Ground-dwelling Spiders Research Articles

Copulatory behavior of Microstigmatidae (Araneae: Mygalomorphae): a study with Xenonemesia platensis from Argentina

Abstract Microstigmatidae are small ground-dwelling and free-living spiders. The present study reports on the copulatory behavior of Xenonemesia platensis Goloboff 1989, constituting the first report on sexual behavior of the Microstigmatidae. Our findings in X. platensis did not show evidence of pheromones associated with silk. The courtship behavioral units of males was comprised of quivers by legs I and II, brusque movements of the palps, and leg tapping with legs II. During mating, a novel courtship behavior by males was observed that consisted of tapping and scraping with legs II on the female legs. The present study not only gives a description of mating behavior in Microstigmatidae for the first time, but also reports strong evidence of nongenital copulatory courtship activity in mygalomorph spiders.

Effects of diet and salinity on the survival, egg laying and metabolic fingerprints of the ground-dwelling spider Arctosa fulvolineata (Araneae, Lycosidae)

Soil salinity and the salinity of trophic resources may alter the osmoregulatory processes of arthropod, challenging the smooth regulation of body water, and, ultimately, survival. The intra and extracellular build-up of osmolytes represent a common strategy to attenuate acute hyperosmotic stress in several arthropod species. In the present study, we aimed to determine the impact of substrate and trophic resource salinities on salt tolerance in the female wolf spider, Arctosa fulvolineata, which is considered a specialist salt marsh species. We evaluated adult female survival and egg laying, and quantified the osmo-induced accumulation of compatible solutes (GC–MS). Three concentrations of substrate salinity were tested (0‰, 35‰ and 70‰) under three trophic conditions (starved spiders, spiders fed with salt prey [intertidal amphipods] and spiders fed with unsalted prey [freshwater amphipods]). We found no support for diet preferences in female A. fulvolineata, which exhibited similar predation rates on freshwater and marine amphipods. Survival and egg-laying were significantly impaired when female A. fulvolineata were exposed to hypersaline conditions for 12days. Our results showed an increase in the level of several compatible solutes when spiders were exposed for 12days to saline conditions. For instance, α-alanine, β-alanine, arginine, asparagine, aspartate, homoserine, glutamine, glycine, proline and serine levels were 4–10 times higher under hypersaline conditions. The osmo-induced accumulation of amino acids may increase the osmolality of body fluids, thus enhancing the smooth regulation of body fluids and survival ability of wolf spider under extreme saline conditions.

A new species of Caloctenus (Araneae: Ctenidae) from Colombia

The genus Caloctenus Keyserling, 1877 comprises four species of small (3–7 mm) ground-dwelling spiders found in cloud forests and adjacent habitats of the northern Andes of South America, at elevations between 1800 to 2600 m (Silva 2004). All species apparently have a restricted geographic range and most are only known from the type locality. These spiders exhibit a cryptic coloration having a dark brown body with iridescent scales, sparse white plumose hairs and club-shaped red hairs, an ornamentation pattern that makes them indistinguishable from the leaf litter and hard to find. Recent attempts to find more caloctenine spiders in a Peruvian type locality were unsuccessful and it appears their populations, in general, are declining as fast as are their mossy and humid microhabitats.

Short-Term Response of Soil Spiders to Cover-Crop Removal in an Organic Olive Orchard in a Mediterranean Setting

This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity.

Can mixed species stands enhance arthropod diversity in plantation forests?

