Small Beetle Research Articles

Niche overlap with an exotic competitor mediates the abundant niche‐centre relationship for a native lady beetle

AbstractAimThe abundant niche‐centre hypothesis has been used to describe patterns of species abundance relative to position in ecological niche space. Such relationships, however, are inconsistently recovered and may be obscured due to non‐equilibrium distributions, such as those caused novel interactions with exotic species. Here, we explore patterns of fitness for the nine‐spotted lady (Coccinella novemnotata) following the introduction of an exotic competitor, the seven‐spotted lady beetle (C. septempunctata). We examine how niche overlap between species may be causing a range reduction for C. novemnotata through a modified abundant niche‐centre relationship.LocationNorth America.MethodsWe applied a time‐oriented view of the abundant niche‐centre relationship for C. novemnotata, both before and after the introduction of C. septempunctata. We tested for both niche overlap and correlation between C. novemnotata body size (i.e. fitness) and the distance from its niche centroid relative to the invasion status of C. septempunctata.ResultsThe current niche space currently occupied by C. novemnotata is equivalent to its historic niche but has shifted to avoid overlap with C. septempunctata. A historic abundant niche‐centre relationship with larger individuals closer to the niche centroid was observed for C. novemnotata. However, this pattern changed to have smaller beetles near the niche centroid when the current distribution was considered.Main ConclusionsFitness patterns displayed by C. novemnotata are effectively described by the abundant niche‐centre hypothesis. However, this relationship was modified with the introduction of C. septempunctata. Coccinella novemnotata is not excluded from previously suitable areas that correspond to niche space nearest to its niche centroid. Abundant niche‐centre relationships may provide strong predictions of species' fitness across a species geographic range; however, these relationships may be obscured by novel pressures resulting in non‐equilibrium states.

Species Occurrence of Weevils in the Northern Part of Mt. Malindang Range Natural Park, Philippines

Weevils are small beetles with long, narrow snouts which is a characteristic of insects belonging to the Curculionidae family. A study on the species composition of weevils was conducted in the northern part of Mt. Malindang Range Natural Park last February 2023. Field investigations were done using a combination of transect walk and opportunistic sampling. A total of 195 individuals of weevils were recorded, comprising seventeen (17) species belonging to two (2) genera- Metapocyrtus and Alcidodes . Metapocyrtus malindangensis was observed in all sampling sites. Site 1 (Gandawan) had the highest species richness (N=13), and the highest species diversity (H’=2.016) was recorded in Site 2 (Lake Duminagat). Cluster analysis showed that weevil species in Lake Duminagat and Uluhan sa Dapitan have closer similarities. The study also recorded unidentified specimens that are potentially new to science. It is highly recommended that more explorations should be conducted to record the species occurrence of weevils in other parts of Mt. Malindang. Keywords : Curculionidae, endemic, Metapocyrtus, opportunisti

A Comparative Analysis of Age-Stage Two Sex Life Tables in Distinct Forms of Callosobruchus maculatus (F.): Insights into Population Dynamics and Reproductive Strategies

Callosobruchus maculatus, the bean weevil, is a fascinating insect that showcases remarkable adaptations for survival. Found in tropical and subtropical regions, it has become a global pest due to its adaptability and hitchhiking capabilities, causing substantial grain losses. This small beetle, part of the Chrysomelidae family, serves as a valuable model organism in entomology and agricultural research. One of the key aspects of Callosobruchus maculatus that captures the attention of scientists is its dichotomy between active and inactive forms. These two forms represent distinct survival strategies employed by the beetle to navigate its ever-changing environment. The present study provides a comprehensive overview of the study on Callosobruchus maculatus, highlighting the two distinct forms of the species, their adaptations, and the significance of understanding their lifetable parameters. It emphasizes the ecological, practical, and research-oriented implications of this study, ranging from ecological insights to pest management strategies and the optimization of mass multiplication protocols. These forms exhibited notable differences in various life history parameters and survival characteristics. Flightless-inactive females had longer preoviposition and oviposition period and laid a significantly higher average of eggs per female with higher reproduction potential. Female fecundity (eggs/female) was much lower in the flight-active form (18.6) than in the flightless-inactive form (84.10) and maintained constant survival rate. Life expectancy values were generally lower for the flightless-inactive form compared to the flight-active form across different stages and sexes. Both males and females in the flight-active form exhibited a consistent and relatively high life expectancy, with a 100% chance of survival throughout all age intervals. Overall, these findings provide a comprehensive understanding of the differences in life history traits, reproductive strategies, and survival patterns between the flight-active and flightless-inactive forms of Callosobruchus beetles in a controlled laboratory environment.

