Intraspecific Variation Research Articles

How do aboveground and belowground functional traits correlate with the demography of tree seedlings regenerated after landslide disturbances?

ABSTRACT Trait-based plant ecology is commonly used to study plant demography in forests, especially after disturbances. However, how functional traits affect the demography of regenerating seedlings after landslides remains largely unknown. This study conducted a 2-year monitoring of Abies sachalinensis (evergreen species) and Acer mono (deciduous species) seedlings dominantly regenerating in artificial landslide areas in northern Japan. We investigated the correlations between intraspecific variations in functional traits and two demographic properties (growth and mortality). We found that growth of evergreen tree seedlings was correlated with functional traits related to leaf and root construction costs and light capture capacity. However, there were no significant correlations between mortality and the functional traits for either species in the post-landslide forests. Our results emphasize the importance of both aboveground and belowground functional traits in understanding vegetation recovery after landslides. This work suggests that the intraspecific trait-demography relationships can vary depending on the demographic properties in post-landslide forests.

Leaf Spectroscopy Reveals Drought Response Variation in Fagus sylvatica Saplings From Across the Species' Range

AbstractThe common European beech (Fagus sylvatica), sensitive to prolonged drought, is expected to shift its distribution with climate change. To persist in novel environments, young trees rely on the capacity to express diverse response phenotypes. Several methods exist to study drought effects on trees and their diverse adaptive mechanisms, but these are usually destructive and challenging for the large sample numbers needed to investigate biological variation. We conducted a common garden experiment outdoors, but under controlled watering conditions, with 180 potted 2‐year‐old saplings from 16 beech provenances across the species' range, representing three distinct genetic clusters. Drought stress was simulated by interrupting irrigation and stomatal conductance and soil moisture were used to assess drought severity. We measured leaf reflectance of visible to short‐wave infrared electromagnetic radiation to determine drought‐induced changes in biochemical and structural traits derived from spectral indices and a model of leaf optical properties. We quantified changes in pigmentation, water balance, nitrogen, lignin, epicuticular wax, and leaf mass per area in drought‐treated saplings, revealing differences in likely adaptive responses to drought. F. sylvatica saplings from the Iberian Peninsula showed signatures of greater drought resistance, that is, the least drought‐induced change in spectrally derived traits related to leaf pigments and leaf water content. We demonstrate that high‐resolution leaf spectroscopy is an effective and non‐destructive tool to assess individual drought responses that can characterize functional intraspecific variation among young beech trees. Next, this approach should be scaled up to canopy‐level or airborne spectroscopy to support drought response assessments of forests.

Impacts of Artificial Light at Night (ALAN) on coastal ecosystems: A study on the herbivore Ampithoe valida with focus on sex-dependent responses.

Artificial Light at Night is recognized for its impact on various ecosystems, with coastal areas being particularly vulnerable. While a growing number of studies have identified Artificial Light at Night's impacts on species inhabiting these ecosystems, a critical gap is the limited attention that has been given to intraspecific variability in response to this stressor. This study focused on the sex-dependent influence of Artificial Light at Night on food consumption rates and absorption efficiency in males and females of the non-indigenous amphipod Ampithoe valida. Males and females were exposed to two light treatments: a natural light/dark cycle and Artificial Light at Night. Our hypothesis was that Artificial Light at Night alters the amphipod's food consumption rates and absorption efficiency, but the magnitude of these impacts is sex-dependent. Results showed that females had higher nocturnal food consumption rates under control conditions, while males showed no significant diel food consumption rates. Under Artificial Light at Night conditions, females experienced a substantial reduction in nighttime food consumption rates and absorption efficiency, suggesting stress or disrupted circadian rhythms. In contrast, males increased their nighttime food consumption rates under Artificial Light at Night, possibly exploiting a new light-induced niche. These findings highlight the need for further research on the ecological consequences of intraspecific variation in the responses to Artificial Light at Night, particularly regarding the management and conservation of ecosystems impacted by non-indigenous species.

Effects of Bti on the diversity and community composition of three Chironomidae subfamilies across different micro-habitats.

