Xerces Society

Standardizing data collection methods is essential for advancing research, monitoring, and conservation efforts on bees. Greater consistency in data practices will enable the production of higher-quality, interoperable datasets, fostering a deeper understanding of bee populations and trends over time. This special issue series of Journal of Melittology presents six articles outlining standardized protocols and data standards to support wild bee data collection efforts, together with this article, which makes a general argument for greater standardization. These protocols are applicable to a wide range of research efforts to maximize the quality and use of wild bee occurrence data and can also be integrated into formal monitoring programs. Here, we first outline the need for, and an overview of, a series of standardized protocols and data standards developed in association with the U.S. National Native Bee Monitoring Research Coordination Network. We provide guidance on how to decide among the protocols to achieve different objectives. We then summarize key features of the protocols, including (i) how they are designed to focus on collecting only essential information, while also providing additional recommendations; (ii) that they are intended to be embedded within whatever broader sampling schemes have been designed to meet individual project or program objectives; and (iii) their emphasis on data standards. Lastly, we argue for the collection of additional ecological information that can be used to contextualize wild bee occurrence data. This information supports hypothesis testing to better understand the causal drivers underlying the status and trends of wild bees.

Human-managed green spaces in urban landscapes have become important focal points for insect conservation, partly because of the desirable insect diversity that these areas support, and also because exposure to nature is important for human health and wellbeing. An important issue in insect conservation is the extent to which non-pest insects are impacted by pesticide applications, but this has been relatively less examined outside of agricultural landscapes. Here, we investigated green spaces, including parks and private yards, in two urban areas (Sacramento, California, and Albuquerque, New Mexico), asking if larval host plants for butterflies in the two regions contained herbicides, insecticides, and fungicides. We assayed 336 individual plants in 19 genera, including woody and herbaceous plants. Pesticide presence was ubiquitous: only 22 samples had no detectable levels of pesticides; the median number of compounds detected in the other 314 individual plants was three; and the maximum detected in any one plant was 18. Within Sacramento, azoxystrobin was detected in 84% of all samples, whereas atrazine was detected in 70% of samples within Albuquerque. Two compounds (azoxystrobin and chlorantraniliprole) were found to exceed concentrations that are known to cause lethal and sublethal effects in 71 out of 336 plants. Our results suggest that the effects of pesticides on non-target species should be further explored in urban areas, and that non-target effects on desirable insects are possible in these areas without thoughtful management and elimination of non-essential pesticide applications.

Since the 1980s, monarch butterfly (Danaus plexippus plexippus) populations across North America have declined by 80%-95%. Although several studies have implicated pesticides as a contributing factor to their population declines, our understanding of monarch exposure levels in nature remains limited. In January 2024, a mass mortality event near an overwintering site in Pacific Grove, California, USA, provided an opportunity to analyze dead overwintering monarch butterflies for pesticide residues. Ten recently deceased butterflies were collected and analyzed using liquid and gas chromatography with tandem mass spectrometry. We identified 15 pesticides and associated metabolites in the butterflies, including eight insecticides (plus one associated metabolite), two herbicides (plus two associated metabolites), and two fungicides. On average, each monarch butterfly contained seven pesticides, excluding transformation products if the parent compound was also detected. Notably, three pyrethroid insecticides-bifenthrin, cypermethrin, and permethrin-were consistently detected at or near each chemical's lethal dose. Bifenthrin and cypermethrin were found in every sample, whereas permethrin was present in all but two samples. The average concentrations of these insecticides were 451.9 ng/g dry weight for bifenthrin, 646.9 ng/g dry weightfor cypermethrin, and 337.1 ng/g dry weightfor permethrin. These findings demonstrate pesticide contamination in monarch butterflies, including within urban areas, and highlight the risks pesticides, especially insecticides, pose to monarch populations. Additional measures may be required to safeguard this species from pesticide exposure, particularly near aggregation locations, such as overwintering sites in coastal California.

Pollinators are critical for food production and ecosystem function. Although native pollinators are thought to be declining, the evidence is limited. This first, taxonomically diverse assessment for mainland North America north of Mexico reveals that 22.6% (20.6 to 29.6%) of the 1,579 species in the best-studied vertebrate and insect pollinator groups have elevated risk of extinction. All three pollinating bat species are at risk and bees are the insect group most at risk (best estimate, 34.7% of 472 species assessed, range 30.3 to 43.0%). Substantial numbers of butterflies (19.5% of 632 species, range 19.1 to 21.0%) and moths (16.1% of 142 species, range 15.5 to 19.0%) are also at risk, with flower flies (14.7% of 295 species, range 11.5 to 32.9%), beetles (12.5% of 18 species, range 11.1 to 22.2%), and hummingbirds (0% of 17 species) more secure. At-risk pollinators are concentrated where diversity is highest, in the southwestern United States. Threats to pollinators vary geographically: climate change in the West and North, agriculture in the Great Plains, and pollution, agriculture, and urban development in the East. Woodland, shrubland/chaparral, and grassland habitats support the greatest numbers of at-risk pollinators. Strategies for improving pollinator habitat are increasingly available, and this study identifies species, habitats, and threats most in need of conservation actions at state, provincial, territorial, national, and continental levels.

