First Records of the Adventive Pseudoanthidium nanum (Mocsáry) (Hymenoptera: Megachilidae) in Illinois and Minnesota, with Notes on its Identification and Taxonomy

We report the first records of Pseudoanthidium nanum (Mocsáry) in Illinois and Minnesota in 2016 and 2018, respectively. This represents a relatively rapid expansion since P. nanum was first detected in New Jersey in 2008. In order to help monitor the spread of this bee, we provide information on how to identify P. nanum and provide images of the general habitus, diagnostic features, and male genitalia. Finally, we confirm the taxonomic identity of P. nanum in the United States and highlight potential impacts on native anthidiines

Reinstatement of Andrena vernalis Mitchell (Hymenoptera: Andrenidae) from synonymy with A. ziziae Robertson

Andrena (Micrandrena) ziziae Robertson, 1891 (Andrenidae) is a well-known species found in a variety of habitats in the eastern and central United States and adjacent southern Canada. Andrena (Micrandrena) vernalis Mitchell, 1960 was described from five female specimens in the eastern United States and was synonymized with A. ziziae by Ribble in 1968. Recently collected specimens from throughout Minnesota have revealed that A. ziziae sensu Ribble is actually two species, one of which matches A. vernalis. Here, we reinstate A. vernalis as a valid species and describe the previously unknown male. We provide diagnostic characters that separate A. ziziae and A. vernalis, as well as data on the geographic range and floral preferences of both species in Minnesota. Andrena vernalis appears to be restricted to high-quality remnant habitats, making it a species of potential conservation concern. These changes will require that previous work on A. ziziae be revisited to determine if A. vernalis is also present

First Records of the Adventive Pseudoanthidium nanum (Mocsáry) (Hymenoptera: Megachilidae) in Illinois and Minnesota, with Notes on its Identification and Taxonomy

We report the first records of Pseudoanthidium nanum (Mocsáry) in Illinois and Minnesota in 2016 and 2018, respectively. This represents a relatively rapid expansion since P. nanum was first detected in New Jersey in 2008. In order to help monitor the spread of this bee, we provide information on how to identify P. nanum and provide images of the general habitus, diagnostic features, and male genitalia. Finally, we confirm the taxonomic identity of P. nanum in the United States and highlight potential impacts on native anthidiines

Corrigendum: Delivery of crop pollination services is an insufficient argument for wild pollinator conservation

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

Wild insect diversity increases inter-annual stability in global crop pollinator communities.

While an increasing number of studies indicate that range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date, have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognising wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilising pollination services need to be considered alongside longer-term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability

Delivery of crop pollination services is an insufficient argument for wild pollinator conservation

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments

Native pollinators in anthropogenic habitats

Abstract Animals pollinate 87% of the world's flowering plant species. Therefore, how pollinators respond to human-induced land-use change has important implications for plants and the species that depend on them. Here, we synthesize the published literature on how land-use change affects the main groups of pollinators: bees, butterflies, flies, birds, and bats. Responses to land-use change are predominantly negative but are highly variable within and across taxa. The directionality of pollinator response varies according to study design, with comparisons across gradients in surrounding landscape cover finding largely negative responses and comparisons across local land-use types finding largely positive responses. Furthermore, among the studies using landscape designs, most were performed in systems where landuse change is extreme, and such studies find stronger negative effects than those performed in more moderate systems. Across multiple taxa, dietary specialists show greater sensitivity to land use than do generalists. There is a need for studies of pollinator species composition and relative abundance, rather than simply species richness and aggregate abundance, to identify the species that are lost and gained with increasing land-use change

Data from: On the inconsistency of pollinator species traits for predicting either response to land-use change or functional contribution

The response and effect trait framework, if supported empirically, would provide for powerful and general predictions about how biodiversity loss leads to loss in ecosystem function. This framework proposes that species traits will explain how different species respond to disturbance (i.e. response traits) as well as their contribution to ecosystem function (i.e. effect traits). However, predictive response and effect traits remain elusive for most systems. Here, we use data on crop pollination services provided by native, wild bees to explore the role of six commonly used species traits in determining both species' response to land-use change and the subsequent effect on crop pollination. Analyses were conducted in parallel for three crop systems (watermelon, cranberry, and blueberry) located within the same geographical region (mid-Atlantic USA). Bee species traits did not strongly predict species' response to land-use change, and the few traits that were weakly predictive were not consistent across crops. Similarly, no trait predicted species' overall functional contribution in any of the three crop systems, although body size was a good predictor of per capita efficiency in two systems. Overall we were unable to make generalizable predictions regarding species responses to land-use change and its effect on the delivery of crop pollination services. Pollinator traits may be useful for understanding ecological processes in some systems, but thus far the promise of traits-based ecology has yet to be fulfilled for pollination ecology