The herbarium of the future

Osmoxylon-like fossils from early Eocene South America: West Gondwana-Malesia connections in Araliaceae

PREMISE

Araliaceae comprise a moderately diverse, predominantly tropical angiosperm family with a limited fossil record. Gondwanan history of Araliaceae is hypothesized in the literature, but no fossils have previously been reported from the former supercontinent.

METHODS

I describe large (to macrophyll size), palmately compound-lobed leaf fossils and an isolated umbellate infructescence from the early Eocene (52 Ma), late-Gondwanan paleorainforest flora at Laguna del Hunco in Argentine Patagonia.

RESULTS

The leaf fossils are assigned to Caffapanax canessae gen. et sp. nov. (Araliaceae). Comparable living species belong to five genera that are primarily distributed from Malesia to South China. The most similar genus is Osmoxylon, which is centered in east Malesia and includes numerous threatened species. The infructescence is assigned to Davidsaralia christophae gen. et sp. nov. (Araliaceae) and is also comparable to Osmoxylon.

CONCLUSIONS

The Caffapanax leaves and Davidsaralia infructescence, potentially representing the same source taxon, are the oldest araliaceous macrofossils and provide direct evidence of Gondwanan history in the family. The new fossils and their large leaves enrich the well-established biogeographic and climatic affinities of the fossil assemblage with imperiled Indo-Pacific, everwet tropical rainforests. The fossils most likely represent shrubs or small trees, adding to the rich record of understory vegetation recovered from Laguna del Hunco.

The promise of digital herbarium specimens in large-scale phenology research

The online mobilization of herbaria has made tens of millions of specimens digitally available, revolutionizing investigations of phenology and plant responses to climate change. We identify two main themes associated with this growing body of research and highlight a selection of recent publications exemplifying: investigating phenology at large spatial and temporal scales and in understudied locations and testing long-standing theories and novel questions in ecology and evolution that were not previously answerable. We explore strengths and limitations of using digitized herbarium specimens in phenology research, including: issues of sampling; reliability, transferability, and biases; and ethical and social justice considerations. This field will see further breakthroughs as herbaria around the world continue to mobilize and digitally interlink their collections. New developments will likely come from advances in technology, international collaborations, and including understudied plant taxa and regions such as the Arctic and the tropics. Advances in technology are already improving digitization workflows and speeding the collection of phenology data from digital specimens.

Integrative Taxonomy for Species Delimitation: A Case Study in Two Widely Accepted Yet Morphologically Confounding Rosa Species Within Sect. Pimpinellifoliae (Rosaceae)

The use of morphological traits as a practical approach for delimiting taxa at various ranks has long been regarded as a reliable basis for taxonomy. However, its efficacy has been increasingly called into question in many taxonomic groups due to its inherent limitations, such as failing to account for phenotypic plasticity, ecologically driven variation (e.g., ecotypes), and parallel evolution. These factors often introduce ambiguity or misleading similarities, thereby obscuring the true evolutionary relationships among taxa, particularly in the context of species delimitation. In the present study, we employ an integrated methodology that combines quantitative morphological analyses, whole-genome data, and ecological measurements to resolve the species boundaries of two morphologically similar roses, Rosa sericea and Rosa hugonis, which have long been considered as two distinct species but lack clear morphological boundaries. Our findings reveal that the unbiased analysis of morphological data based on a large and representative sample size was insufficient to identify effective diagnostic traits. However, when complemented with genome-wide population-level sequencing data or integrated with geographic and ecological niche assessments, the delineation of species boundaries was significantly improved. Furthermore, ecological data provide additional insight into the abiotic factors driving interspecific and intraspecific divergence. By integrating multiple lines of evidence-spanning genomic (intrinsic) and phenotypic (extrinsic) traits-and incorporating the interaction between species and their environments, species boundaries can be delineated with greater confidence. A well-defined species can thus be established through the mutual corroboration of diverse datasets, thereby ensuring a more rigorous and comprehensive taxonomic framework.

