scholarly journals Diversity of cavity-nesting bees (Hymenoptera: Apoidea) within apple orchards and wild habitats in the Annapolis Valley, Nova Scotia, Canada

2008 ◽  
Vol 140 (2) ◽  
pp. 235-249 ◽  
Author(s):  
Cory S. Sheffield ◽  
Peter G. Kevan ◽  
Sue M. Westby ◽  
Robert F. Smith
Keyword(s):  
Species Richness ◽  
Nova Scotia ◽  
Abundant Species ◽  
Apple Orchards ◽  
Natural Ecosystems ◽  
Natural Habitats ◽  
Cavity Nesting ◽  
Trap Nests ◽  
Compositional Patterns ◽  
Annapolis Valley

AbstractSolitary cavity-nesting bees, especially trap-nesting Megachilidae, have great potential as commercial pollinators. A few species have been developed for crop pollination, but the diversity, abundance, and potential pollination contributions of native cavity-nesting bees within agricultural systems have seldom been assessed. Our objectives were to compare the diversity and fecundity of cavity-nesting bees in Nova Scotia in natural ecosystems with those in apple orchards under three levels of management, using trap nests, and to determine whether any native bees show promise for development as pollinators. Our results show that species richness and numbers of bees reared from trap nests in commercially managed orchards, abandoned orchards, and natural habitats were similar, and species’ compositional patterns were not unique to specific habitats. Trap nests can be used to increase and maintain cavity-nesting bee populations within Nova Scotia apple orchards. Osmia tersula Cockerell (Megachilidae), which accounted for almost 45% of all bees captured and was the most abundant species nesting in all habitats evaluated, should be assessed for potential as a commercial pollinator of spring-flowering crops. The influence of natural cavities on bee species richness in trap-nesting surveys is also discussed.

Bee (Hymenoptera: Apoidea) diversity within apple orchards and old fields in the Annapolis Valley, Nova Scotia, Canada

2012 ◽  
Vol 145 (1) ◽  
pp. 94-114 ◽  
Author(s):  
Cory S. Sheffield ◽  
Peter G. Kevan ◽  
Alana Pindar ◽  
Laurence Packer
Keyword(s):  
Species Richness ◽  
Nova Scotia ◽  
Natural Habitat ◽  
Terrestrial Ecosystems ◽  
Old Fields ◽  
Apple Orchards ◽  
Natural Habitats ◽  
Bee Communities ◽  
Annapolis Valley ◽  
Agricultural Regions

AbstractBees are important within terrestrial ecosystems, providing pollination, which facilitates plant reproduction. Agricultural regions are large landscapes containing varying proportions of cropland, natural, and semi-natural habitats. Most bees are not restricted to any of these and move freely throughout, exploiting food and nesting resources in favourable locations. Many factors affect bee diversity, and knowledge of these is crucial for promoting healthy bee communities. The main objectives of this study were to compare diversity and guild structure of bee communities across a range of land disturbance levels within the Annapolis Valley, Nova Scotia, Canada, in habitats ranging from managed apple orchards to old fields. The two habitat extremes differed significantly; intensely managed orchards had significantly lower species richness (∼50%) than observed/estimated in old fields, but orchards with intermediate levels of adjacent natural/semi-natural habitat showed affinities to either extreme depending on the metrics used for estimating species richness. Species assemblages in orchards had lower proportions of several guilds, particularly cavity-nesters, bumble bees, and cleptoparasites, than other habitats. These guilds accounted for over 30% of bees collected in old fields but only 3–10% in orchards, increasing with habitat complexity. The use of guilds for assessing the health of bee communities is discussed.

scholarly journals Mutual and Opposing Responses of Carabid Beetles and Predatory Wasps to Local and Landscape Factors in Vineyards