The mosquito control agent Bacillus thuringiensis subsp. israelensis (Bti) is considered environmentally friendly due to its highly specific mode of action. Nevertheless, adverse effects of Bti have been observed in non-biting midges of the family Chironomidae. In this study, we applied the maximum field rate of Bti three times from April to May to six out of twelve floodplain pond mesocosms. Chironomidae larvae were sampled two weeks after the third application in three different micro-habitats and DNA metabarcoding was used to identify the larvae. We observed Bti effects on the Chironomidae subfamily Chironominae, while Tanypodinae and Orthocladiinae remained unaffected. The interspecific diversity of Chironominae was significantly reduced by 27% in the Bti treatment. Although the interaction between treatment and habitat was not significant, a notable decrease in interspecific diversity of Chironominae between the control and Bti treatment in two out of three micro-habitats was detected (47% and 41%, respectively). We observed a significant habitat-dependent change in intraspecific diversity of Chironominae, with a 28% decline in one habitat and a 21% increase in another. The Chironominae community composition differed between the control and Bti treatment in two out of three habitats. These outcomes highlight the variability of Bti's impact on Chironomidae communities across subfamilies and micro-habitats, potentially elucidating discrepancies reported in prior studies and emphasising the necessity for comprehensive risk assessments that encompass diversity at various taxonomic levels and environmental variation at different spatial scales.

Induction by caterpillars of stored and emitted volatiles in terpene chemotypes from populations of wild cotton (Gossypium hirsutum)

BackgroundUpland cotton (Gossypium hirsutum) plants constitutively store volatile terpenes in their leaves, which are steadily emitted at low levels. Herbivory leads to a greater release of these stored volatiles. Additionally, damaged plants increase the accumulation of volatile terpenes in their leaves and begin to synthesize and emit other terpenes and additional compounds. This has been well characterised for cultivated G. hirsutum, but little is known about volatile production in response to herbivory in wild populations. We investigated how damage by a generalist herbivore species, the beet armyworm (Spodoptera exigua), affects leaf-stored and emitted volatiles in wild G. hirsutum plants and compared the responses of two known chemotypes. Wild cotton plants were grown in a greenhouse from seeds collected from four distinct locations covering sixteen populations, along the Yucatan coast (Mexico), from where this cotton species originates. We assessed whether the differences in leaf terpene profiles between the two chemotypes persisted upon herbivory, in leaves and in headspace emissions, and whether these chemotypes also differed in the production and release of herbivory-induced volatiles. In addition to chemotypic variation, we further investigated intraspecific variation in the volatile response to herbivory among genotypes, populations, and the four geographic regions.ResultsThe difference between the two chemotypes persisted after herbivory in the stored volatile profile of induced leaves, as well as in the emissions from damaged plants. Therefore, wild cotton chemotypes may differ in their airborne interactions with their environment. The specific terpenes distinguishing these chemotypes showed a weak inducibility, raising questions about their functions. Herbivory triggered changes in stored and emitted volatiles similar to what is known for cultivated varieties of G. hirsutum. However, we report for the first time on the emission of volatile aldoximes by cotton plants, which were only detected in the headspace upon herbivory, and displayed chemotypic and interpopulation variation. Intraspecific variation was also observed in the induced emissions of nitriles and certain terpenes. Moreover, chemotypes differed in their induction of (E)-β-ocimene stored in the leaves.ConclusionsThis comprehensive insight into herbivore-induced volatiles of wild cotton reveals variation in production and emission among populations. A full understanding of their ecological role may help in the development of future pest-management strategies for cotton crops.

Integrative description of two new species of the Xenylla maritima species complex (Collembola: Hypogastruridae) from Crete (Greece), with notes on the high intraspecific genetic divergence found in X. maritima Tullberg, 1869

Integrative description of two new species of the Xenylla maritima species complex (Collembola: Hypogastruridae) from Crete (Greece), with notes on the high intraspecific genetic divergence found in X. maritima Tullberg, 1869

Convergent decoupling of individual specialization and niche width during ecological release.

Trophic niche has fundamental ecological importance, but many studies consider few niche metrics and most neglect critical structuring processes. Multiple processes shape trophic niches, including inter and intra-specific competition, predation and resource diversity. These processes interact and effects vary with time and taxa. The White Sands dunefield provides an ecological gradient ideal for understanding variation in niches. We measured population niche width, trophic position and individual specialization in four lizard species across habitats over 2years. The habitats include White Sands interior, the surrounding desert scrub, and their ecotone. We used arthropod, lizard and plant stable isotopes to quantify niches. We sampled lizard competitors, predators and prey as proxies for ecological processes. We found substantial variation in niches across populations but convergence between species. Individual specialization and population niche width were surprisingly decoupled. Specialization was highest in habitats with low species diversity (White Sands) and population niche width highest at intermediate diversity (ecotone). White Sands lizards may exhibit 'ultra partitioning'; high specialization alongside low individual niche widths. Population niche width is likely constrained within White Sands by low prey diversity. High ecotonal population niche widths may be due to fewer natural enemies than desert scrub but higher resource diversity than White Sands. Trophic position and specialization were positively correlated, suggesting stronger intraspecific competition at higher trophic levels. Prey diversity, inter and intra-specific competition, and predation all interacted to shape niches. Our results highlight the need for measuring multiple components of community structure and niches, as results are likely misleading in isolation.

