Rare Spider Species Research Articles

New Data to the Rare Spider Species (Arachnida, Aranei) from Kyiv Region (Ukraine)

Seven rare spider species collected in the Kyiv Region are listed. Eresus moravicus Řezáč, 2008, Parasyrisca arrbonica Szinetár & Eichardt, 2009, and Enoplognatha bryjai Řezáč, 2016 are recorded for the first time from the East European Plain. P. arrbonica and E. bryjai are new to the spider fauna of Ukraine; Atypus muralis Bertkau, 1890, A. piceus (Sulzer, 1776), and Mustelicosa dimidiata (Thorell, 1875) are new the Kyiv Region. Comments on the geografical distribution and illustrations of four species are provided.

Gnaphosa badia (Araneae: Gnaphosidae) in the Ukrainian Carpathians with comments on its distribution

An analysis of data on the distribution of the rare spider species Gnaphosa badia (L. Koch, 1866) (Araneae: Gnaphosidae) is presented. Until recently, this species had been recorded in the Carpathian Mountains at two localities: Mt. Chorna Hora (Ukraine, Volcanic Ridge) and the Rodna Mountains (Romania). It was subsequently discovered that the species occurs within the subalpine and alpine zones of the Ukrainian (Eastern) Carpathians, in the Chornohora and Rakhiv Mountain massifs. Part of the material was included in a checklist of the spiders of the Chornohora Mountain massif. The species compositions of the alpine and subalpine spider communities, which include G. badia, are given. The total distribution of the species is discussed and shown on a map.

Rare spider species (Araneae) of protected steppe areas of the Kharkiv Region (Ukraine)

A total of 426 spider species is known in the fauna of the Kharkiv Region. Of these, 32 species may be considered rare and/or vulnarable. The largest steppe areas in the Kharkiv Region are protected in the National Nature Park “Dvorichanskyi” and the Regional Landscape Park “Velykoburlutskyi Steppe”. The former hosts 11 rare spider species, the latter 13 species, and eight species occur in both Parks. For the species Lathys heterophthalma, Trachyzelotes lyonneti, Russocampus polchaninovaе, and Euryopis laeta it is the only valid record from Ukraine; for Pardosa maisa, Dipoena coracina, and Talavera aperta, maximun two or three localities are known. Titanoeca veteranica and Altella hungarica are the new records to the Kharkiv Region. Two species are extremely rare, Altella hungarica has been found in only seven localities in Europe, and Russocampus polchaninovae in four localities. Northern boundaries of the geographic ranges of Civizelotes pygmaeus, Gnaphosa dolosa, Xysticus marmoratus, X. mongolicus, and the southern boundary of Gnaphosa lugubris run through the Kharkiv Region. On the edges of their areas, these species become habitat specialists and occur only in steppes and/or dry meadows. Xyticus mongolicus inhabits sandy and chalky steppes with sparse vegetation. Gnaphosa taurica has high ecological plasticity in the steppe zone, while in the forest-steppe, it is limited with chalk and limestone outcrops. Some species like Gnaphosa lugubris, G. licenti, G. taurica, Zora pardalis and Eresus kollari, were abundant in our samplings while 19 species were found as singletons. G. taurica, and E. kollari preferred chalky slopes, G. licenti both chalky slopes and top of a southern ungrazed slope, G. lugubris dominated on all slopes in the Velykoburlutskyi Steppe, while Z. pardalis was the most abundant in ungrazed gully bottoms in both Parks. Being not numerous, Altella hungarica, Euryopis laeta, Civizelotes pygmaeus and Drassyllus vinealis occurred annually in the same habitats that may indicate stability of their populations. Given their habitat specificity, even numerous species became vulnerable under the threat of anthropogenic transformation of natural ecosystems. The only way to protect them is to preserve their habitats.

Notes on the Italian distribution of Dolomedes plantarius (Clerck, 1757), species assessed for the IUCN Red List (Araneae: Pisauridae)

The great raft spider, Dolomedes plantarius, is a semi-aquatic spider species with an Eurosiberian distribution. As a result of habitat loss and degradation, in 1996 the species was classified as Vulnerable in the IUCN Red List of Threatened Species, but since then the status has never been updated. We present the frame of the existing knowledge on the distribution of this rare spider species in Italy, based on literature data and on original records gathered in recent years. Finally, we discuss the conservation value of the Italian populations, in light of their peripheral position within the species range and in light of the future reduction of the bioclimatic range of the species due to climate and land cover changes associated with anthropic disturbance

Two rare spider species (Araneae: Araneidae, Theridiidae) found in the Šumava Mts.