Calibrating insect age at eclosion by size in a gregarious carrion beetle Thanatophilus sinuatus (Staphylinidae: Silphinae).

Recent discoveries have shown that the physiological age at eclosion of forensically useful beetles differs between males and females and between beetles of various sizes. Accordingly, it was postulated that the size and sex of the beetles at eclosion may be used to calibrate their age, which may improve the accuracy of age (and post-mortem interval) estimates in forensic entomology. In this study, we derived thermal summation models for the eclosion for the Central European population of carrion beetles Thanatophilus sinuatus (Fabricius, 1775), (Staphylinidae: Silphinae), and tested the usefulness of sex and size for the calibration of beetle age at eclosion. Although in previous developmental studies, the beetles were reared individually, we reared them in larval aggregations, since in natural conditions T. sinuatus beetles are gregarious. Weak (r2 between 5% and 13%) negative correlations were observed between the size and age of T. sinuatus males or females at eclosion, demonstrating that calibration of age by beetle size and sex may bring only minimal benefits regarding the accuracy of age estimation in this species. However, it may still be worthwhile in the case of extremely large or small beetles. Moreover, the total development times recorded in this study were much shorter than in the previous T. sinuatus study, at 14°C by about 15 days and at 26°C by about 2 days. These differences emphasise the importance of gregariousness for the development of carrion beetles, and at the same time highlight the need for the ecologically-relevant protocols of development studies in forensic entomology.

A new species of Cerylonidae (Insecta: Coleoptera) described from Baltic amber using X-Ray microtomography

ABSTRACT Examples of the small beetle family Cerylonidae are scarcely represented in the fossil record or at least are rarely determined as such by specialists. Until now, only one species of an extinct genus has been reliably identified to this family from Eocene Baltic amber. A new species, Mychocerus gedanensis McHugh et Ślipiński, sp. nov. (Coleoptera, Cerylonidae), is described from Eocene Baltic amber using X-ray micro-computed tomography (μCT) and optical microscopy. This is the first extinct species described for the subfamily Ceryloninae. It belongs to the extant genus Mychocerus Erichson, 1845, the largest cerylonid genus, which has a widespread distribution that until now excluded the continental parts of the Palaearctic. The new fossil species can be placed in the North American discretus group with two remarkably similar species (M. discretus (Casey, 1890) and M. striatus Sen Gupta & Crowson, 1973) based on the presence of a long and parallel-sided prosternal process. LSID: urn:lsid:zoobank.org:act:95EA100C-3323-472C-A17B-B75480B3FB18

Biodiversity in landscape mosaics: The roles of local land use and the surrounding landscape on dung beetle assemblages

