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Arthropods were inventoried in crop fields and adjacent woody hedgerows of organic and conventional farms situated in south-central Ontario, Canada. The objective was to assess the total abundance, family richness, and composition of beneficial and phytophagous arthropods in the 2 farming systems and to examine the contributions of the vegetation present and landscape features on arthropod abundance and composition. Two hundred and forty sticky traps were installed (24 sites) and 170 sweep net collections were conducted (17 sites) in crop fields and adjacent woody hedgerows of organic and conventional sites. A total of 30 807 individual arthropods belonging to 131 families were recorded during the study. No spatial autocorrelation was detected among the arthropod samples. The study showed that beneficial and phytophagous arthropod abundance differed between organic and conventional sites (only with sweep net) but family richness did not. Beneficial arthropods were more abundant in woody hedgerows, while phytophagous arthropods were more abundant in crop fields. This study also demonstrated a strong relationship between plant and arthropod composition. Habitats (total old field cover, total hedgerow length, and Shannon diversity index, all within 250 m radius) in the surrounding landscape influenced arthropod composition but were not leading factors in explaining richness and abundance. It is therefore of prime importance to consider both local factors (management practices and local vegetation) and regional factors such as landscape features as explanatory variables when attempting to explain biodiversity. Nomenclature: Gleason, 1963; Hitchcock & Chase, 1971.

The renewable energy sector is growing at a rapid pace in northern Chile and the solar energy potential is one of the best worldwide. Therefore, many types of solar power plant facilities are being built to take advantage of this renewable energy resource. Solar energy is considered a clean source of energy, but there are potential environmental effects of solar technology, such as landscape fragmentation, extinction of local biota, microclimate changes, among others. To be able to minimize environmental impacts of solar power plants, it is important to know what kind of environmental conditions solar power plants create. This study provides information about abiotic and biotic conditions in the vicinity of photovoltaic solar power plants. Herein, the influence of these power plants as drivers of new microclimate conditions and arthropods diversity composition in the Atacama Desert was evaluated. Microclimatic conditions between panel mounts was found to be more extreme than in the surrounding desert yet beneath the panels temperature is lower and relative humidity higher than outside the panel area. Arthropod species composition was altered in fixed-mount panel installations. In contrast, solar tracking technology showed less influence on microclimate and species composition between Sun and Shade in the power plant. Shady conditions provided a refuge for arthropod species in both installation types. For example, Dipteran s were more abundant in the shade whereas Solifugae s were seldom present in the shade. The presented findings have relevance for the sustainable planning and construction of solar power plants.

Declines in species diversity resulting from anthropogenic alterations of the environment heighten the need to develop management strategies that conserve species and ecosystem services. This study examined how native plant species and their diversity influence the abundance and richness of beneficial arthropods, a functionally important group that provides ecosystem services such as pollination and natural pest suppression. Beneficial arthropods were sampled in replicated study plots containing native perennials planted in one-, two-, and seven-species mixtures. We found plant diversity had a positive impact on arthropod richness but not on arthropod abundance. An analysis of arthropod community composition revealed that each flower species attracted a different assemblage of beneficial arthropods. In addition, the full seven-species mixture also attracted a distinct arthropod community compared to single-species monocultures. Using a multivariate approach, we determined whether arthropod assemblages in two- and seven-species plots were additive and could be predicted based on assemblages from their component single-species plots. On average, assemblages in diverse plots were nonadditive when compared to assemblages predicted using single-species plots. Arthropod assemblages in two-species plots most closely resembled those of only one of the flower species in the mixture. However, the arthropod assemblages in seven-species plots, although statistically deviating from the expectation of an additive model, more closely resembled predicted communities compared to the assemblages found in two-species plots, suggesting that variability in arthropod community composition decreased as planting diversity increased. Our study demonstrates that careful selection of plants in managed landscapes can augment beneficial arthropod richness and support a more predictable arthropod community, suggesting that planning and design efforts could shape arthropod assemblages in natural as well as managed landscapes to meet targeted conservation or management goals.