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 746
Author(s):  
Deniz Uzman ◽  
Martin H. Entling ◽  
Ilona Leyer ◽  
Annette Reineke
Keyword(s):  
Species Richness ◽  
Vegetation Cover ◽  
Landscape Management ◽  
Trophic Group ◽  
Carabid Beetles ◽  
Management Options ◽  
Natural Habitats ◽  
Landscape Complexity ◽  
Biodiversity Crisis ◽  
Cavity Nesting

Preserving agro-biodiversity is one of the main means at the moment to counteract the global biodiversity crisis. Vineyard inter-rows offer vegetation covers which could function as foraging grounds for arthropods. Furthermore, organic management and enhanced landscape complexity often support biodiversity. Here, species richness and abundance of two groups of arthropod predators in vineyards were studied. Fifteen pairs of organically and conventionally managed vineyards were chosen along a gradient of landscape complexity in Rhine-Hesse, Germany. Carabid beetles were sampled using pitfall traps and cavity-nesting wasps with trap nests, respectively. Proportions of different land-use types surrounding the vineyards were calculated and inter-row vegetation cover was characterized. Species richness and abundances of both predator groups were not significantly affected by the management system. Likewise, increased cover of semi-natural habitats in the surrounding landscape did not promote their diversity or abundance. Instead, the increasing cover of annual crops diminished both groups. Cavity-nesting wasps profited from dense inter-row vegetation cover, while carabids were disadvantaged. The results indicate that distinct taxa within the same trophic group can respond oppositely to vineyard management. Thus, inter-row vegetation management with densely and sparsely vegetated elements might be best to support predator diversity. Overall, our results suggest that organic viticulture alone is insufficient to assist the studied insect groups, and that other local and landscape management options are needed for their protection.

scholarly journals Biotic stability mechanisms in Inner Mongolian grassland

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200675
Author(s):  
Yonghui Wang ◽  
Xiaxia Niu ◽  
Liqing Zhao ◽  
Cunzhu Liang ◽  
Bailing Miao ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Species Richness ◽  
Experimental Studies ◽  
Species Abundance ◽  
Abundant Species ◽  
Community Stability ◽  
Natural Ecosystems ◽  
Separate Species ◽  
Mongolian Grassland ◽  
Biotic Stability

Biotic mechanisms associated with species diversity are expected to stabilize communities in theoretical and experimental studies but may be difficult to detect in natural communities exposed to large environmental variation. We investigated biotic stability mechanisms in a multi-site study across Inner Mongolian grassland characterized by large spatial variations in species richness and composition and temporal fluctuations in precipitation. We used a new additive-partitioning method to separate species synchrony and population dynamics within communities into different species-abundance groups. Community stability was independent of species richness but was regulated by species synchrony and population dynamics, especially of abundant species. Precipitation fluctuations synchronized population dynamics within communities, reducing their stability. Our results indicate generality of biotic stability mechanisms in natural ecosystems and suggest that for accurate predictions of community stability in changing environments uneven species composition should be considered by partitioning stabilizing mechanisms into different species-abundance groups.

Comparisons of the composition of foliage-dwelling spider assemblages in apple orchards and adjacent deciduous forest

2008 ◽  
Vol 140 (3) ◽  
pp. 338-347 ◽  
Author(s):  
T.E. Sackett ◽  
C.M. Buddle ◽  
C. Vincent
Keyword(s):  
Species Richness ◽  
Deciduous Forest ◽  
Apple Orchards ◽  
Physical Disturbance ◽  
Long Distance ◽  
Natural Habitats ◽  
Spider Species ◽  
Annual Crops ◽  
Structural Disturbance ◽  
Forest Habitats