Global Availability of Plant DNA Barcodes as Genomic Resources to Support Basic and Policy-Relevant Biodiversity Research

Genetic technologies such as DNA barcoding make it easier and less expensive to monitor biodiversity and its associated ecosystem services, particularly in biodiversity hotspots where traditional assessments are challenging. Successful use of these data-driven technologies, however, requires access to appropriate reference data. We reviewed the >373,584 reference plant DNA barcodes in public repositories and found that they cumulatively cover a remarkable quarter of the ~435,000 extant land plant species (Embryophyta). Nevertheless, coverage gaps in tropical biodiversity hotspots reflect well-documented biases in biodiversity science - most reference specimens originated in the Global North. Currently, at least 17% of plant families lack any reference barcode data whatsoever, affecting tropical and temperate regions alike. Investigators often emphasise the importance of marker choice and the need to ensure protocols are technically capable of detecting and identifying a broad range of taxa. Yet persistent geographic and taxonomic gaps in the reference datasets show that these protocols rely upon risk undermining all downstream applications of the strategy, ranging from basic biodiversity monitoring to policy-relevant objectives - such as the forensic authentication of materials in illegal trade. Future networks of investigators could work strategically to improve data coverage, which will be essential in global efforts to conserve biodiversity while advancing more fair and equitable access to benefits arising from genetic resources.

The digitisation workflow of the herbarium of the State Museum of Natural History of the NAS of Ukraine (LWS)

The digitisation workflow currently applied at the Herbarium of the State Museum of Natural History of the National Academy of Sciences of Ukraine (LWS) differs from other similar by cascade ('object-to-data-to-image') multilevel organisation. Its application is predicted by the need to preselect specimens by taxon and region, as well as by batched digitisation, which occurs with significant interruptions. Focusing on certain taxonomic groups from specific regions allows us to digitise specimens that could be more valuable for early scientific processing. At the same time, the herbarium benefits from such a digitisation model by revising the existing collection classification and keeping the initial ID system. The presented digitisation workflow can be easily reproduced in any herbarium with a limited budget. The purpose of this paper is to provide detailed description and schemas of the principal digitisation stages applied at the LWS Herbarium and to briefly discuss the steps crucial for a successful result. Provided information should help to maintain the digitisation and choose appropriate equipment and materials. We can conclude that, despite its general complexity, the described workflow demonstrated itself as viable and relevant due to its robust design and focus on data quality. Despite a focus on specialists' involvement, it maintains flexibility that allows combining volunteers and, if needed, outsourced efforts. Moreover, its modularity promotes independence of principal digitisation stages and allows long interruptions between the digitisation batches.

mvh: An R tool to assemble and organize virtual herbaria from openly available specimen images

Premise

Recent advances in imaging herbarium specimens have enhanced their use in biodiversity studies. However, user-friendly tools that facilitate the assembly of customized sets of herbarium specimen images on personal devices are still lacking.

Methods and Results

Here we present the R package mvh ("my virtual herbarium"), which includes functions designed to search and download metadata and openly available images associated with herbarium specimens based on taxon or geography. We tested the functionalities of mvh by searching metadata associated with five sets of 10 vascular plant species and five sets of 10 terrestrial coordinates. The download function had a success rate of 99%, downloading 291 out of the 293 images found in the search. Possible reasons for download failure are discussed.

Conclusions

As long as an internet connection is available, mvh simplifies the assembly and organization of virtual herbaria, thereby facilitating the investigation of novel empirical questions as well as trends in digitization efforts.

Guidelines for the effective and ethical sampling of herbaria

The use of herbaria for science and conservation is enabling greatly enhanced scopes and scales of discovery, exploration and protection of biodiversity. The availability of digital, open-access herbarium data is, perhaps counter-intuitively, expanding the use of physical collections by researchers who use digital collections to find specimens and then sample physical collections for multiomics investigations, including genomics, transcriptomics, metabolomics, proteomics and microbiomics. These investigations are leading to new scientific insights and supporting the development of conservation actions, but they come with a substantial cost: the partial or complete destruction of often irreplaceable specimens, which constitute a global heritage that should be permanently safeguarded for future reference. Here we provide a set of recommended best practices for the sustainable, equitable and ethical sampling of herbarium specimens. Our recommendations are intended for two complementary and partially overlapping audiences-users and stewards-who together build, use and protect herbarium collections.