Abstract During an arachnological survey in the Šumava National Park in 2016, two very rare spider species were discovered: Araneus saevus (Araneidae) was recorded for the second time, 45 years after its first report in the Czech Republic. The species is therefore no longer regionally extinct, and can be considered critically endangered. Theridion boesenbergi (Theridiidae) was recorded for the first time in the Šumava Mts. Ecological characterisation of the species is improved, being more psychrophilous than was previously expected. Almost all collected specimens of both species from the Czech Republic are deposited in the National Museum in Prague.

Design and Implementation of a Shape Shifting Rolling–Crawling–Wall-Climbing Robot

Designing an urban reconnaissance robot is highly challenging work given the nature of the terrain in which these robots are required to operate. In this work, we attempt to extend the locomotion capabilities of these robots beyond what is currently feasible. The design and unique features of our bio-inspired reconfigurable robot, called Scorpio, with rolling, crawling, and wall-climbing locomotion abilities are presented in this paper. The design of the Scorpio platform is inspired by Cebrennus rechenbergi, a rare spider species that has rolling, crawling and wall-climbing locomotion attributes. This work also presents the kinematic and dynamic model of Scorpio. The mechanical design and system architecture are introduced in detail, followed by a detailed description on the locomotion modes. The conducted experiments validated the proposed approach and the ability of the Scorpio platform to synthesise crawling, rolling and wall-climbing behaviours. Future work is envisioned for using these robots as active, unattended, mobile ground sensors in urban reconnaissance missions. The accompanying video demonstrates the shape shifting locomotion capabilities of the Scorpio robot.

New records of several rare spider species (Araneae) from south-eastern Poland

The paper presents new data on seven rare spider species in Poland: Anelosimus vittatus, Clubiona corticalis, Nusoncus nasutus, Pocadicnemis carpatica, Pseudicius encarpatus, Pseudomaro aenigmaticus and Talavera thorelli. Their current locations is presented on maps. Moreover, the figures illustrating the main diagnostic features of Clubiona corticalis, Pseudomaro aenigmaticus and Talavera thorelli are included.

Rare spider species (Araneae) from the Giant Mountains and the Izera Mountains – new records for the fauna of Poland

We present data on four spider species (Araneae) new for the fauna of Poland. The spiders were found predominantly in the mires of the Giant Mountains and the Izera Mountains (the Western Sudetes). Some of these habitats are the transborder mires between Poland and the Czech Republic. The presented species are: Erigone cristatopalpus, Panamomops sulcifrons, Theridion boesenbergi, Gnaphosa lapponum. Each of these spiders is rare or lives in specific habitat.

The distribution and habitat preferences of an extremely rare European spider, <i> Glyphesis taoplesius </i>(Araneae: Linyphiidae)

Glyphesis taoplesius Wunderlich, 1969 is a very rare spider species that has only been found in a few locations in Europe. Two specimens of G. taoplesius were recently collected in the Bug river valley in eastern Poland. It is the first record of this species in Poland. A morphological description of the male and a distribution map of the species are given in the paper. G. taoplesius is a hygrophilous spider typically found near bodies of water and the Polish specimens were found in a periodically flooded meadow.

Agroeca dentigeraandEntelecara omissa(Araneae: Liocranidae, Linyphiidae) found in Sweden.

The rare spider species Agroeca dentigera Kulczynski, 1913 (Liocranidae) and Entelecara omissa O. P.-Cam- bridge, 1902 (Linyphiidae), have been found in a small coastal freshwater fen in Lomma (55°42'N 13°4'E), north of Malmo in Scania in southernmost Sweden. A. dentigera was also found on a salt water meadow south of Malmo. Both species have been found only in a few wet localities in Europe. Entelecara depilata Tullgren, 1955, is a junior synonym of Entelecara omissa O. P.-Cambridge, 1902, new synonymy.

Maro sublestus Falconer, 1915 (Araneae, Linyphiidae) - a species new to the fauna of Poland

A rare spider species, Maro sublestus Falconer, 1915 (Linyphiidae) is reported from Poland for the first time. It was found in the Karkonosze National Park, in a wet habitat. Some taxonomic comments are included in the paper.