AbstractPrevious studies have shown that annual crops have different spider (Araneae) assemblages than adjacent relatively natural habitats, suggesting that spider recolonization of crops occurs via long-distance ballooning and that spider species in crops are mainly agrobionts. However, in perennial crops, e.g., apple (Malus domestica Borkhausen (Rosaceae)), which are subject to less physical disturbance than annual crops, overlap in spider species has been observed between tree foliage and adjacent habitats, suggesting that spiders colonize orchards from adjacent vegetation. The objective of this study was to compare the species composition of assemblages of foliage-dwelling spiders in apple orchards with that in adjacent deciduous forest and to determine whether spider assemblages in orchards are dominated by agrobiont species. Spiders were collected from four apple orchards and adjacent deciduous forest in southern Quebec from May until August 2004. The similarity of assemblages between the orchard and forest habitats was evaluated using nonmetric multidimensional scaling and multiresponse permutation procedures and spider species richness in the two habitat types was compared using rarefaction. Although spider species richness was higher in the forest than in the orchards, the composition of the spider assemblages in apple orchards was not significantly different from that in adjacent deciduous forest at three of the four sites. Therefore, adjacent deciduous forest, which is similar to orchards in vegetation structure and frequency of structural disturbance, is likely the main source of spiders found in apple orchards.

Control of the Apple Sucker, Psylla mali Schmidb., by the Fungus Entomophthora sphaerosperma (Fresenius)

1962 ◽  
Vol 94 (8) ◽  
pp. 818-825 ◽  
Author(s):  
R. P. Jaques ◽  
N. A. Patterson
Keyword(s):  
Nova Scotia ◽  
Low Density ◽  
Apple Orchards ◽  
General Increase ◽  
Large Numbers ◽  
Annapolis Valley

The apple sucker, Psylla mali Schmidb., was first noticed in large numbers in Nova Scotia in 1919 and within a few years populations were dense in apple orchards throughout the Annapolis Valley (Dustan, 1924a). Dustan (1924b) and Gilliatt (1924) reported that a disease caused by Entomophthora sphaerosperma (Fresenius) was prevalent among adult apple suckers during this infestation. A decline in numbers followed this early infestation due, it was thought, to the fungus. However, about the time that this early infestation declined sulphur was introduced as a fungicide. General use of sulphur continued until about 1950 and the insect was not a serious pest during this period. This association of low density of the apple sucker with the use of sulphur and the general increase in numbers of the apple sucker after the organic fungicides, ferbam, captan, glyodin, etc. became common in Nova Scotia, led to the belief that sulphur rather than E. sphaerosperma had been largely responsible for the decline of the early infestation in the 1920's.

A COMPARISON OF EPIGAEIC COLEOPTERA ASSEMBLAGES IN ORGANIC, CONVENTIONAL, AND ABANDONED ORCHARDS IN NOVA SCOTIA, CANADA

1995 ◽  
Vol 127 (5) ◽  
pp. 641-658 ◽  
Author(s):  
Isobel A. Pearsall ◽  
Sandra J. Walde
Keyword(s):  
Nova Scotia ◽  
Disease Control ◽  
Weed Control ◽  
Apple Orchards ◽  
Total Abundance ◽  
Generic Composition ◽  
Control Disease ◽  
Annapolis Valley ◽  
General Care ◽  
Organic Orchards

AbstractThe beetle fauna of conventional, organic, and abandoned apple orchards was monitored in the Annapolis Valley, Nova Scotia, between May and September 1991. Treatment in the three types of orchards differed with respect to weed control, disease control, fertilization, and general care. The most commonly captured beetles in all three types of orchards were carabids, in particular, Carabus nemoralis Müller, Carabus granulatus Linné, Harpalus rufipes (DeGeer), and Pterostichus coracinus (Newman). In general, abundance of predaceous beetles was highest in the conventional orchards and lowest in the abandoned orchards. Generic composition of predaceous beetles was similar among orchards, although the abandoned orchards were characterized by high proportions of the larger carabids, C. nemoralis and C. granulatus, whereas the organic and conventional orchards were dominated by the smaller carabids, H. rufipes and P. coracinus. Although there were no significant differences among orchard type in the total abundance of non-predaceous beetles, the abandoned orchards displayed the greatest diversity of non-predaceous beetles, with the lowest diversity found in the organic orchards.

scholarly journals The Cavity-Nesting Bee Guild (Apoidea) in a Neotropical Sandy Coastal Plain