Tree species composition is a key driver of forest biodiversity, influencing structural components of the environment from soil and litter to vegetation layers and the canopy, and ecosystem processes, such as nutrient cycling. Single species stands, particularly intensively managed monoculture plantations, are typically more homogenous in habitat structure and the biotic communities supported, than mixed stands. Thus, international forest policy increasingly promotes the establishment of mixed stands as an alternative to enhance biodiversity in plantations. Forests represent around 10% of the land area of Ireland, with most being monocultures of non-native conifers. By contrast, natural forest cover, primarily comprised of deciduous species, is just 1%. In recent years there has been an increase in mixed plantations; however, optimum tree species combinations, which aim to promote biodiversity under sustainable forest management, have yet to be established. Arthropods (ground-dwelling spiders and Carabid beetles, and night-flying macrolepidoptera) were examined in twenty mixed and monoculture plantations in Ireland (Norway spruce–oak mix, Norway spruce–Scots pine mix, Norway spruce monoculture). Both oak and Scots pine were secondary mix components, comprising between 15% and 40% of stems. Spiders and Carabid beetles were sampled using pitfall traps during summer 2008 and moths using light traps during summer and autumn 2008 and spring 2009.There was no evidence for an influence of oak or Scots pine on the arthropod fauna when they were a secondary component in a mix. Overall, arthropod communities were similar in species richness, assemblage structure and habitat specialists among the forest types. Furthermore, the mixed stands exhibited similar environmental conditions to monocultures in terms of stand structure, vegetation and litter cover. This suggests that there is limited biodiversity value from an additional canopy species comprising 15–40% of the mix, at least for the taxa and tree species studied here. This has implications for forest policy, where recommendations are often based on the proportion of each mix component, at least in terms of the potential biodiversity value of additional canopy species. Further research is required to determine the proportion at which oak or Scots pine begin to influence the arthropod fauna.

Responses of ground-dwelling spiders (Araneae) to variable retention harvesting practices in the boreal forest

Green tree retention has been embraced as an alternative to large scale conventional clear-cutting aimed at managing the boreal forest in a more sustainable way. Ground-dwelling spider assemblages were studied 6 years after the application of variable retention harvesting practices (dispersed to 2%, 10% and 75% retention vs. aggregated retention) in deciduous and coniferous dominated stands as part of the Ecosystem Management Emulating Natural Disturbances (EMEND) project in the mixedwood boreal forest of northwestern Canada. Overall, spider composition was dominated by open-habitat species, especially by the wolf spider Pardosa moesta Banks, in all harvest treatments. However, an important shift in species composition was observed in unharvested controls. Distinctive ground-dwelling spider assemblages were observed in each forest cover-type and these were highly affected by the various harvest treatments, especially in coniferous forests. From the 164 species collected, 37 were indicators for various combinations of forest type, harvesting treatment and retention level. Species richness was affected as harvesting intensity increased; however, greater impact was observed in dispersed retention than in aggregated retention, and in coniferous stands compared to the same treatment in deciduous stands. Dispersed retention, even at 10%, seemed to mitigate adverse effects of harvesting on spider assemblages, but only in deciduous forests; however, important effects on biodiversity were observed in coniferous forests even after 75% retention. Retention of aggregated patches was useful in maintaining forest specialist species after harvesting, but was more effective when applied together with dispersed retention. Responses of spider assemblages to harvesting seemed to be highly correlated with environmental changes. Green tree retention preserves some of the heterogeneity, structural features and environmental conditions required by forest specialist species and thus becomes an effective management practice to maintain forest biodiversity, especially when both aggregated and dispersed retention practices are applied together. However, the effectiveness of these practices varies depending on the forest cover-type prior to harvesting and the amount of post-harvest residual. This suggests that a single prescription is insufficient for maintaining landscape heterogeneity, and that a combination of prescriptions is supported for a more sustainable management of the mixedwood boreal forest.

Partial cutting does not maintain spider assemblages within the observed range of natural variability in Eastern Canadian black spruce forests

In boreal black-spruce forests of Eastern Canada, a cohort model of ecosystem management has been proposed whereby a combination of both partial and more intensive cutting are used to emulate old-growth stands and the re-establishment of stands following severe wildfire. As with other approaches to coarse filter conservation, partial cutting is hypothesized to maintain and potentially recreate plant and animal assemblages consistent with a range of natural variability. In this study, we used ground-dwelling spiders (Araneae) to evaluate whether partial cutting and a cohort model of ecosystem management are sufficient to preserve biodiversity found in mature and over-mature boreal black spruce stands prone to paludification. We compared the spider fauna (11,628 individuals representing 136 species) in replicated partial cuts, clear cuts and uncut control stands with a chronosequence of mature and over-mature naturally regenerated stands (94–288 years since the last fire) [25 stands in total] in the same region of the northern Clay belt in Québec (Canada). In stands that were old-growth prior to cutting, harvesting had strong repercussions on spider assemblages that were not attenuated by less intensive, partial cutting. The most obvious changes in spider assemblages were related to increased recruitment of species that were nearly absent in uncut stands. Several cosmopolitan species that were widely distributed among stands prior to harvest increased in cut stands. Spider assemblages collected following either cutting methods were not consistent with assemblages found within the chronosequence and thus fell outside the observed range of natural variability. However we did not observe a similar recruitment effect for spider species in younger stands with relatively higher levels of retention. We demonstrate that the interaction between stand age prior to cutting, the degree of paludification as well as remnant basal area are important considerations when evaluating the efficacy of partial cutting to maintain forest spider assemblages and biodiversity at large in black-spruce stands. “We also suggest that retention levels in partial cuts will have to be substantially increased to maintain spider communities within their range of natural variation in managed forested landscapes.” However partial cutting with higher levels of retention, particularly in younger stands, may be useful in coarse filter management particularly for establishing or accelerating spider assemblages towards those found in old-growth stands.