Energy acquisition and allocation strategies in scleractinian corals: insights from intraspecific trait variability

Energy acquisition and allocation strategies in scleractinian corals: insights from intraspecific trait variability

Functional intraspecific variation in the base water potential for seed germination along soil microclimatic gradients

Functional intraspecific variation in the base water potential for seed germination along soil microclimatic gradients

Long-term impacts of salinity and temperature changes on Brachionus calyciflorus populations: understanding the role of intraspecific variability.

Worldwide, many coastal freshwater ecosystems suffer from seawater intrusion. In addition to this stressor, it is likely that the biota inhabiting these ecosystems will also need to deal with climate change-related temperature fluctuations. The resilience of populations to long-term exposure to these stressors will depend on their genetic diversity, a key for their adaptation to changing environments. Accordingly, this study aimed to understand the long-term effects of salinity and temperature on the population density dynamics of the rotifer Brachionus calyciflorus by considering intra-specific variability. Six clonal lineages of B. calyciflorus, exhibiting differential lethal sensitivity (LC50,24h) to salinity, were exposed for at least 34days, to a control and to artificial seawater (at a conductivity corresponding to the LC70,24h for the most tolerant clonal lineage = 9.89 mS/cm), under three temperatures: 17, 20 (standard) and 23°C. Long-term exposure to artificial seawater affected population densities, leading to the extirpation of some salinity-tolerant clonal lineages earlier than that of salinity-sensitive lineages. This inversion in short- and long-term sensitivity may suggest a higher susceptibility of populations when exposed to long periods of increased salinity. The negative effects caused by artificial seawater were enhanced at 17°C and 23°C, with an even earlier occurrence of extirpation of some clonal lineages, namely, two clonal lineages considered tolerant to artificial seawater. The results suggest the potential synergistic effects of the two abiotic stressors when combined. Overall, a lack of association between the clonal lineages' short- and long-term sensitivity to salinity or their sensitivity to salinity under different temperature scenarios was observed. These results suggest an increased risk to the resilience of B. calyciflorus populations exposed to climate change-related scenarios of increased salinity and temperature fluctuations owing to an enhanced reduction in their genetic variability.

Phenotypic Variation in Cone Scales and Seeds as Drivers of Seedling Germination Dynamics of Co-Occurring Cedar and Fir Species

The intraspecific trait variations in the reproductive structures and early growth of seedlings may be critical in determining further regeneration. However, modularly built organisms, such as trees, challenge our notion of the phenotype concept, as the arrays of nonidentical homologous organs, such as seed-bearing cone scales and seeds, depending on the individual capacity to produce phenotypically variable arrangements, but they also reflect abiotic selective effects. We investigated the variability in cone scale morphology, seed traits, and germination dynamics in coexisting fir (Abies marocana) and cedar (Cedrus atlantica) trees from northern Morocco. We quantified the degree of trait overlap in two co-occurring populations of both species, as a measure of population/species functional similarity. Cone scale size and seedling growth rate were species-dependent traits, as 70%–80% of the variance was explained by the species, while only 0%–2% was explained by the population. Conversely, seed weight was a tree-dependent trait, as 70% of the variation was observed among trees, while the species only explained 20% of the variation, and the contribution of the population was negligible. Species and populations showed the same characteristics in the correlations between variables, supporting different magnitudes but a constant relationship. Substantial variations in seed weight and early seedling growth occur concurrently among cones of a single tree, independently of the tree species or population. Further studies should consider both phenotype selection and inheritance of traits’ variance on the establishment, survival, and growth of seedlings in A. marocana and C. atlantica in nurseries and reforestation sites to improve adaptive capacity to changing environmental conditions.

