No abstract

Benchmark studies of insect populations are increasingly relevant and needed amid accelerating concern about insect trends in the Anthropocene. The growing recognition that insect populations may be in decline has given rise to a renewed call for insect population monitoring by scientists, and a desire from the broader public to participate in insect surveys. However, due to the immense diversity of insects and a vast assortment of data collection methods, there is a general lack of standardization in insect monitoring methods, such that a sudden and unplanned expansion of data collection may fail to meet its ecological potential or conservation needs without a coordinated focus on standards and best practices. To begin to address this problem, we provide simple guidelines for maximizing return on proven inventory methods that will provide insect benchmarking data suitable for a variety of ecological responses, including occurrence and distribution, phenology, abundance and biomass, and diversity and species composition. To track these responses, we present seven primary insect sampling methods—malaise trapping, light trapping, pan trapping, pitfall trappings, beating sheets, acoustic monitoring, and active visual surveys—and recommend standards while highlighting examples of model programs. For each method, we discuss key topics such as recommended spatial and temporal scales of sampling, important metadata to track, and degree of replication needed to produce rigorous estimates of ecological responses. We additionally suggest protocols for scalable insect monitoring, from backyards to national parks. Overall, we aim to compile a resource that can be used by diverse individuals and organizations seeking to initiate or improve insect monitoring programs in this era of rapid change.

One contribution of 16 to a theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.Over the past two decades, natural history collections (NHCs) have played an increasingly prominent role in global change research, but they have still greater potential, especially for the most diverse group of animals on Earth: insects. Here, we review the role of NHCs in advancing our understanding of the ecological and evolutionary responses of insects to recent global changes. Insect NHCs have helped document changes in insects' geographical distributions, phenology, phenotypic and genotypic traits over time periods up to a century. Recent work demonstrates the enormous potential of NHCs data for examining insect responses at multiple temporal, spatial and phylogenetic scales. Moving forward, insect NHCs offer unique opportunities to examine the morphological, chemical and genomic information in each specimen, thus advancing our understanding of the processes underlying species' ecological and evolutionary responses to rapid, widespread global changes.This article is part of the theme issue 'Biological collections for understanding biodiversity in the anthropocene'.

Motivation: Insects provide vital ecological functions and account for over half of all described species. An at least basic understanding of their geographical distributions is key for addressing a range of central ecological and evolutionary questions and to inform conservation. However, even for popular groups, such as butterflies, the knowledge of species' distributions at global scale remains highly incomplete. To address this information gap, we present a data product of comprehensive country-level occurrences for the 19,327 accepted species of extant butterflies. This compilation is based on a quality-controlled combination of 165 literature sources and publicly available occurrence records from Global Biodiversity Information Facility (GBIF), harmonized to a global master taxonomy, and constitutes 159,659 (87,506 unique) species-country combinations. We developed a protocol for the integration of country-level information from literature into the process of cleaning/validating species point occurrence records that facilitates dynamic updates of these country-level checklist data. Such occurrence records are available for less than 54% of the species, with an apparent bias towards temperate regions and taxa. We use this combined database for a global assessment of the geographical variation in the diversity of butterflies, including an analysis of latitudinal gradients in the species richness-the first undertaken at this higher resolution. Country-level richness decreases from the equator to the poles, both with and without control for country sizes. The presented data and analyses highlight the potential of leveraging multiple types of distribution information, particularly for taxa with limited data and their incorporation in ecological and conservation analysis. Our database and associated workflows provide a basis for an improved biogeographical understanding and conservation of insect biodiversity. Main types of variables contained:Country-level occurrences and their sources.Spatial location and grain: Global, 256 countries.