Citrus-orchard ground harbours a diverse, well-established and abundant ground-dwelling spider fauna

Ground-dwelling spider assemblages comprise one of the most representative predatory groups to be found in manycrops. There is some evidence of the role that ground-dwelling spiders play in controlling certain citrus pests; however, thereare almost no studies about the abundance and composition of this predatory group in citrus orchards. A three-year surveyconducted using pitfall traps in three citrus orchards in Eastern Spain yielded more than five-thousand ground-dwellingspiders belonging to more than 50 species and 20 families. Wandering families such as Lycosidae, Gnaphosidae andZodariidaewere the most numerous in terms of captures. The generalist predator Pardosa cribata Simon (Araneae: Lycosidae) was the most common species, representing a quarter of all captures, followed by Zodarion cesari Pekar. (Araneae: Zodariidae) and Trachyzelotes fuscipes (Koch) (Araneae: Gnaphosidae). Spiders were active throughout the year with a peak population in summer. The species abundance data for the three spider assemblages sampled fitted a log normal statistical model which is consistent with a well-established community. The presence of a cover crop provided higher abundance of alternative prey and consequently higher abundance and diversity of ground-dwelling spiders. This work demonstrates that the citrus-orchard ground harbours a diverse and abundant ground-dwelling spider fauna, which is also active throughout the year. A challenge for future studies will be to establish conservation management strategies for these predators, that will improve biological control of those citrus pests that inhabit or spend part of their life cycle on the orchard floor.

Spatial and temporal structure of the spider community in the clay semi-desert of western Kazakhstan

The spatial and temporal structure of spider communities was studied in the clay semi-desert of the north-western Caspian Lowland, western Kazakhstan (49°23' N, 46°47' E). The soils and vegetation are complex, being composed of a mosaic of desert and steppe plant communities. Besides the native associations, there are plantations of different tree species. The ground-dwelling spider assemblages in the native habitats are the most diverse. The number of species inhabiting forest plantations is three times as small. Gnaphosidae is the leading family in the ground layer. They show high abundance and diversity levels during the whole season. Thomisidae, Lycosidae, Philodromidae, and Salticidae are abundant as well. The species diversity of herbage-dwelling spiders in different open native habitats is very similar. The spectrum of dominant families (Thomisidae, Oxyopidae, Araneidae, and Salticidae) and the seasonal dynamics of their ratio in desert and steppe associations have much in common. Spider assemblages of native and artificial habitats are characterised by change from multispecies polydominant spring-summer communities to impoverished imbalanced autumn ones. Seasonal changes in the species structure of mature spider groupings in native habitats are well pronounced, while the impact of seasonal conditions is even stronger than between-habitat differences. Complexes of typical species with different levels of habitat preference are revealed.

Integrative taxonomy uncovers hidden species diversity in woodlouse hunter spiders (Araneae, Dysderidae) endemic to the Macaronesian archipelagos