We argue that the genetic diversity of a dominant plant is important to the associated dependent community because dependent species such as herbivores are restricted to a subset of genotypes in the host-plant population. For plants that function as habitat, we predicted that greater genetic diversity in the plant population would be associated with greater diversity in the dependent arthropod community. Using naturally hybridizing cottonwoods (Populus spp.) in western North America as a model system, we tested the general hypothesis that arthropod alpha (within cross-type richness) and beta (among cross-type composition) diversities are correlated with cottonwood cross types from local to regional scales. In common garden experiments and field surveys, leaf-modifying arthropod richness was significantly greater on either the F1(1.54 times) or backcross (1.46 times) hybrid cross types than on the pure broadleaf cross type (P. deltoides Marshall or P. fremontii Watson). Composition was significantly different among three cross types of cottonwoods at all scales. Within a river system, cottonwood hybrid zones had 1.49 times greater richness than the broadleaf zone, and community composition was significantly different between each parental zone and the hybrid zone, demonstrating a hierarchical concentration of diversity. Overall, the habitats with the highest cottonwood cross-type diversity also had the highest arthropod diversity. These data show that the genetics of habitat is an important conservation concept and should be a component of conservation theory.

We conducted a cropping systems experiment in central Pennsylvania, USA, to determine the effects of initial cover crop species and soil management on the abundance and composition of the ground-dwelling arthropod community. We hypothesized that we would detect legacy effects of the cover crops planted in year 1 of a 3-yr crop sequence on the arthropod community in the subsequent 2 yrs, and that these effects would be influenced by the intensity of tillage. We compared four systems in a factorial combination of perennial sod and legumes or annual cereal grain and legume as initial cover crops and moldboard or chisel plow tillage implemented in soybeans followed by maize in the subsequent 2 yrs. The entire experiment was initiated twice in adjacent locations, starting in 2003 (Start 1) and 2004 (Start 2). We quantified soil arthropod activity-density and community composition and identified all arthropods to order or family, and the ground and tiger beetles (Coleoptera: Carabidae) to species. In Start 1, but not Start 2, arthropod activity-density increased with each year following implementation of organic management. We observed few legacy effects of cover crop or tillage intensity on arthropod activity-density. The composition of the soil arthropod community was primarily defined by the initial cover crop in the first year, and by the interaction between cover crop and tillage intensity in the second and third year. A legacy effect associated with a yr-1 cover crop of cereal rye was observed for Scarabaeidae beetles and Formicidae (ants) in yr 2 and Carabidae beetles in yr 3 of Start 1, but not Start 2. Weed indicators contributed significantly to the variation in the soil arthropod community that was explained by the environment in yr 2 in Start 1, and in yr 3 in both Starts. Our observations support the concept that both immediate and legacy effects of management shape arthropod communities during the organic transition period, suggesting that transitioning systems could be managed in ways that conserve or enhance natural enemy populations.

Heather (Calluna vulgaris) and broom (Cytisus scoparius), originally from Europe, are the main invasive plants on New Zealand’s North Island Central Plateau, where they threaten native flora and fauna. Given the strong link between arthropod communities and plants, we explored the impact of these invasive weeds on the diversity and composition of associated arthropod assemblages in this area. The arthropods in heather-invaded areas, broom-invaded areas, and areas dominated by the native species mānuka (Leptospermum scoparium) and Dracohyllum (Dracophyllum subulatum) were collected and identified to order. During summer and autumn, arthropods were collected using beating trays, flight intercept traps and pitfall traps. Diversity indices (Richness, Shannon’s index and Simpson’s index) were calculated at the order level, and permutational multivariate analysis (PERMANOVA) was used to explore differences in order-level community composition. Our results show a significant variation in community composition for all trapping methods in both seasons, whereas invasive plants did not profoundly impact arthropod order richness. The presence of broom increased arthropod abundance, while heather was linked to a reduction. Under all possible plant pairings between heather, broom, mānuka, and Dracophylum, the impact of neighbouring plant identity on arthropod community composition was further explored for the samples collected using beating trays. The results suggest that during plant invasion, arthropod communities are affected by neighbouring plant identity and that impacts vary between arthropod sampling methods and seasons.