Abstract Biotic communities in heterogeneous agricultural landscapes can be shaped by both the land use of local patches and the structure of surrounding landscapes. However, studies usually focus on one or the other factor, limiting our ability to propose management guidelines for the conservation of biodiversity in human‐modified landscapes. We used a site‐landscape design and multi‐model inference to assess the effects of land use, landscape structure, and their interactions, on dung beetle assemblages in agricultural landscapes in the Brazilian Cerrado, a biodiversity hotspot. We captured dung beetles in five dominant land uses (savanna, forest, eucalypt, cattle pasture and soybean) and estimated species density, abundance of large and small beetles, and functional richness and dispersion. We measured four landscape structure predictors (savanna cover, forest cover, landscape compositional heterogeneity, and matrix harshness) in circular landscapes around sampling plots. All response variables were affected by land use and by at least one landscape predictor. Relationships between landscape predictors and dung beetle responses were as expected (positive for forest and savanna covers and negative for matrix harshness), except landscape compositional heterogeneity, which had unexpected negative effects. More importantly, land use and landscape predictors interacted in two cases: higher forest cover and lower matrix harshness were related to higher species density and large‐beetle abundance, respectively, but this was mainly observed in eucalypt. Synthesis and applications: To better guide the conservation of mobile organisms in anthropogenic habitat mosaics, we need to consider both landscape characteristics and the land use of local patches. Using this approach, we are able to make some recommendations for the conservation of dung beetles in agricultural landscapes in Cerrado, including the following: (i) ensure, through protection and/or restoration, that natural vegetation patches (even small ones) are interspersed in the agricultural matrix, to increase functional diversity in all land uses and taxonomic diversity in tree plantations, (ii) place eucalypt plantations near forest patches to increase the abundance of sensitive species (forest‐specialists, and some large species); (iii) replace some patches of pasture or soybean with tree plantations, to increase the amount of supplementary habitat for sensitive species.

Climate Change Impacts on the Potential Distribution Pattern of Osphya (Coleoptera: Melandryidae), an Old but Small Beetle Group Distributed in the Northern Hemisphere.

Exploring the development of species distribution patterns under climate change is the basis of biogeography and macroecology. However, under the background of global climate change, few studies focus on how the distribution pattern and the range of insects have or will change in response to long-term climate change. An old but small, Northern-Hemisphere-distributed beetle group Osphya is an ideal subject to conduct the study in this aspect. Here, based on a comprehensive geographic dataset, we analyzed the global distribution pattern of Osphya using ArcGIS techniques, which declared a discontinuous and uneven distribution pattern across the USA, Europe, and Asia. Furthermore, we predicted the suitable habitats of Osphya under different climate scenarios via the MaxEnt model. The results showed that the high suitability areas were always concentrated in the European Mediterranean and the western coast of USA, while a low suitability exhibited in Asia. Moreover, by integrating the analyses of biogeography and habitat suitability, we inferred that the Osphya species conservatively prefer a warm, stable, and rainy climate, and they tend to expand towards higher latitude in response to the climate warming from the past to future. These results are helpful in exploring the species diversity and protection of Osphya.

Disentangling thermal from alternative drivers of reflectance in jewel beetles: A macroecological study

AbstractAimTo predict future colour–climate relationships, it is important to distinguish thermal drivers of reflectance from other evolutionary drivers. We aimed to achieve this by comparing relationships between climate and coloration in ultraviolet–visible (UV–Vis) and near‐infrared (NIR) light, separately.LocationSamples were distributed primarily across Australia and North America, with some from Africa and Asia.Major taxa studiedColeoptera: Buprestidae.MethodsWe used jewel beetles as models to identify climatic drivers of reflectance, because jewel beetles have highly diverse coloration and a wide distribution and are often active in hot conditions. Specifically, we tested the association between climate, body size and reflectance using a phylogenetic comparative analysis for three wavebands (UV–Vis, NIR and total).ResultsReflectance of jewel beetles was more strongly predicted by body size than by climate. NIR reflectance and total reflectance were not associated with climate, but larger beetles had higher NIR reflectance. For UV–Vis reflectance, small beetles were darker in warmer and more humid environments, whereas there was no association with climate for large beetles.Main conclusionsOur study suggests that variation in reflectance of jewel beetles is not driven by thermal requirements and highlights the importance of considering NIR reflectance when evaluating explanations of the effects of colour on thermoregulation.

Rhagophthalmidae Olivier, 1907 (Coleoptera, Elateroidea): described genera and species, current problems, and prospects for the bioluminescent and paedomorphic beetle lineage.