An Experimental Test for Predator-Mediated Interactions among Spider Species

The primary objective of this study was to test the hypothesis that lizards intensify interactions among spider species. The most abundant lizard and web-spider species (Anolis sagrei and Metepeira datona, respectively), were manipulated within field enclosures over a 30-mo period. The design was a 2 × 2 factorial: A. sagrei present and removed, crossed with M. datona present and removed. A. sagrei reduced abundance of Eustala cazieri, the second most abundant web spider, and tended to reduce abundance of all rare spider species combined. M. datona had no significant effect on abundance of E. cazieri or of all rare species combined. In each statistical analysis of abundance, the A. sagrei × M. datona interaction term was not significant, indicating that lizards did not intensify (or reduce) interactions among spider species. Furthermore, data on spider food supply, body length, and web height showed no evidence for two proposed mechanisms in which interactions among spider species are stronger with lizards than without. Thus, this experiment supports the hypothesis that direct predation is the major mechanism by which lizards reduce the abundance and species richness of spiders.

AN EXPERIMENTAL TEST FOR PREDATOR-MEDIATED INTERACTIONS AMONG SPIDER SPECIES

The primary objective of this study was to test the hypothesis that lizards intensify interactions among spider species. The most abundant lizard and web-spider species (Anolis sagrei and Metepeira datona, respectively), were manipulated within field enclosures over a 30-mo period. The design was a 2 × 2 factorial: A. sagrei present and removed, crossed with M. datona present and removed. A. sagrei reduced abundance of Eustala cazieri, the second most abundant web spider, and tended to reduce abundance of all rare spider species combined. M. datona had no significant effect on abundance of E. cazieri or of all rare species combined. In each statistical analysis of abundance, the A. sagrei × M. datona interaction term was not significant, indicating that lizards did not intensify (or reduce) interactions among spider species. Furthermore, data on spider food supply, body length, and web height showed no evidence for two proposed mechanisms in which interactions among spider species are stronger with lizards than without. Thus, this experiment supports the hypothesis that direct predation is the major mechanism by which lizards reduce the abundance and species richness of spiders.

Lizards Reduce Spider Species Richness by excluding Rare Species

To assess the impact of lizards on species richness and properties of individual species of web spiders, we conducted a 4.5-yr field experiment on Staniel Cay, Exumas, Bahamas. Spider populations were censused at ∼2-mo intervals in lizard-removal enclosures and in control enclosures with lizards present at natural densities. Lizards reduced total number of individuals, species richness (number of species), and composite diversity of web spiders. The differential absence of rare species was primarily responsible for the lower species richness in controls than in lizard-removal enclosures. The impact of lizards on the abundance of Metepeira datona, the numerically dominant spider species, was weaker than the impact on the abundance of all rarer species combined. Mean body lengths of Argiope argentata, a large, rare spider, were larger in removals than in controls, whereas mean body lengths of M. datona, a small, common spider, did not differ significantly in removals and controls. A. argentata were closer to the ground than two commoner species and thereby were potentially more vulnerable to lizard predation. The present mainland-enclosure experiment and an island-introduction experiment both demonstrated the same general pattern of lizard predation: exclusion of rare spider species. However, the impact of lizards on spiders was more devastating in the island experiment. Other experimental field studies that had terrestrial animals as subjects and that separately analyzed at least all common species in a prey assemblage demonstrated that predators reduced or had no effect upon prey species diversity. Each study in which predators reduced diversity indicated that local extinction of rare species in experimental areas with predators was common.

LIZARDS REDUCE SPIDER SPECIES RICHNESS BY EXCLUDING RARE SPECIES

To assess the impact of lizards on species richness and properties of individual species of web spiders, we conducted a 4.5-yr field experiment on Staniel Cay, Exumas, Bahamas. Spider populations were censused at ∼2-mo intervals in lizard-removal enclosures and in control enclosures with lizards present at natural densities. Lizards reduced total number of individuals, species richness (number of species), and composite diversity of web spiders. The differential absence of rare species was primarily responsible for the lower species richness in controls than in lizard-removal enclosures. The impact of lizards on the abundance of Metepeira datona, the numerically dominant spider species, was weaker than the impact on the abundance of all rarer species combined. Mean body lengths of Argiope argentata, a large, rare spider, were larger in removals than in controls, whereas mean body lengths of M. datona, a small, common spider, did not differ significantly in removals and controls. A. argentata were closer to the ground than two commoner species and thereby were potentially more vulnerable to lizard predation. The present mainland-enclosure experiment and an island-introduction experiment both demonstrated the same general pattern of lizard predation: exclusion of rare spider species. However, the impact of lizards on spiders was more devastating in the island experiment. Other experimental field studies that had terrestrial animals as subjects and that separately analyzed at least all common species in a prey assemblage demonstrated that predators reduced or had no effect upon prey species diversity. Each study in which predators reduced diversity indicated that local extinction of rare species in experimental areas with predators was common.