The development of molecular techniques as a taxonomic tool and their integration with information provided by other disciplines, has enhanced species discovery, facilitated species delimitation and produced invaluable data for inferring species phylogenies. Here, we provide an example of how DNA sequence data, together with morphometric, distributional and ecological information, assist in identifying and diagnosing previously overlooked lineages. The nocturnal, ground-dwelling spider genus Dysdera has colonized all the Macaronesian archipelagos, and has undergone a major diversification in the Canary Islands. A recent molecular phylogenetic analysis of Dysdera species from the eastern Canary Islands revealed deep genetic divergences among some populations, suggesting the existence of cryptic taxa. Here, we combine data from mitochondrial and nuclear loci with morphological and ecological evidence to delimit and formally describe three previously overlooked species: D. aneris sp. nov., endemic to the Salvage Islands; D. mahan sp. nov., distributed along coastal habitats of Lanzarote, north of Fuerteventura and adjacent islets; and D. simbeque sp. nov., restricted to two valleys in northern Lanzarote. Molecular markers provide key information that allows apparent morphological polymorphisms to be used as diagnostic features of evolutionarily independent lineages. Dysdera mahan sp. nov. is unique among the Canarian Dysdera in that it is found in the intertidal zone on pebbled beaches. Low levels of genetic variability and genital differentiation associated with relatively high somatic divergence suggest that speciation in D. mahan sp. nov. was driven by a selection of phenotypic traits that are adaptive to this rare environment. Separate analyses and statistical tests revealed phylogenetic incongruence between mitochondrial and nuclear genes, probably as a result of incomplete lineage sorting. The temporal framework for the origin and diversification of the new species inferred from the molecular data corroborates former hypotheses on the late Pliocene origin of the present-day biota of the Salvage Islands.

Determinants of ground-dwelling spider assemblages at a regional scale in the Yukon Territory, Canada

Arctic fauna is undergoing significant alteration in response to global climate change, yet we know little regarding the factors that determine species assemblages at northern latitudes. We used a latitudinal transect to assess environmental determinants of ground-dwelling spider assemblages across the boreal forest-tundra transition at a regional scale. Using multivariate techniques, we tested 3 complementary hypotheses regarding the factors that best explain patterns of assemblage structure. We predicted that spider assemblages would respond most strongly to vegetation composition and structure and that climate and spatial variables would explain less of the variation in the data. We sampled ground dwelling spiders using pitfall traps placed at 36 sites along the latitudinal transect. We constructed 3 separate matrices of spatial, climate, and vegetation variables, with each matrix representing a hypothesis. We used redundancy analysis with variation partitioning to determine which matrix of environmental variables best explained patterns in a matrix of spider abundances. We then used a separate redundancy analysis to determine which environmental variables best explained the variation in measures of species richness and activity density. We collected a total of 2890 individual spiders representing 103 species, 58 genera, and 13 families. Our analysis supports the hypothesis that vegetation composition and its related structure best explain patterns in northern spider assemblages at a regional scale.

Seasonal variation of ground spiders in a Brazilian Savanna

The Brazilian Savanna Ecoregion (Cerrado) is one of the richest biomes in the world, with a characteristic highly seasonal climate a dry season between May and September and a rainy season from October through April. Ground-dwelling spiders from three Cerrado phytophysiognomies, "campo cerrado", "cerrado" and "cerradão", were sampled using pitfall traps during two years, totaling 111 species and 3,529 individuals. The abundance of individuals and species richness was higher during the wet season. Fifty-eight species were captured exclusively during that period, whereas only nineteen were restricted to the dry season. Only two species were found in all samples. The number of juveniles was higher than the number of adults in all phytophysiognomies and in all species during both seasons. The highest abundance was registered in October and the lowest in April. Overall sex ratio was male-biased in all vegetation types sampled. Distinct climate variables affected the abundance of spiders depending on sex, age and vegetal physiognomy where they were sampled. This study involved the longest sampling of spider abundance and diversity on the ground of a Brazilian Savanna.

Effects of the abandonment of alpine summer farms on spider assemblages (Araneae)

In parallel with the current effects and responses to climate change ongoing changes of land use strongly affect alpine areas. The aim of this study was to analyse spider assemblages occurring on farmlands with differing stages of land use intensity. We collected the ground-dwelling spider fauna of semi-natural grasslands in currently farmed and abandoned farmland in the alpine zone of Hardangervidda, Norway, using pitfall traps. Trapping during the whole vegetation period resulted in 1,548 individuals belonging to 39 species of spiders. Linyphiids and lycosids dominated. The total number of species differ little between sites, but there was a general trend of increasing proportions of lycosids, gnaphosids and thomisids individuals and species, and a decrease in the proportion of linyphiids with farmland abandonment. Two main groupings of spider assemblages were found using a principal component analysis: One grouping was characteristic of intensely disturbed sites, mainly dominated by typical pioneer species. The other was characteristic of abandoned and less disturbed sites, dominated by widespread species. The abandonment of summer farms led to a succession in spider assemblages, including a decline in spider species with a high ballooning activity and an increase of species with a larger body size. We suggest that the main reason lies in the absence of disturbance by grazing including differing vegetation architecture and the proportion of bare ground with abandonment. Spider assemblages react quickly to environmental changes that occur in alpine habitats after abandonment. Thus, it is necessary to include spiders and other invertebrate animal indicator groups in field studies and experiments dealing with grazing impacts on alpine habitats.