Herbarium specimens reveal a cryptic invasion of polyploid Centaurea stoebe in Europe

Numerous plant species are expanding their native ranges due to anthropogenic environmental change. Because cytotypes of polyploid complexes often show similar morphologies, there may be unnoticed range expansions (i.e. cryptic invasions) of one cytotype into regions where only the other cytotype is native. We critically revised herbarium specimens of diploid and tetraploid Centaurea stoebe, collected across Europe between 1790 and 2023. Based on their distribution in natural and relict habitats and phylogeographic data, we estimated the native ranges of both cytotypes. Diploids are native across their entire European range, whereas tetraploids are native only to South-Eastern Europe and have recently expanded their range toward Central Europe. The proportion of tetraploids has exponentially increased over time in their expanded but not in their native range. This cryptic invasion predominantly occurred in ruderal habitats and enlarged the climatic niche of tetraploids toward a more oceanic climate. We conclude that spatio-temporally explicit assessments of range shifts, habitat preferences and niche evolution can improve our understanding of cryptic invasions. We also emphasize the value of herbarium specimens for accurate estimation of species´ native ranges, with fundamental implications for the design of research studies and the assessment of biodiversity trends.

Sequencing historical RNA: unrealized potential to increase understanding of the plant tree of life

Recent studies have demonstrated that it is a misconception that transcriptome sequencing requires tissue preserved at ultracold temperatures. Here, we outline the potential origins of this misconception and its possible role in biasing the geographic distribution of published plant transcriptomes. We highlight the importance of ensuring diverse sampling by providing an overview of the questions that transcriptomes can answer about the forces shaping the plant tree of life. We discuss how broadening transcriptome sequencing to include existing specimens will allow the field to grow and more fully utilize biological collections. We hope this article encourages the expansion of the current trend in 'herbariomics' research to include whole-transcriptome sequencing of historical RNA.

Leveraging OCR and HTR cloud services towards data mobilisation of historical plant names

We present our solution to the problem of how to mobilise (that is, extract and enrich) digital data from the analogue, printed book version Sir Hans Sloane's copy of John Ray's Historia Plantarum, to create the first searchable facility of its kind to the plants contained in the Sloane Herbarium, housed in the National History Museum UK. The data mobilisation workflow presented here enables the automatic detection of printed and handwritten marginalia text and annotations in Sir Hans Sloane" personal copy of John Ray's Historia Plantarum. The rationale of adopting AWS Amazon's Textract service and the development of a specialised information extraction workflow for mobilising printed text and handwritten annotations is discussed. Testing of our workflow demonstrates the need for human-checking of outputs to ensure the accuracy of a large set of structured data comprising 7600 plant names and 4540 handwritten marginalia annotation. The links we have created serve as the first digital index to Sloan's Herbarium, a unique development in the longer analogue and digital format-history of these resources.

Herbarium specimens reveal links between leaf shape of Capsella bursa-pastoris and climate

PREMISE

Studies into the evolution and development of leaf shape have connected variation in plant form, function, and fitness. For species with consistent leaf margin features, patterns in leaf architecture are related to both biotic and abiotic factors. However, for species with inconsistent leaf shapes, quantifying variation in leaf shape and the effects of environmental factors on leaf shape has proven challenging.

METHODS

To investigate leaf shape variation in a species with inconsistently shaped leaves, we used geometric morphometric modeling and deterministic techniques to analyze approximately 500 digitized specimens of Capsella bursa-pastoris collected throughout the continental United States over 100 years. We generated a morphospace of the leaf shapes and modeled leaf shape as a function of environment and time.

RESULTS

Leaf shape variation of C. bursa-pastoris was strongly associated with temperature over its growing season, with lobing decreasing as temperature increased. While we expected to see changes in variation over time, our results show that the level of leaf shape variation was consistent over the 100 years.

CONCLUSIONS

Our findings showed that species with inconsistent leaf shape variation can be quantified using geometric morphometric modeling techniques and that temperature is the main environmental factor influencing leaf shape variation.

Herbarium collections remain essential in the age of community science

The past decade has yielded more biodiversity observations from community science than the past century of traditional scientific collection. This rapid influx of data is promising for overcoming critical biodiversity data shortfalls, but we also have vast untapped resources held in undigitized natural history collections. Yet, the ability of these undigitized collections to fill data gaps, especially compared against the constant accumulation of community science data, remains unclear. Here, we compare how well community science (iNaturalist) observations and digitized herbarium specimens represent the diversity, distributions, and modeling needs of vascular plants in Canada. We find that, despite having only a third as many records, herbarium specimens capture more taxonomic, phylogenetic, and functional diversity and more efficiently capture species' environmental niches. As such, the digitization of Canada's 7.3M remaining specimens has the potential to more than quintuple our ability to model biodiversity. In contrast, it would require over 27M more iNaturalist observations to produce similar benefits. Our findings indicate that digitizing Earth's remaining herbarium specimens is likely an efficient, feasible, and potentially critical investment when it comes to improving our ability to predict and protect biodiversity into the future.

