Two common bee-sampling methods reflect different assemblages of the bee (Hymenoptera: Apoidea) community in mixed-grass prairie systems and are dependent on surrounding floral resource availability

Abstract

Insect communities with diverse life histories and morphologies, such as bees (Hymenoptera: Apoidea), are difficult to representatively sample. Methodological comparison studies have increased our knowledge of bee-sampling method biases. However, further understanding of how sampling methodologies are biased with respect to functional traits and the surrounding environment is needed. We examined the differences in taxonomic and functional trait representation of sampled bee communities between an active netting and passive bee bowl methodology. We also determined the influence of surrounding floral resources on each method's ability to capture bee abundance, richness, and diversity. We captured bees at 32 sites across North Dakota, USA using both methods. Netting and bee bowl methods reflected different bee communities defined by taxonomic families, genera, diet breadth, sociality, and body size. Bee bowls reflected more solitary and small-bodied bees while the netting method selected a greater representation of generalist, social, and large-bodied taxa. Bee bowls captured fewer bees as floral abundance increased, while bee abundance, richness, and diversity captured with the netting method showed the opposite trend with increasing floral resource availability. In addition, the netting method generally captured more varied samples than bee bowl surveys. Our results indicate the importance of using multiple types of sampling methods and of understanding how surrounding floral availability affects sampling of the target bee communities. Methodological biases influence how ecological studies interpret target communities, making it essential for future bee-sampling to incorporate multiple methods and to interpret their results carefully in the context of chosen methodologies and study systems. Implications for insect conservationThe essential ecological services many bees provide, coupled with the concern over declines in bee populations and diversity, fuels the increased interest in bees and studies involving bee-sampling. Management and conservation policy for declining bee populations depend on data that is representative of the sampled bee communities. Therefore, it is important to understand systematic biases in our sampling methods as well as the effects of surrounding habitat on these biases.

Different Distribution Patterns of Hoverflies (Diptera: Syrphidae) and Bees (Hymenoptera: Anthophila) Along Altitudinal Gradients in Dolomiti Bellunesi National Park (Italy)

“…However, some criticisms have been expressed towards the use of pan traps [ 81 ]. Pan trap and active netting collections reported different assemblages of species; in addition, pan traps seem to be more efficient in the absence of floral resources, in opposition to active netting [ 82 ]. Also in the present study, some bias in hoverfly and bee sampling due to the use of pan traps may be likely.…”

Pollinator research provides conservation management implications in North Dakota

“…For butterflies, we used line‐transect distance sampling and visual encounter surveys (Antonsen et al., 2021; Kral et al., 2018a). For bees, we used floral visitor surveys and bee bowls (Bendel et al., 2019; Cutter et al., 2021; Pei et al., 2022). During each pollinator survey, observers collected data on the availability of flowering resources along belt transects (Bendel et al., 2018; Kral‐O'Brien et al., 2019).…”

“…Based on effort, we did not find any added benefits of using visual encounter surveys for butterflies, since we captured similar species with both methods, line‐transect distance sampling was easier to conduct, and distance sampling allows researchers to account for potential observer bias (Kral‐O'Brien et al., 2020; Kral‐O'Brien et al., 2021a). Gaining a better understanding of the bee community, on the other hand, relied on both methods—floral visitor surveys and bee bowls (Pei et al., 2022). Active (floral visitor surveys) and passive (bee bowls) methods are necessary due to sampling biases of both methods related to bee family, diet breadth, sociality, and body size (Pei et al., 2022; Prendergast et al., 2020; Roulston et al., 2007).…”

“…Gaining a better understanding of the bee community, on the other hand, relied on both methods—floral visitor surveys and bee bowls (Pei et al., 2022). Active (floral visitor surveys) and passive (bee bowls) methods are necessary due to sampling biases of both methods related to bee family, diet breadth, sociality, and body size (Pei et al., 2022; Prendergast et al., 2020; Roulston et al., 2007). Future studies that are interested in the most complete bee diversity would likely need multiple methods, but active surveys can be informative for floral associations and behavioral studies (Bendel et al., 2019; Popic et al., 2013).…”

“…To demonstrate the diversity of ways this relationship can form, an "x" under pollinator trait demonstrates that the pollinator community (Com), diversity (Div), or abundance (Ab) was related to the "x" for plant diversity or abundance ( Kral-O'Brien et al, 2020;Kral-O'Brien et al, 2021a). Gaining a better understanding of the bee community, on the other hand, relied on both methods-floral visitor surveys and bee bowls (Pei et al, 2022). Active (floral visitor surveys) and passive (bee bowls) methods are necessary due to sampling biases of both methods related to bee family, diet breadth, sociality, and body size (Pei et al, 2022;Prendergast et al, 2020;Roulston et al, 2007).…”