Effects of vegetation management by mowing on ground-dwelling arthropods

Species-rich grasslands are rare in the Netherlands and need consistent vegetation management to retain their characteristic biodiversity. Roadside verges are important refuges for grassland plants since the mowing management no longer aims at traffic safety only but also strives for botanical diversity. Although arthropods are highly abundant in roadside verges, the effect of different mowing practices on this group is largely unknown. During 4 years, we studied ground beetles, weevils, ants and ground-dwelling spiders with pitfall traps in experimental plots in roadside verges with five different mowing treatments: (i) no management, (ii) and (iii) mowing once a year with and without hay removal, (iv) and (v) mowing twice a year with and without hay removal. This was done in a plant productivity gradient; the experiment was repeated in low-, medium- and high-productive verges. In the low-productive site, the effect of management on the arthropods only existed in a higher abundance in plots mown twice per year with hay removal. In the medium- and high-productive sites, mowing twice a year with hay removal resulted not only in highest abundances but also in highest arthropod species richness. Mowing twice without hay removal and mowing once with removal showed intermediate values, while mowing once per year without removal and particularly the absence of management resulted in low diversity and low abundance. To promote ground-dwelling arthropods in medium-to-high-productive grassland verges, we recommend a management of mowing twice a year with the removal of hay. It is reasoned that some form of rotational management, aiming at leaving some vegetation refuges intact after mowing events, may further promote arthropod survival. However, caution should be taken that these refuges are not too large, as overall suitability for ground-dwelling arthropod decreases rapidly in such patches. Out of several studied vegetation characteristics, the number of flowering plant species (medium-productive verge) and total flower abundance (high-productive verge) appeared to represent suitable, and easily monitored, proxies that significantly mirror arthropod diversity.

First Report of the GenusSesieutesSimon (Araneae: Liocranidae) from China, with Description of One New Species

The ground-dwelling spider genus Sesieutes Simon, 1897, belonging to the family Liocranidae, is reported from China for the first time, and detailed diagnoses are reviewed. A new species of the genus Sesieutes from Yunnan Province, China, and Chiang Mai Province, Thailand, is diagnosed, described and illustrated under the name of Sesieutes zhui sp. nov.

Effects of urbanization on ground-dwelling spiders in forest patches, in Hungary

Effects of urbanization on ground-dwelling spiders (Araneae) were studied using pitfall traps along an urban-suburban–rural forest gradient in Debrecen (Hungary). We found that overall spider species richness was significantly higher in the urban sites compared to the suburban and rural ones. The increased diversity was due to the significantly more open-habitat species in the assemblages at the urban sites. This suggests that species from the surrounding matrix (grasslands and arable lands) penetrated the disturbed urban sites. The ratio of forest species was significantly higher in the rural sites than in the suburban and urban ones, suggesting that forest species are indeed sensitive to the disturbance caused by urbanization. Canonical correspondence analysis revealed that the species composition changed remarkably along the urbanization gradient. Open-habitat spiders were associated with the urban sites of higher ground and air temperature. Forest spiders were characteristic of the rural sites with higher amount of decaying woods. Our findings suggest that the overall diversity was not the most appropriate indicator of disturbance; species with different habitat affinity should be analyzed separately to get an ecologically relevant picture of the effect of urbanization.