Rhagophthalmidae are a small beetle family known from the eastern Palaearctic and Oriental realms. Rhagophthalmidae are closely related to railroad worms (Phengodidae) and fireflies (Lampyridae) with which they share highly modified paedomorphic females and the ability to emit light. Currently, Rhagophthalmidae include 66 species classified in the following 12 genera: Bicladodrilus Pic, 1921 (two spp.), Bicladum Pic, 1921 (two spp.), Dioptoma Pascoe, 1860 (two spp.), Diplocladon Gorham, 1883 (two spp.), Dodecatoma Westwood, 1849 (eight spp.), Falsophrixothrix Pic, 1937 (six spp.), Haplocladon Gorham, 1883 (two spp.), Menghuoius Kawashima, 2000 (three spp.), Mimoochotyra Pic, 1937 (one sp.), Monodrilus Pic, 1921 (two spp. in two subgenera), Pseudothilmanus Pic, 1918 (two spp.), and Rhagophthalmus Motschulsky, 1854 (34 spp.). The replacement name Haplocladongorhami Kundrata, nom. nov. is proposed for Diplocladonhasseltii Gorham, 1883b (described in subgenus Haplocladon) which is preoccupied by Diplocladonhasseltii Gorham, 1883a. The genus Reductodrilus Pic, 1943 is tentatively placed in Lampyridae: Ototretinae. Lectotypes are designated for Pseudothilmanusalatus Pic, 1918 and P.marginalis Pic, 1918. Interestingly, in the eastern part of their distribution, Rhagophthalmidae have remained within the boundaries of the Sunda Shelf and the Philippines demarcated by the Wallace Line, which separates the Oriental and Australasian realms. This study is intended to be a first step towards a comprehensive revision of the group on both genus and species levels. Additionally, critical problems and prospects for rhagophthalmid research are briefly discussed.

Structure of the Brain of the Smallest Coleoptera

The structure of the brain of the smallest coleopteran, Scydosella musawasensis Hall, 1999, is described for the first time. As in other extremely small beetles, the brain of S. musawasensis displays signs of miniaturization: displacement to the thorax, compactization, and a small number and size of the neurons. The body size of the studied smallest beetle is similar to that of the minute hymenopteran Megaphragma, which has a nearly anucleate nervous system. However, the structure of the brain of the studied smallest beetle is similar to that of large representatives of the order and is characterized by a high number of nuclei in the brain and a significant volume of the cell body rind. The neuropil of S. musawasensis occupies 60% of the brain volume, confirming the neuropilar constant rule.

A small beetle larva preserved in 23-million-year-old Mexican amber: possible first fossil record of an immature variegated mud-loving beetle

Beetles occupy a vast amount of different ecological roles in both terrestrial and freshwater ecosystems. The often very specialised morphology of the adults can frequently be associated with their specific roles. Yet, the ecologically independent larvae of the same species are often unknown; this applies even more so to fossils. Here we report a new fossil beetle larva preserved in Mexican amber. The beetle larva was documented via digital microscopy and X-ray micro-computed tomography (X-ray µCT). The observed features, especially of the trunk, but also the maxillo-labial complex as well as the moulting suture of the head capsule are reminiscent to those of larvae of variegated mud-loving beetles, Heteroceridae. The trunk end is tube-like and protrudes ventro-terminally from abdomen segment 9. While present in other beetle lineages, this morphology is in these lineages, for example, not combined with a simple moulting suture. Some features potentially further supporting an interpretation as a larva of Heteroceridae are not accessible. The interpretation yet remains the most compatible one. Assuming a similar life style to modern larvae of Heteroceridae indicates an original lifestyle associated with running waters, but not within these. Heteroceridae is an ingroup of Byrrhoidea; the fossil record of byrrhoidean larvae is still very scarce. The new fossil hence adds a rare ecological function to the Miocene amber fauna, representing the first fossil record of a larva of Heteroceridae and expanding the fossil record of byrrhoidean larvae.

