the generotype, C. calcarata (Emerton, 1911). Additionally, a new species, Phrurolithus lindemanni sp. nov. (♀), is described from the Maritime Province as well. It has unusually light colouration in comparison to other congeners. Trans-Pacific disjunctive ranges on species, genus and family levels in arthropods are briefly discussed.

Status and trends of terrestrial arthropod abundance and diversity in the North Atlantic region of the Arctic.

The Circumpolar Biodiversity Monitoring Programme (CBMP) provides an opportunity to improve our knowledge of Arctic arthropod diversity, but initial baseline studies are required to summarise the status and trends of planned target groups of species known as Focal Ecosystem Components (FECs). We begin this process by collating available data for a relatively well-studied region in the Arctic, the North Atlantic region, summarising the diversity of key terrestrial arthropod FECs, and compiling trends for some representative species. We found the FEC classification system to be challenging to implement, but identified some key groups to target in the initial phases of the programme. Long-term data are scarce and exhibit high levels of spatial and temporal variability. Nevertheless, we found that a number of species and groups are in decline, mirroring patterns in other regions of the world. We emphasise that terrestrial arthropods require higher priority within future Arctic monitoring programmes.

Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland.

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.

Redescription of the Himalayan Trachelas costatus (Araneae: Trachelidae).

O. Pickard-Cambridge (1885) described Trachelas costata based on female specimens from two localities in the Himalayas. Since then it was only mentioned in two works by Simon (1897, 1906). The World Spider Catalog (2018) indicates its distribution as "China (Yarkand)". All of the species described by O. Pickard-Cambridge (1885), based on material collected during the Second Yarkand Mission, are stored in the Oxford University Museum of Natural History. Vials with material described in this paper contain no species and locality labels (Prószynski Zochowska 1981; Marusik 1993). It was not difficult to recognize the syntypes of this species due to the figures given by O. Pickard-Cambridge, and also because it is the only trachelid described from Yarkand to date. The goals of our paper are to redescribe Trachelas costatus in detail, designate a lectotype, and comment on its distribution and relationships.

Taxonomic notes on the armored spiders of the families Pacullidae and Tetrablemmidae (Arachnida, Araneae) from Singapore.

Eight species of armored spiders belonging to two families, Pacullidae Simon, 1894 and Tetrablemmidae O. Pickard-Cambridge, 1873, are reported from Singapore. Five species are documented as new to science: Paculla bukittimahensis Lin & Li, sp. n. (male and female), Paculla globosa Lin & Li, sp. n. (male and female), Ablemma malacca Lin & Li, sp. n. (male and female), Singaporemma lenachanae Lin & Li, sp. n. (male and female), and Sulaimania brevis Lin & Li, sp. n. (male). The three known species are Brignoliella besutensis Lin, Li & Jäger, 2012, Brignoliella michaeli Lehtinen, 1981, and Singaporemma singulare Shear, 1978, of which the female of Brignoliella besutensis is described for the first time. For comparison, types of Singaporemma adjacens Lehtinen, 1981 from Vietnam, Singaporemma halongense Lehtinen, 1981 from Vietnam, Singaporemma singulare from Singapore and Sulaimania vigelandi Lehtinen, 1981 from Malaysia are studied and photographed.

First description of the male of the easternmost Harpactea species, H. parthica (Araneae: Dysderidae).

Within Dysderidae, Harpactea Bristowe, 1939 (178 species) is second only to Dysdera Latreille, 1804 (264 species) in number of species (WSC 2016). Harpactea is distributed from Portugal (Helsdingen 2015) to eastern Iran (Brignoli 1980) and, although there are many publications dealing with the taxonomy of Harpactea, an inclusive revision of the genus has never been done. In a paper on the Dysderidae of the Caucasus Dunin (1992) provided a regional revision of Harpactea.

On the synonymy of two Acantholycosa species (Araneae, Lycosidae) from the Altai.

Two species previously known from East Kazakhstan, Acantholycosa katunensis Marusik, Azarkina & Koponen, 2004, known from the holotype male, and Acantholycosa kurchumensis Marusik, Azarkina & Koponen, 2004, syn. n. known from females, are synonymized, and priority is given to Acantholycosa katunensis. Acantholycosa katunensis is reported for the first time in the Russian Altai. Both sexes of this species are illustrated, and a distribution map is provided.

A survey of East Palaearctic Lycosidae (Araneae). 11. Two new genera from the Acantholycosa complex.