Scanning electron microscopy analysis of the developmental, inter‐ and intraspecific variation in the otoliths of Anguilla anguilla (Linnaeus, 1758) collected from Bafa Lake in Western Anatolia, Türkiye

AbstractThis study aimed to identify unique traits, grounded in a thorough description of the sagitta otolith of Anguilla anguilla, to characterize its ontogenetic stages between juvenile and preadult individuals. Twenty‐one characteristics were designated to investigate the ontogenetic (when comparing the otolith characteristics of fishes of different sizes, interspecific variation (comparing the otolith characteristics of the studied species with those of related species), and intraspecific variation (comparing the otolith characteristics of the studied species with those of the same species from different localities, i.e. geographical variation). This investigation concluded that the sagittal otoliths exhibited ontogenetic disparities based on the shapes recorded by different age groups. Otoliths of the young individuals belonging to fish total length groups GI and GII have shown differences in shape from those of the older individuals in the other seven length groups surveyed. An assessment of previously available otolith descriptions of A. anguilla collected from other areas revealed differences between species across larger geographic areas, making some features unsuitable for further investigation. However, other otolith traits were found to be reliable across different length groups and could be considered species‐specific features for identification. These traits include otolith width, otolith thickness, the shape of the mesial and lateral surfaces, the shape of the sulcus acusticus, the presence or absence of ostio‐caudal differentiation, and the shape, size, and thickness of the rostrum.

DNA barcoding reveals larval fish diversity and distribution along the Cibareno River (West Java, Indonesia)

Context There is a global problem with ongoing riverine infrastructure projects where, despite knowledge of potential environmental impacts, there is rapid development, often without appropriate environmental safeguards. This results in fragmentation of riverine fish communities, especially diadromous species. Understanding freshwater fish larval ecology is critical to provide insight into the likely impacts of these projects. Aims To assess fish larval biodiversity on the basis of DNA barcoding, abundance and its distribution pattern in the Cibareno River. Methods Fish larvae were collected at six locations in the Cibareno River. The larvae were identified by DNA barcoding. Key results A notable disparity was seen in the distribution of larval abundance in different locations. The non-native species, Poecilia reticulata, was the most abundant larval species, with an intraspecific diversity of 0.003 (99.7% similarity). The upstream area exhibited a lower level of larval species diversity than did the downstream area. Conclusions Genetic identification can reliably identify fish larvae and determine their spatial riverside distribution in the Cibareno River. The conservation of connectivity maintains fish community integrity and diversity between upstream and downstream locations in the weir building plan. Implications This discovery emphasises the relevance of larval identification in fish biodiversity assessment and sustainable fisheries resource monitoring.

Intraspecific Variation and Recent Loss of Ancient, Conserved Effector Genes in the Sudden Oak Death Pathogen Phytophthora ramorum.

Members of the Phytophthora genus are responsible for many important diseases in agricultural and natural ecosystems. Phytophthora ramorum causes devastating diseases of oak, and tanoak stands in US forests and larch in the UK. The four evolutionary lineages involved express different virulence phenotypes on plant hosts, and characterization of gene content is foundational to understanding the basis for these differences. Recent discovery of P. ramorum at its candidate center of origin in Asia provides a new opportunity for investigating the evolutionary history of the species. We assembled, high-quality genome sequences of six P. ramorum isolates representing three lineages from Asia and three causing epidemics in western US forests. The six genomes were assembled into 13 putative chromosomes. Analysis of structural variation revealed multiple chromosome fusion and fission events. Analysis of putative virulence genes revealed variations in effector gene composition among the sequenced lineages. We further characterized their evolutionary history and inferred a contraction of crinkler-encoding genes in the subclade of Phytophthora containing P. ramorum. There were losses of multiple families and a near complete loss of paralogs in the largest core crinkler family in the ancestor of P. ramorum and sister species P. lateralis. Secreted glycoside hydrolase enzymes showed a similar degree of variation in abundance among genomes of P. ramorum lineages as that observed among several Phytophthora species. We found plasticity among genomes from multiple lineages in a Phytophthora species and provide insights into the evolutionary history of a class of anciently conserved effector genes.

Intraspecific identification and genetic diversity analysis of Paeonia lactiflora based on chloroplast genes rpoB and psbK-psbI.