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 706 ◽  
Author(s):  
Patricia Oliveira Rebouças ◽  
Cândida Aguiar ◽  
Vinina Ferreira ◽  
Geni Sodré ◽  
Carlos Carvalho ◽  
...  
Keyword(s):  
Abundant Species ◽  
Similar Rate ◽  
Artificial Substrates ◽  
Cultivated Plants ◽  
Offspring Sex Ratio ◽  
Cavity Nesting ◽  
Trap Nests ◽  
Nesting Sites ◽  
Nesting Activity ◽  
Offspring Mortality

Some solitary bees establish their nests in preexisting cavities. Such nesting behavior facilitates the investigation of their life history, as well as the monitoring of their populations in natural, semi-natural and cropped habitats. This study aimed to evaluate the acceptance of artificial substrates by cavity-nesting bees in a heterogeneous landscape. We investigated the percentage of occupation of the different trap-nests, the monthly fluctuations in the nesting activity, offspring sex ratio, mortality and parasitism, in two phytophysiognomies: herbaceous-shrub restinga (site 1) and arboreal restinga (site 2). We used as trap-nests, bamboo canes, large and small straws of cardboard inserted into solid wooden blocks. Five bee species established 193 nests, from which 386 adults emerged. Centris tarsata Smith was the most abundant species. Large straws were signifi cantly more occupied than small straws (χ² = 19.951; df = 1; p < 0.0001). Offspring mortality rate for unknown reasons was signifi cant diff erent between sites, 11% (site 1) and 20% (site 2) (χ² = 4.203; df = 1; p = 0.04). The cavity-nesting bee guild had similar composition in both phytophysiognomies, there was a similar rate of occupation of trap-nests in both sites, as well as dominance of C. tarsata nests. Offspring mortality and parasites attack rates seem to be the more distinctive aspects between the herbaceous shrub and arboreal restinga sampled. Our study indicated that remnant fragments of coastal native habitats may be important nesting sites for the maintenance of bee populations, some of which have been indicated as candidates for management as pollinators of cultivated plants in Brazil.

scholarly journals Pollinator enhancement in agriculture: comparing sown flower strips, hedges and sown hedge herb layers in apple orchards

2021 ◽  
Author(s):  
Vivien von Königslöw ◽  
Felix Fornoff ◽  
Alexandra-Maria Klein
Keyword(s):  
Species Richness ◽  
Agricultural Landscapes ◽  
Floral Resources ◽  
Apple Orchards ◽  
Wild Bees ◽  
Natural Habitats ◽  
Flower Visitation ◽  
Wild Bee ◽  
Pollinator Community ◽  
Main Driver

AbstractIn intensive agricultural landscapes semi-natural habitats for pollinators are often limited, although willingness to establish pollinator habitat is increasing among farmers. A common pollinator enhancement measure is to provide flower strips, but existent or improved hedgerows might be more effective. In this study, we compare the effectiveness of three pollinator enhancement measures at edges of conventional apple orchards: (i) perennial flower strips, (ii) existent hedgerows, and (iii) existent hedgerows complemented with a sown herb layer. We used orchard edges without any enhancement as control. The study took place over three consecutive years in Southern Germany. Wild bee abundance and species richness were highest in flower strips followed by improved hedges. Hoverflies were also most abundant in flower strips, but not more species rich than at control sites. Wild bee but not hoverfly community composition differed between control and enhancement sites. The overall pollinator community included only few threatened or specialized species. Flower abundance was the main driver for wild bee diversity, whereas hoverflies were largely unaffected by floral resources. Pollinator enhancement had neither an effect on the abundance or species richness within the orchards nor on apple flower visitation. Perennial flower strips seem most effective to enhance wild bees in intensive agricultural landscapes. Additionally, flower-rich hedgerows should be promoted to complement flower strips by extending the flowering period and to increase connectivity of pollinator habitat in agricultural landscapes.

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