Two new genera of wolf spiders belonging to Pardosinae, Gulocosa gen. n. and Melecosa gen. n., are erected to accommodate Gulocosa eskovi sp. n. (♂ ♀, Khabarovsk Province, Russia) and Sibirocosa alpina Marusik, Azarkina & Koponen, 2004, respectively. A new combination was also established: Melecosa alpina (Marusik, Azarkina & Koponen, 2004) comb. n. (ex. Sibirocosa). Polytomous and dichotomous keys are provided for the Palearctic Pardosinae genera.

A redescription of the ant mimicking spider Myrmecium gounellei (Araneae: Corinnidae, Castianeirinae), with notes on the genus.

Myrmecium Latreille, 1824 is a relatively large genus of Castianeirinae with 16 species, distributed exclusively in the Neotropics (WSC 2015). Although this genus is rather well known as a good example of ant mimicking spiders, its taxonomy is very poorly studied. Two of its species are described based on unknown sex; one species is described based on a juvenile; eight species are known based on a single sex: for seven, only females are known, and for one, only a male is known (Platnick 2014). Eleven species are known from a single record, and two species were never illustrated. The latest taxonomic paper dealing with Myrmecium was published more than 60 years ago by Camargo (1953). Although both sexes are known for six species of Myrmecium, the male palp and female epigyne are illustrated for three species only. The male palp is relatively well illustrated for the type species of the genus, M. rufum Latreille, 1824 (Camargo 1953). Somatic characters are illustrated also only for M. rufum (Simon 1897).

Redescription of "Nesticus" citrinus (Taczanowski, 1874) (Araneae, Araneoidea) from French Guyana.

"Nesticus" citrinus, a species originally placed in Theridion is redescribed based on the syntype series composed by 7 females and a lectotype is designated. All syntypes have broken emboli in their epigynes. Taxonomic position of "Nesticus" citrinus is briefly discussed and its belonging to Nesticidae is doubted.

Redescription of three species of Filistatidae (Araneae) described by C.F. Roewer from Afghanistan.

Types of three filistatid species described by Roewer (1960, 1962) from Afghanistan are redescribed and two of them transferred to other filistatid genera. The new combinations proposed are: Zaitunia afghana (Roewer 1962) comb. n. (ex. Filistata Latreille, 1810) and Tricalamus lindbergi (Roewer, 1962) comb. n. (ex. Pritha Lehtinen, 1967). The taxonomic position of Pholcoides afghana Roewer, 1960 is discussed and the species is placed in the filistatid subfamily Prithinae Gray, 1994.

A survey of the East Palaearctic Lycosidae (Araneae). 9. Genus Xerolycosa Dahl, 1908 (Evippinae).

Three species of Xerolycosa: Xerolycosa nemoralis (Westring, 1861), Xerolycosa miniata (C.L. Koch, 1834) and Xerolycosa mongolica (Schenkel, 1963), occurring in the Palaearctic Region are surveyed, illustrated and redescribed. Arctosa mongolica Schenkel, 1963 is removed from synonymy with Xerolycosa nemoralis and transferred to Xerolycosa, and the new combination Xerolycosa mongolica (Schenkel, 1963) comb. n. is established. One new synonymy, Xerolycosa undulata Chen, Song et Kim, 1998 syn.n. from Heilongjiang = Xerolycosa mongolica (Schenkel, 1963), is proposed. In addition, one more new combination is established, Trochosa pelengena (Roewer, 1960) comb. n., ex Xerolycosa.

A review of the Holarctic genus Tmeticus Menge, 1868 (Araneae, Linyphiidae), with a description of a new genus.

Eight species attributed to Tmeticus are reviewed; five are redescribed and illustrated: Tmeticus affinis (Blackwall, 1885), Tmeticus bipunctis (Bösenberg & Strand, 1906), Tmeticus nigriceps Kulczynski, 1916, Tmeticus ornatus (Emerton, 1914) and Tmeticus tolli Kulczynski, 1908. The new genus, Paratmeticus gen. n. is erected for Tmeticus bipunctis, and a new combination is established: Paratmeticus bipunctis (Bösenberg & Strand, 1906), comb. n. Three species names: Gongylidium vile Kulczynski, 1885, syn. n., Tmeticus difficilis Kulczynski, 1926, syn. n. and Tmeticus dubius Kulczynski, 1926, syn. n., are synonymized with Tmeticus tolli Kulczynski, 1908. Although Gongylidium vile has date priority over Tmeticus tolli it is synonymized because of the lack of usage. Three species from Japan attributed to Tmeticus: Tmeticus neserigonoides Saito & Ono, 2001, Tmeticus nigerrimus Saito & Ono, 2001 and Tmeticus vulcanicus Saito & Ono, 2001 are not related to Tmeticus affinis, the type species of the genus, and their affinities remain unclear. The male of Tmeticus nigriceps is described for the first time.