Paeonia lactiflora Pall., a member of Paeoniaceae family, is a medicinal herb widely used in traditional Chinese medicine. Chloroplasts are multifunctional organelles containing distinct genetic material. This study provides a foundation for identifying P. lactiflora, protecting and utilizing germplasm resources, and supporting molecular breeding efforts. In this study, five complete chloroplast genome sequences of P. lactiflora samples originating from different regions in China were sequenced using the Illumina NovaSeq 4000 platform. All five P. lactiflora chloroplasts had a typical cyclic tetrameric structure with 130 genes annotated. Comparative genomic analysis indicated that rpoB and psbK-psbI function as thepotential specific DNA barcodes for intraspecific identification of P. lactiflora. PCR amplification of rpoB and psbK-psbI was performed on 246 samples from 7 production areas, achieving 100% amplification efficiency. Sequence analysis revealed that 5 and 10 haplotypes were identified based on rpoB and psbK-psbI, respectively. The joint analysis of two sequences identified 15 haplotypes named Hap1 ~ Hap15. Hap5 emerged as the most prevalent and geographically widespread haplotype across China. Haplotypic diversity (Hd) was 0.786, and nucleotide diversity was 0.00281, suggesting that P. lactiflora had high genetic diversity at the species level. The Neighbor-Joining tree showed that the 15 haplotypes were clustered into two branches, indicating extensive genetic exchange between clusters. The introduction of new individuals or rare genes into different clusters through gene flow increased genetic variation within clusters, enriching P. lactiflora genetic diversity.

Genetically and chemically intraspecific variations of Ficus hirta provide novel insights into its protection and utilization

BackgroundRadix Fici Hirtae, the dry root of Ficus hirta, is a famous ethnomedicine and food that has been widely used by Yao and Zhuang nationalities in southern China for its potent antitumor, antifungal, and hepatoprotective effects. Recently, owing to over-exploitation and habitat destruction, F. hirta has been pushed to the brink of depletion. In addition, cultivation and breeding have resulted in severe intermixing and degeneration over the past 20 years. However, little is known about the genetic background and medicinal quality of F. hirta across populations, which restricts its protection and utilization. In this study, we conducted an evaluation of the chloroplast DNA (cpDNA) genetic diversity and population structure of F. hirta in southern China, and further evaluated its medicinal quality based on HPLC fingerprinting and the content determination of the active components.ResultsF. hirta presented high overall genetic diversity (Hd = 0.792) for cpDNA but low genetic diversity (Hd = 0.000 ~ 0.467) within populations. All seventeen populations were genetically assigned into two groups, most of which were not geographically clustered together. Mantel test revealed no significant isolation by distance pattern for F. hirta (P = 0.233), which might be related to its habitat fragmentation. High population differentiation (FST = 0.912) was detected in F. hirta, and AMOVA revealed that 91.17% of cpDNA variation occurred between populations. HPLC fingerprint analysis indicated that most F. hirta samples derived from 14 geographic origins had highly similar components (similarity = 0.828 ~ 0.975). Fourteen origins of F. hirta were clustered into three groups by HCA, PCA and OPLS-DA. Psoralen and bergapten were the differentiated quality markers among the groups. The medicinal quality of the populations NN, SD and HZ within southwestern group was much greater than that of the ND and GZ populations within southeastern group, which is consistent with the comprehensive quality scores for each origin (Y = 1.78 ~-0.82). The medicinal quality formation of F. hirta was highly correlated with geographical environment but not with cpDNA genetic variation.ConclusionsF. hirta presented high overall genetic diversity and population differentiation, but without significant isolation by distance, which might relate to its habitat fragmentation. Different geographic origins’ Radix Fici Hirtae were chemically clustered into three groups, which were mainly differentiated by psoralen and bergapten. The medicinal quality of Radix Fici Hirtae exhibited a southwest to southeast variation pattern across southern China, and its quality formation was influenced mostly by geographical environments. Our results provide references for the conservation, core collection construction and improvement of F. hirta.

From low to high elevations, flowers adapt traits and phenology to climate, but phenology‐trait relationships weak