Urban green spaces (UGS) enhance the quality of life in urban environments and serve as habitat corridors or refuge for organisms, including beetles and spiders. The attributes of UGS allow them to harbour species that offer essential ecosystem services. However, the ability of UGS to provide services is limited by the extent to which they have been altered anthropogenically. We described the taxonomic richness and functional composition of arthropods in a mountainous urban ecosystem of Ghana by focussing on the activity of both beetles and spiders at the family level. Two main land-use types (woodlands and built-up areas) were identified and characterised based on the presence or absence of certain vegetation attributes. Sixteen plots in each land-use type with sizes 20 × 20 m were demarcated and fitted with four pitfall traps in each plot to sample continuously for eight weeks, the activity density of both beetles and spiders. Samples were sorted into families and functional groups (detritivores, fungivores, herbivores and predators). The taxonomic richness and activity density were both significantly higher in the woodlands than in the built-up areas. Similarly, all functional groups showed a higher affinity to the woodlands than the built-up areas. Habitat attributes defined by plant diversity and structural complexity were the underlying drivers explaining the differences in arthropod communities between the land-use types. Though the built-up areas seem degraded and open, the remaining small vegetation patches still support the activities of some taxa that should merit the protection of such remnant vegetation in urban ecosystems.

The long-standing tradition of classifying South Africa's biogeographical area into biomes is commonly linked to vegetation structure and climate. Because arthropod communities are often governed by both these factors, it can be expected that arthropod communities would fit the biomes. To test this hypothesis, we considered how well arthropod species assemblages fit South Africa's grassy biomes. Arthropod assemblages were sampled from six localities across the grassland and savanna biomes by means of suction sampling, to determine whether the two biomes have distinctive arthropod assemblages. Arthropod samples of these biomes clustered separately in multidimensional scaling analyses. Within biomes, arthropod assemblages were more distinctive for savanna localities than grassland. Arthropod samples of the two biomes clustered together when trophic groups were considered separately, suggesting some similarity in functional assemblages. Dissimilarity was greatest between biomes for phytophagous and predacious trophic groups, with most pronounced differentiation between biomes at sub-escarpment localities. Our results indicate that different arthropod assemblages do fit the grassy biomes to some extent, but the pattern is not as clear as it is for plant species.

The long-standing tradition of classifying South Africa's biogeographical area into biomes is commonly linked to vegetation structure and climate. Because arthropod communities are often governed by both these factors, it can be expected that arthropod communities would fit the biomes. To test this hypothesis, we considered how well arthropod species assemblages fit South Africa's grassy biomes. Arthropod assemblages were sampled from six localities across the grassland and savanna biomes by means of suction sampling, to determine whether the two biomes have distinctive arthropod assemblages. Arthropod samples of these biomes clustered separately in multidimensional scaling analyses. Within biomes, arthropod assemblages were more distinctive for savanna localities than grassland. Arthropod samples of the two biomes clustered together when trophic groups were considered separately, suggesting some similarity in functional assemblages. Dissimilarity was greatest between biomes for phytophagous and predacious trophic groups, with most pronounced differentiation between biomes at sub-escarpment localities. Our results indicate that different arthropod assemblages do fit the grassy biomes to some extent, but the pattern is not as clear as it is for plant species. Significance: * Provides the first comparison of arthropod composition between grassland and savanna biomes of South Africa. * Explores whether these two biomes show distinct arthropod assemblages. * Documents the characteristics of arthropod assemblages. * Confirms that plant assemblages of biomes are more distinguishable than arthropod assemblages.

Outbreaks of the blue willow beetle Phratora vulgatissima (L.) (Coleoptera: Chrysomelidae) threaten the yield of willow plantations that rely on biological control by natural enemies. Here we show that weed presence increases herbivore and predator/parasitoid diversity on willow shoots and causes increased predation on P. vulgatissima eggs compared to shoots within plots without weeds. We argue that, in addition to higher abundance, the community shift in favour of egg consumers and additive predator effects causes the higher predation pressure. This increase (~35 %) was apparent despite more alternative prey. Neither the willow genotype on which the predator–prey interaction occurred nor the clutch size affected egg predation levels. Our results support root’s enemy hypothesis and suggest that intensive weed control might counteract biological control in willow plantations. However, at least during the establishing phase of the plantation, increased biocontrol probably does not compensate for yield losses caused by competing weeds.