The onslaught of opportunistic data offers new opportunities to examine biodiversity patterns at large scales. However, the techniques for tracking abundance trends with such data are new and require careful consideration to ensure that variations in sampling effort do not lead to biased estimates. The analysis by Boyle et al. (2019) showing a mid-century increase in monarch abundance followed by a decrease starting in the 1960s used an inappropriate correction with respect to three dimensions of sampling effort: taxonomy, place, and time. When the data presentenced by Boyle et al. (2019) are corrected to account for biases in the collection process, the results of their analyses do not hold. The paucity of data that remain after accounting for spatial and temporal biases suggests that analyses of monarch trends back to the beginning of the 20 th are currently not possible. Continued digitization of museum records is needed to provide a firm data basis to estimate population trends.

Yucca in the American desert Southwest typically flowers in early spring, but a well-documented anomalous bloom event occurred during an unusually cold and wet late fall and early winter 2018–2019. We used community science photographs to generate flowering presence and absence data. We fit phenoclimatic models to determine which climate variables are explanatory for normal flowering, and then we tested if the same conditions that drive normal blooming also drove the anomalous blooming event. Flowering for Yucca brevifolia (Joshua tree) and Yucca schidigera (Mojave yucca) is driven by complex, nonlinear interactions between daylength, temperature, and precipitation. To our surprise, early-season flowering odds are highest in colder and drier conditions, especially for Joshua trees, but increase with precipitation late-season. However, the models used to fit normal blooming overpredicted the number of anomalous blooms compared to what was actually observed. Thus, predicting anomalous flowering events remains a challenge for quantitative phenological models. Because our model overpredicted the number of anomalous blooms, there are likely other factors, such as biotic interactions or other seasonal factors, which may be especially important in controlling what is presumed to be rare, out-of-season flowering in desert-adapted Yucca.

Zooarchaeological specimens are the remains of animals, including vertebrate and invertebrate taxa, recovered from, or in association with, archaeological contexts of deposition or surrounding landscapes. The physical scope of zooarchaeological specimens is diverse and includes macro-and micro-zooarchaeological specimens composed of archaeologically preserved bone, shell, exoskeletons, teeth, hair or fur, scales, horns or antlers, as well as geochemical (e.g., isotopes) and biochemical (e.g., ancient DNA) signatures derived from faunal remains. Artifacts and objects created from animal remains, such as bone pins, shell beads, preserved animal hides, are also zooarchaeological specimens. Here we present recent work to utilize identifiers for archaeological samples in new data publishing routines, focusing on key challenges. One critical challenge is that archaeological samples are often composited into different units depending on managers of collections and analysts. Thus, in some cases, when migrating datasets for publication, identifiers can refer to different sets of units, even within the same dataset. Another key challenge is assuring that different repositories can share sample identifiers. We show how Open Context, a site-based archaeology-focused repository that also manages objects

Phenological data (i.e., data on growth and reproductive events of organisms) are increasingly being used to study the effects of climate change, and biodiversity specimens have arisen as important sources of phenological data. However, phenological data are not expressly treated by the Darwin Core standard (Wieczorek et al. 2012), and specimen-based phenological data have been codified and stored in various Darwin Core fields using different vocabularies, making phenological data difficult to access, aggregate, and therefore analyze at scale across data sources. The California Phenology Network, an herbarium digitization collaboration launched in 2018, has harvested phenological data from over 1.4 million angiosperm specimens from California herbaria (Yost et al. 2020). We developed interim standards by which to score and store these data, but further development is needed for adoption of ideal phenological data standards into the Darwin Core. To this end, we are forming a Plant Specimen Phenology Task Group to develop a phenology extension for the Darwin Core standard. We will create fields into which phenological data can be entered and recommend a standardized vocabulary for use in these fields using the Plant Phenology Ontology (Stucky et al. 2018, Brenskelle et al. 2019). We invite all interested parties to become part of this Task Group and thereby contribute to the accesibility and use of these valuable data. In this talk, we will describe the need for plant phenological data standards, current challenges to developing such standards, and outline the next steps of the Task Group toward providing this valuable resource to the data user community.