Abstract Flowering phenology is central to plant reproductive success and can relate to morphological traits such as size and quality of flowers, but phenology–trait associations of flowers remain unclear. Phenology–trait associations can vary within and among species, especially across climate gradients, due to allocational trade‐offs in response to selective pressures from abiotic stress and/or biotic factors such as pollinator availability. It is unknown whether floral morphology and phenology experience coordinated selection across climate gradients or vary independently. Understanding the drivers of trait variation and its implications for floral phenology may be especially relevant in mountains where climate and abiotic gradients change sharply with elevation. At higher elevations, increasing cold and aridity may favour higher quality, stress‐tolerant flowers that withstand harsher conditions better than cheaper flowers, but trade‐off with size and showiness to pollinators. Relatively benign conditions at lower elevations may permit more flexible phenotypes and weaker association between trait and phenology by allowing species more leeway for flowering times compared with the short growing season at higher elevations. We examined trait–phenology associations within and among 250 herbaceous species in the Western Himalayas, spanning 2000–4500 m AMSL. Intraspecific variation in traits and phenology decreased from low to high elevation at the community scale, but species showed idiosyncratic responses. Trait–trait correlations indicated stronger selection and constraints on phenotypes and phenology at higher elevations. However, trait–phenology correlations were relatively weak throughout, suggesting independent selection on flower morphology vs. phenology. Overall, climate imposed strong selection on flower traits and regulated floral phenology, but without any strong or consistent associations between traits and phenology. It is likely that flower morphology responded to multiple abiotic and biotic drivers, within and across elevations, whereas phenology mainly responded to temperature and thaw. Our findings suggest that selection from ongoing warming will operate separately on floral morphology and phenology of alpine plant communities, and mechanisms and consequences should be evaluated using experiments. Read the free Plain Language Summary for this article on the Journal blog.

Limitations of 18S rDNA Sequence in Species-Level Classification of Dictyostelids

Dictyostelid species classification has traditionally relied on morphology, a time-intensive method requiring expert knowledge. This study evaluated the potential and limitations of using the 18S rDNA sequence for species-level classification. 18S rDNA sequences of 16 samples from the Dicty stock center, including 14 samples found in Thailand, were analyzed. Signature sequence analyses confirmed genus-level identification with high accuracy. These sequences were analyzed alongside 309 database entries retrieved from the GenBank database. The analyses confirmed genus-level identification accuracy but highlighted challenges in distinguishing species due to overlapping intraspecific and interspecific variations, negative barcoding gaps, and incorrectly grouped samples to putative taxa by species delimitation analyses. Species delimitation methods, including maximum likelihood (ML) phylogenetic analysis, achieved limited success, with ML showing the highest accuracy but not exceeding 50%. However, species with high barcoding gaps, such as Raperostelium and Rostrostelium, demonstrated potential for accurate classification. These findings support using 18S rDNA for genus-level identification and suggest its possible application for certain species. Expanded sampling is needed to improve species-level classification and to identify more robust DNA markers for dictyostelid diversity studies.

Intraspecific epigenomics divergence in brown bears (Ursus arctos): insights from genome-wide DNA methylation patterns

Epigenetic mechanisms such as methylation can influence gene expression and play a crucial role in the adaptation to local environmental conditions, thereby introducing non-genetic variability within species. Here, using a Reduced Representation Bisulfite Sequencing approach (RRBS), we compared the methylation patterns in blood and muscle across three European brown bear populations. Our results clearly demonstrated that, beyond tissue-driven divergences, the methylation patterns of the three populations are significantly distinct. Differentially methylated sites, possibly associated with genomic features involved in development and anatomical differentiation, are widespread across the bear genome. This finding supports previous studies suggesting a role for the alteration of developmental pathways in shaping phenotypic novelties with potential adaptative significance. Our results underscore the importance and the effectiveness of including epigenetic approaches in studying wild non-model organisms. Investigating the epigenome can be especially relevant for endangered populations that have experienced a significant erosion of genomic diversity.

Estimating body size in the large carpenter bees (<i>Xylocopa</i>)

Body size is a salient functional trait in bees, with implications for reproductive fitness, pollination ecology, and responses to environmental change. Methods for quantifying bee body size commonly rely on indirect estimates and vary widely across studies, particularly in studies of the large carpenter bees (Xylocopa Latreille) (Apidae: Xylocopinini). We evaluate the robustness of three common body size parameters (intertegular distance, head width, and costal vein length) as predictors of dry body mass within and among 11 species of Xylocopa (and 5 subspecies). We found that all three size measurements provide robust body size estimates, accounting for 92–93% of intraspecific variation in body mass. Within species, however, these measurements were considerably less predictive of body mass, explaining on average only 36.8% (intertegular distance), 57.4% (head width), and 38.8% (costal vein length) of the variation in body mass. We also highlight a novel application of photogrammetry and 3D modeling to estimate surface area and volume across species, and comment on the utility of these methods for body size estimates in Xylocopa and in insects more broadly. These findings provide practical guidelines for body size estimation methods within and among carpenter bee species.