Outbreak of Pityogenes chalcographus and Pityophthorus pityographus on Spruce Seedlings Resulting from Inappropriate Management in a Forest Nursery

In this report, we describe a local outbreak of small bark beetles on 4-year-old seedlings of Picea abies in a forest nursery in Central Europe in 2021. In March 2022, 10–50% of the seedlings were “dry” (i.e., with dry and easily broken twigs and with easily peeled bark) in each 4-row bed in the nursery. Half of the dry plants were completely covered by galleries of bark beetles and another 35% of the seedlings were with one or two bark beetle galleries. Almost 90% of the beetles found on the affected seedlings were Pityogenes chalcographus, and only 10% were Pityophthorus pityographus (we studied 100 seedlings in the second bed). The chipping of Picea pungens in previous years had left many felled trunks, branches, and other logging residues in the area. These residues are covered by galleries of both bark beetles. We suggest that, after multiplying on the logging residues, the beetles could not find suitable material for reproduction and were lured to the nursery seedlings, which had been weakened by location (a location that provided inadequate shade and no wind protection) and by repeated replanting.

Distribution of the Small Spruce Bark Beetle Ips amitinus (Eichhoff, 1872) in Western Siberia

Distribution of the Small Spruce Bark Beetle Ips amitinus (Eichhoff, 1872) in Western Siberia

Activity patterns of Cybotus estriatus (LeConte, 1878) (Coleoptera: Tenebrionidae) on a Caribbean beach

Sandy beach ecosystems are extreme environments in which darkling beetles (Tenebrionidae) have been usually reported as a dominant component of the fauna. The abundance and richness of tenebrionids in arid zones is facilitated by specific physiological, morphological, and behavioural traits, such as limited activity patterns or the use of suitable microhabitats. Activity patterns of tenebrionid beetles have been investigated mainly in large-size species, but the response of small species remains basically unknown. Considering this, we developed a study in a Caribbean beach in Costa Rica with the aim of identifying daily activity patterns of Cybotus estriatus (LeConte, 1878), a darkling beetle of 2–3 mm in length relatively frequent in the circum-Caribbean beaches. In addition, we assessed how vegetation cover influences the abundance of this small tenebrionid species. Observations were performed between 7:00 h to 18:30 h, within a range of temperatures from 28°C to 47°C. Cybotus estriatus exhibits a bimodal activity pattern similar to those observed for other tenebrionids. It remains active at a temperature range of 35°C to 44°C, but shows a higher activity around 10:00 h and 15:30 h, at temperatures between 38°C and 42°C. We also found a strong dependence of C. estriatus on beach vegetation, providing the first data on the effect of vegetation cover in small tropical beetles inhabiting sand beaches. Our results suggest that body size may not be the critical factor determining activity in tenebrionids, and that preserving the natural vegetation in sandy beaches is essential to maintain the biodiversity of these ecosystems.

Diversity of Insect Flower Visitors of Xylopia aromatica (Magnoliales, Annonaceae) in a Brazilian Savanna

Small beetles are important pollinators of Annonaceae whose flower chambers are small and have diurnal and/or nocturnal anthesis. The pollinators of these flowers belong to the families Nitidulidae, Staphylinidae, Chrysomelidae, and Curculionidae. In this study, the first conducted in the Cerrado of Chapada dos Guimarães, Mato Grosso, Brazil, the behavior of the insect flower visitors of Xylopia aromatica was observed, in both the field and the laboratory. The chambers of 253 flowers were collected from 11 plants, and the biological aspects of their visitors were analyzed quantitatively and qualitatively. The most abundant visitors were thrips and beetles. Coleoptera was represented by four morphospecies occurring frequently in the floral chambers (>70% of individuals). Among beetles, one species belonged to Nitidulidae (Cillaeinae, Conotelus sp. 1) and two belonged to Staphylinidae (Aleocharinae sp. 1 and Aleocharinae sp. 2). These three morphospecies of small elongate beetles have setae where pollen may adhere. In addition, they were present on both male and female phases of the flowers, indicating potential cross-pollination. In the study area, X. aromatica possesses mixed pollination promoted by Thysanoptera and small Nitidulidae and Staphylinidae beetles. This study brings the first record of Lamprosomatinae (Chrysomelidae) and, especially, of Conotelus (Nitidulidae) in the flower chambers of X. aromatica, with new information on behavior of floral visitors coupled with their morphological traits that may promote cross-pollination in this plant species.