Abstract The nesting ecology of wild bumble bees is not well resolved, but information learned from discovered nests can be of great conservation value. Data collected at nests on foraging patterns, caste‐specific behaviour and health (e.g., pathogens) are invaluable for understanding bumble bee behaviour and ecology, but difficult to decipher solely from foraging observations away from the nest. Post‐senescence nest excavation allows the estimation of colony size, caste numbers, documents pest incidence and provides opportunities to examine nest material for stressors (e.g., pesticides) and to use nest material for training purposes (e.g., conservation dogs). Wild nests are often found opportunistically, and there is an absence of standardised guidance on data collection. We provide an action plan to ensure the data collection is comparable across studies. This framework includes key conservation questions and methodological guidelines for both for in situ and post‐season nest data collection and is ordered by increasing complexity of data collection methods. To illustrate our framework, we provide an example with recently discovered Bombus affinis (rusty patched bumble bee) nests. Through observations at B. affinis nests, we discovered novel patterns of activity, changing activity levels over time, the timing of male and gyne production, variable timing in nest senescence, and associations of nests with past rodent activity. Although individual nest discoveries may be of limited value in forwarding conservation strategies, the aggregate collections of many similar datasets can be of critical importance for species of conservation concern.

IntroductionBee conservation in the US is currently hindered by challenges associated with assessing the status and trends of a diverse group of >3000 species, many of which are rare, endemic to small areas, and/or exhibit high inter-annual variationin population size. Fundamental information about the distribution of most species across space and time, thus, is lacking yet urgently needed to assess population status, guide conservation plans, and prioritize actions among species and geographies.MethodsUsing wild bee data from two public data repositories representing the contiguous US, we evaluated the availability and sufficiency of data for use in species assessments of wild bees. We also examined the number of bee species recorded in each US state and the proportion of species with recent records (2012–2021).ResultsAlthough efforts to monitor bees continue to grow, there remains a massive paucity of data. Exceedingly few records (0.04%)reported both sampling protocol and effort, greatly limiting the usefulness of the data. Few species or locations have adequate publicly available data to support analyses of population status or trends, and fewer than half of species have sufficient data to delineate geographic range. Despite an exponential increase in data submissions since the 2000s, only 47% of species were reported within the last decade, which may be driven by how data are collected, reported, and shared, or may reflect troubling patterns of local or large-scale declines and extirpations.DiscussionBased on our analysis, we provide recommendations to improve the quality and quantity of data that can be used to detect, understand, and respond to changes in wild bee populations.

What a Bee Knows: Exploring the Thoughts, Memories, and Personalities of Bees Stephen Buchmann. 2023. Washington, D.C.: Island Press. $29.99 USD E-Book, $30.00 USD Hardcover. ISBN: 9781642831245, 278 pages. Bees are widely known for their important role as efficient pollinators of flowering

Abstract Until recently, all the almond varieties grown globally, have been self-incompatible, a fact that drives the interdependent relationship between almond growers and the beekeepers that provide honey bee colonies for pollination. Recently, almond growers have begun a transition to self-fertile varieties, such as Independence, which do not require genetically distinct pollen to produce kernels. However, this transition often occurs under the impression that due to self-compatibility, one can eliminate the honey bee rentals for pollination and thereby reduce costs for these orchards, but the impact that eliminating rented colonies would have on almond quality and yield are not fully understood. Here, we explore the extent to which yields for Independence variety vary with and without honey bee pollination and across a range of hive stocking densities in the San Joaquin Valley of California. We found that access to honey bee pollination significantly improves nut set and whole tree yields, ultimately resulting in economically meaningful gains to growers. Our economic model shows how specific honey bee hive stocking density recommendations depend on the surrounding landscape and will change as acreage of self-fertile varieties continues to increase over time.

Abstract Ongoing declines in insect populations have led to substantial concern and calls for conservation action. However, even for relatively well studied groups, like butterflies, information relevant to species‐specific status and risk is scattered across field guides, the scientific literature, and agency reports. Consequently, attention and resources have been spent on a minuscule fraction of insect diversity, including a few well studied butterflies. Here we bring together heterogeneous sources of information for 396 butterfly species to provide the first regional assessment of butterflies for the 11 western US states. For 184 species, we use monitoring data to characterize historical and projected trends in population abundance. For another 212 species (for which monitoring data are not available, but other types of information can be collected), we use exposure to climate change, development, geographic range, number of host plants, and other factors to rank species for conservation concern. A phylogenetic signal is apparent, with concentrations of declining and at‐risk species in the families Lycaenidae and Hesperiidae. A geographic bias exists in that many species that lack monitoring data occur in the more southern states where we expect that impacts of warming and drying trends will be most severe. Legal protection is rare among the taxa with the highest risk values: of the top 100 species, one is listed as threatened under the US Endangered Species Act and one is a candidate for listing. Among the many taxa not currently protected, we highlight a short list of species in decline, including Vanessa annabella, Thorybes mexicanus, Euchloe ausonides, and Pholisora catullus. Notably, many of these species have broad geographic ranges, which perhaps highlights a new era of insect conservation in which small or fragmented ranges will not be the only red flags that attract conservation attention.

Abstract Many bumble bee species are declining globally from multiple threats including climate change. Identifying conservation priority areas with a changing climate will be important for conserving bumble bee species. Using systematic conservation planning, we identified priority areas for 44 bumble bee species in Canada under current and projected climates (year 2050). Conservation priority areas were identified as those that contained targeted amounts of each species predicted occurrence through climate envelope models, while minimizing the area cost of conserving the identified conservation priority areas. Conservation priority areas in the two periods were compared to established protected areas and land cover types to determine the area of current and future priority sites that are protected and the types of landscapes within priority areas. Notably, conservation priority areas were rarely within established protected areas. Priority areas were most often in croplands and grasslands, mainly within the mountain west, central and Southern Ontario, Northern Quebec, and Atlantic Canada under all climate scenarios. Conservation priority areas are predicted to increase in elevation and latitude with climate change. Our findings identify the most important regions in Canada for conserving bumble bee species under current and future climates including consistently selected future sites.