University herbaria are uniquely important

University herbaria play critical roles in biodiversity research and training and provide interdisciplinary academic environments that foster innovative uses of natural history collections. Universities have a responsibility to steward these important collections in perpetuity, in alignment with their academic missions and for the good of science and society.

AI-based discovery of habitats from museum collections

Museum collection records are a source of historic data for species occurrence, but little attention is paid to the associated descriptions of habitat at the sample locations. We propose that artificial intelligence methods have potential to use these descriptions for reconstructing past habitat, to address ecological and evolutionary questions.

Shall we promote natural history collection today?-Answered by reviewing Ernest Henry Wilson's plant collection process in China

Plant diversity exploration needs to be accelerated because many species will go extinct before their discovery and description, and many species-rich regions remain poorly studied. However, most contemporary plant collections prefer to focus on a specific group, which hinders the exploration and conservation of plant diversity. Therefore, we need an alternative approach to the dilemma at hand. The comprehensive Natural History Collection (NHC), which existed throughout the pinnacle of biodiversity exploration in the 20th century could be considered. We explore Ernest Henry Wilson's (one of the most successful naturalists in the 20th) plant collections in China as a case to illustrate the advantages of NHC and discuss whether NHC deserves to be promoted again today. From multiple sources, we gathered 19,218 available specimen records of 11,884 collecting numbers assigned and analyzed the collected species, the collection's nature, and restored four routes of his explorations. Results reveal that Wilson's specimens were collected from 28 prefecture-level cities and 38 county-level regions of 7 provinces or municipalities, they belong to 200 families, 1046 genera, 3794 species, and 342 infraspecific taxa, approximately 41 %, 22 %, 10 %, 5 % of Chinese plant families, genera, species, and infraspecific taxa respectively. The Wilson case study shows that NHC is particularly effective in emphasizing species discovery and conservation, recording ecological information, understanding a region's flora, and developing landscape applications. Therefore, we strongly advocate for the expansion of natural history collections in species-rich regions. Furthermore, we recommend the employment of specialized collectors, the enlistment of international cooperation, and the standardization of guidelines for future NHCs.

Herbarium specimens reveal links between Capsella bursa-pastoris leaf shape and climate

Studies into the evolution and development of leaf shape have connected variation in plant form, function, and fitness. For species with consistent leaf margin features, patterns in leaf architecture are related to both biotic and abiotic factors. However, for species with inconsistent leaf margin features, quantifying leaf shape variation and the effects of environmental factors on leaf shape has proven challenging. To investigate leaf shape variation in species with inconsistent shapes, we analyzed approximately 500 digitized Capsella bursa-pastoris specimens collected throughout the continental U.S. over a 100-year period with geometric morphometric modeling and deterministic techniques. We generated a morphospace of C. bursa-pastoris leaf shapes and modeled leaf shape as a function of environment and time. Our results suggest C. bursa-pastoris leaf shape variation is strongly associated with temperature over the C. bursa-pastoris growing season, with lobing decreasing as temperature increases. While we expected to see changes in variation over time, our results show that level of leaf shape variation is consistent over the 100-year period. Our findings showed that species with inconsistent leaf shape variation can be quantified using geometric morphometric modeling techniques and that temperature is the main environmental factor influencing leaf shape variation.

Expanding the Distribution of Prosthechea jauana (Orchidaceae) in the Pantepui and Highlighting the Urgent Need for Conservation Strategies in the Region in Face of Climate Change

Prosthechea jauana has been recognized as an orchid species endemic to the Venezuelan tepui. The first record of P. jauana in Brazil is presented here, also from a tepui in the Southern phytogeographical district of Pantepui in the Serra do Aracá, at the northern border of the Amazonas state. A detailed morphological description and images of the specimen are presented, as well as an updated distribution map, preliminary conservation status assessment, and taxonomic notes about the species. In addition, we provide species' distribution models for P. jauana based on current and future bioclimatic data. Future projections suggest that the geographic distribution of P. jauana will likely be severely affected, with ~79% of its suitable habitat being reduced by 2041-2060 and ~92% by 2061-2080. Prosthechea jauana could represent a flag species and an example of how climate change may affect the endemic Pantepui flora.