Patterns in the composition of ground-dwelling spider communities in the Pilbara bioregion, Western Australia

Patterns in the composition of ground-dwelling spider communities in the Pilbara bioregion, Western Australia

SPIDER FAUNA AND INFLUENCE OF TRAPPING METHOD AND FIELD MARGIN ON SPIDER POPULATION DENSITY IN SUGAR BEET FIELDS

Experiments were carried out at the experimental farm of Sakha Agricultural Research Station in 2006/07 and 2007/08 sugar beet seasons. The spiders inhabiting the sugar beet fields were surveyed, which indicated to the occurrence of 30 spider species belonging to Araneidae, Dictynidae, Dysderidae, Gnaphosidae, Linyphiidae, Lycosidae, Miturgidae, Philodromidae, Salticidae, Tetragnathidae, Theridiidae and Thomisidae. In all sugar beet plantations (August, September and October), the pitfall traps captured more spiders of families Lycosidae and Gnaphosidae (Ground-dwelling spiders) and Philodromidae and Salticidae (wandering spiders) than did D-vac machine which captured more linyphiids and araneids (orb-weaver spiders). Population density of spiders in the field margins were usually greater than that inside the field for the seven considered families. Traps used inside the field captured less spiders than those used in the margins by 32.50-82.14 % overall spider families.

Spiders and Scorpions (Arachnida: Araneae, Scorpiones) of the Nylsvley Nature Reserve, South Africa

Among other activities, the South African National Survey of Arachnida (SANSA) aims to survey the biodiversity of arachnids in protected areas of South Africa. The study presented here documents the diversity of spiders and scorpions collected from the Nylsvley Nature Reserve (NNR), South Africa over a 30-year period. The spider fauna of NNR contains 175 species (7.5% of the total recorded in South Africa), in 131 genera and 37 families. Thomisidae is the most diverse spider family in the reserve, with 33 species (18.9% of the total), followed by Salticidae, with 20 species (11.4%), and Araneidae, with 18 species (10.3%). The majority of species (125) are wandering spiders (71.4%), whereas 50 species (28.6%) build webs. Wandering grounddwelling spiders comprise 52 species, whereas 73 wandering species have been collected from the vegetation. A total of 158 species are new records for the reserve and Oxyopes tuberculatus Lessert, 1915 is newly recorded for South Africa. Six spider species may be new to science. The scorpion fauna of NNR comprises five species (5% of the total recorded in South Africa) in three genera and two families. Buthidae are more diverse in the reserve, with four species and two genera represented. The scorpion fauna of the reserve includes two fossorial and three epigeic species, representing five ecomorphotypes: semi-zpsammophilous, pelophilous, lithophilous, corticolous and lapidicolous. Five additional scorpion species may be recorded if the reserve is sampled more intensively using appropriate techniques.

Responses of ground-dwelling spiders to four hedgerow species on sloped agricultural fields in Southwest China

Spiders are important predators in agroecosystems and contribute to the control of agricultural pest populations. Habitat management such as the creation of new semi-natural habitats around or within fields enhances spider abundance and species diversity. Using pitfall traps, we investigated the effects of four hedgerow plant species, which serve as undisturbed and permanent semi-natural habitats, on ground-dwelling spider activity density (a parameter of population density and relative activity) and species richness. Samples were collected over two winter wheat and two summer maize growing seasons during 2005–2007 in trial field 1 (slope gradient of 20%) and field 2 (slope gradient of 12%) at the Ziyang Experimental Site in Sichuan Province, China. The hedgerow species evaluated were Amorpha fruticosa (field 1), Vetiveria zizanioides (field 1), Eulaliopsis binata (field 2), and Medicago sativa (field 2). Compared to control plots, hedgerow plots had significantly higher activity density and species richness of ground-dwelling spiders within strips in both fields 1 and 2 during the wheat growing season. The presence of hedgerow strips did not augment the activity density and species richness of ground-dwelling spiders within the crop fields during the wheat or maize growing seasons. The ground-dwelling spider activity density within hedgerow strips was significantly higher in the Vetiveria than in the Amorpha plots and in the Medicago than in the Eulaliopsis plots, and the species richness was significantly higher in the Vetiveria than in the Amorpha plots during the wheat season. Our results suggest that hedgerows may serve as important overwintering sites for ground-dwelling spiders during the wheat growing season. In addition, the diversification of agroecosystems by using hedgerow strips may be a viable strategy for maintaining ground-dwelling spider populations in agricultural areas. However, ground-dwelling spiders did not move into adjacent crop fields; therefore, future work should address the mechanisms of attracting spiders into crop fields, thereby contributing to the bio-control of pests.