Data mobilisation in the LWS Herbarium: success and prospects

Background

Digitisation of hosted specimens is a crucial task for all herbaria worldwide and is one of the main streams for today. By digitising their collections and publishing the datasets, the herbaria grant access to essential data to a wide research audience and, as a result, involve their collections in scientific work more actively. Digitisation also allows virtual preservation of the collections, which is especially important in conditions of hostilities, when the entire collection can be destroyed or damaged in one moment. This paper describes two datasets recently published in GBIF in the framework of the LWS herbarium digitisation initiative. It also contains some considerations about further digitisation priorities and plans in the LWS Herbarium in the context of complicated war conditions and limited facilities.

New information

In total, 2,419 occurrence records from Ukraine mobilised from LWS Herbarium were published. These datasets are planned to be dynamic with the addition of new records along with progress of digitisation work at LWS. At least 6,000 more records are planned to be published through these datasets in 2024.

Temporal collections to study invasion biology

Biological invasions represent an extraordinary opportunity to study evolution. This is because accidental or deliberate species introductions have taken place for centuries across large geographical scales, frequently prompting rapid evolutionary transitions in invasive populations. Until recently, however, the utility of invasions as evolutionary experiments has been hampered by limited information on the makeup of populations that were part of earlier invasion stages. Now, developments in ancient and historical DNA technologies, as well as the quickening pace of digitization for millions of specimens that are housed in herbaria and museums globally, promise to help overcome this obstacle. In this review, we first introduce the types of temporal data that can be used to study invasions, highlighting the timescale captured by each approach and their respective limitations. We then discuss how ancient and historical specimens as well as data available from prior invasion studies can be used to answer questions on mechanisms of (mal)adaptation, rates of evolution, or community-level changes during invasions. By bridging the gap between contemporary and historical invasive populations, temporal data can help us connect pattern to process in invasion science. These data will become increasingly important if invasions are to achieve their full potential as experiments of evolution in nature.

Digitization of the historical Herbarium of Michele Guadagno at Pisa (PI-GUAD)

The herbarium digitization process is an essential first step in transforming the vast amount of data associated with a physical specimen into flexible digital data formats. In this framework, the Herbarium of the University of Pisa (international code PI), at the end of 2018 started a process of digitization focusing on one of its most relevant collections: the Herbarium of Michele Guadagno (1878-1930). This scholar studied flora and vegetation of different areas of southern Italy, building a large herbarium including specimens collected by himself, plus many specimens obtained through exchanges with Italian and foreign botanists. The Herbarium is composed by 547 packages of vascular plants. Metadata were entered into the online database Virtual Herbaria JACQ and mirrored into a personalized virtual Herbarium of the Botanic Museum. After the completion of the digitization process, the number of sheets preserved in the Herbarium amounts to 44,345. Besides Guadagno, who collected 42% of his specimens, a further 1,102 collectors are represented. Most specimens were collected in Europe (91%), but all the continents are represented. As expected, Italy is the most represented country (59%), followed by France, Spain, Germany, and Greece. The specimens cover a time span of 99 years, from 1830 to 1929, whereas the specimens collected by Guadagno range between 1889 and 1928. Furthermore, we traced 134 herbarium sheets associated with documents, among which 75 drawings handmade by Guadagno, 34 letters from various corresponding authors, 16 copies of publications, and 14 copies of published iconographies.

Botanical Collection Patterns and Conservation Categories of the Most Traded Timber Species from the Ecuadorian Amazon: The Role of Protected Areas

The Ecuadorian Amazon is home to a rich biodiversity of woody plant species. Nonetheless, their conservation remains difficult, as some areas remain poorly explored and lack georeferenced records. Therefore, the current study aims predominantly to analyze the collection patterns of timber species in the Amazon lowlands of Ecuador and to evaluate the conservation coverage of these species in protected areas. Furthermore, we try to determine the conservation category of the species according to the criteria of the IUCN Red List. We identified that one third of the timber species in the study area was concentrated in three provinces due to historical botanical expeditions. However, a worrying 22.0% of the species had less than five records of presence, and 29.9% had less than ten records, indicating a possible underestimation of their presence. In addition, almost half of the species evaluated were unprotected, exposing them to deforestation risks and threats. To improve knowledge and conservation of forest biodiversity in the Ecuadorian Amazon, it is recommended to perform new botanical samplings in little-explored areas and digitize data in national herbaria. It is critical to implement automated assessments of the conservation status of species with insufficient data. In addition, it is suggested to use species distribution models to identify optimal areas for forest restoration initiatives. Effective communication of results and collaboration between scientists, governments, and local communities are key to the protection and sustainable management of forest biodiversity in the Amazon region.

Harnessing herbaria to advance plant phenology research under global change

This article is a Commentary on Park et al. (2023), 239: 2153–2165.

Complex climate-mediated effects of urbanization on plant reproductive phenology and frost risk

Urbanization can affect the timing of plant reproduction (i.e. flowering and fruiting) and associated ecosystem processes. However, our knowledge of how plant phenology responds to urbanization and its associated environmental changes is limited. Herbaria represent an important, but underutilized source of data for investigating this question. We harnessed phenological data from herbarium specimens representing 200 plant species collected across 120 yr from the eastern US to investigate the spatiotemporal effects of urbanization on flowering and fruiting phenology and frost risk (i.e. time between the last frost date and flowering). Effects of urbanization on plant reproductive phenology varied significantly in direction and magnitude across species ranges. Increased urbanization led to earlier flowering in colder and wetter regions and delayed fruiting in regions with wetter spring conditions. Frost risk was elevated with increased urbanization in regions with colder and wetter spring conditions. Our study demonstrates that predictions of phenological change and its associated impacts must account for both climatic and human effects, which are context dependent and do not necessarily coincide. We must move beyond phenological models that only incorporate temperature variables and consider multiple environmental factors and their interactions when estimating plant phenology, especially at larger spatial and taxonomic scales.

The colonial legacy of herbaria

Herbarium collections shape our understanding of Earth's flora and are crucial for addressing global change issues. Their formation, however, is not free from sociopolitical issues of immediate relevance. Despite increasing efforts addressing issues of representation and colonialism in natural history collections, herbaria have received comparatively less attention. While it has been noted that the majority of plant specimens are housed in the Global North, the extent and magnitude of this disparity have not been quantified. Here we examine the colonial legacy of botanical collections, analysing 85,621,930 specimen records and assessing survey responses from 92 herbarium collections across 39 countries. We find an inverse relationship between where plant diversity exists in nature and where it is housed in herbaria. Such disparities persist across physical and digital realms despite overt colonialism ending over half a century ago. We emphasize the need for acknowledging the colonial history of herbarium collections and implementing a more equitable global paradigm for their collection, curation and use.

Herbarium specimens reveal herbivory patterns across the genus Cucurbita

PREMISE

Quantifying how closely related plant species differ in susceptibility to insect herbivory is important for understanding the variation in evolutionary pressures on plant functional traits. However, empirically measuring in situ variation in herbivory spanning the geographic range of a plant-insect complex is logistically difficult. Recently, new methods have been developed using herbarium specimens to investigate patterns in plant-insect symbioses across large geographic scales. Such investigations provide insights into how accelerated anthropogenic changes may impact plant-insect interactions that are of ecological or agricultural importance.

METHODS

Here, we analyze 274 pressed herbarium samples to investigate variation in herbivory damage in 13 different species of the economically important plant genus Cucurbita (Cucurbitaceae). This collection is composed of specimens of wild, undomesticated Cucurbita that were collected from across their native range, and Cucurbita cultivars collected from both within their native range and from locations where they have been introduced for agriculture in temperate North America.

RESULTS

Herbivory is common on individuals of all Cucurbita species collected throughout their geographic ranges. However, estimates of herbivory varied considerably among individuals, with mesophytic species accruing more insect damage than xerophytic species, and wild specimens having more herbivory than specimens collected from human-managed habitats.

CONCLUSIONS

Our study suggests that long-term evolutionary changes in habitat from xeric to mesic climates and wild to human-managed habitats may mediate the levels of herbivory pressure from coevolved herbivores. Future investigations into the potential factors that contribute to herbivory may inform the management of domesticated crop plants and their insect herbivores.