Differential Attraction of Large and Small Tunneling Dung Beetles (Coleoptera: Geotrupidae and Scarabaeidae) to Native Mammal Dung in a Satoyama Forest in Central Japan

Differential Attraction of Large and Small Tunneling Dung Beetles (Coleoptera: Geotrupidae and Scarabaeidae) to Native Mammal Dung in a Satoyama Forest in Central Japan

Floral Resources Enhance Fecundity, but Not Flight Activity, in a Specialized Aphid Predator, Hippodamia convergens (Coleoptera: Coccinellidae)

Adult aphid predators disperse across the landscape seasonally in search of prey aggregations that are patchily distributed and temporally variable. However, flight is energetically costly and consumes resources that could be invested in reproduction. Hippodamia convergens is an important aphid predator in North American cereal crops and other agricultural systems. Consumption of floral resources can enhance adult survival during periods of low prey availability and may improve reproductive success. We tested how an omnivorous adult diet containing floral resources (diluted honey and pulverized bee pollen) interacts with body size to influence reproduction and flight behavior compared to a prey-only diet. Two sizes of beetles were produced by controlling larval access to food—3 h daily access produced small beetles; ad libitum access produced large beetles with faster development. Reproductive performance was tracked for 18 days, and female flight activity was assayed via 3 h bouts of tethered flight. Diet composition and body size interacted to influence preoviposition period, with large females in prey-only treatments delaying oviposition the longest. The omnivorous adult diet improved 18-day fecundity relative to a prey-only diet, but egg fertility was unaffected. Adult size affected oviposition pattern, with small beetles laying smaller, but more numerous, clutches. Females flew up to 7 km in 6 h, but neither body size nor adult diet influenced flight distance, suggesting that all diet treatments generated energy reserves sufficient to power flights of short duration. However, pre-reproductive females flew > 60% further than they did post-reproduction, likely due to the energetic costs of oviposition. Thus, access to pollen and nectar increased reproductive success and altered oviposition patterns in H. convergens, indicating the importance of floral resources in the agricultural landscape to conservation of this predator and its biological control services.

Coleopteran Pollinators of Annonaceae in the Brazilian Cerrado—A Review

The evolutionary trajectories of insects and angiosperms appear to be intimately interconnected. Increases in the diversity of phytophagous beetles and angiosperms co-occur in the Mesozoic fossil record, and there is fossil evidence of pollinivory and pollination by insects, both in flowering plants and in gymnosperms. The oldest records of angiosperm pollination indicate flies as pollen vectors. A basal group of angiosperms, the order Magnoliales, has retained plesiomorphic characters such as dozens of pistils and stamens spiraling around the receptacle. In a family of this order, Annonaceae, over 90% of species are pollinated by beetles. In many Annonaceae species, flowers display wide spaces, referred to as floral chambers, where beetles can find shelter from weather conditions and predators, food in the form of pollen and tissues, and a mating site. Two basic types of floral chambers can be distinguished: small chambers visited by small beetles (Nitidulidae, Staphylinidae, Chrysomelidae, and Curculionidae) with diurnal and/or nocturnal activity and large and thermogenic floral chambers visited by beetles of the tribe Cyclocephalini (Scarabaeoidea, Melolonthidae). In the latter case, the heat that the flowers produce may serve as a resource for the beetles that visit them, resulting in smaller endothermy costs for the scarabs. This study reviewed the literature including PhD and MSc theses on cantharophilous Annonaceae in the Cerrado. In this biome, both types of associations are found, although cantharophilous Annonaceae represent a small portion of the plant species (<5%). Cantharophilous Annonaceae in the Cerrado share attributes according to the beetles that pollinate them: species pollinated by small beetles, for instance, may flower throughout the year, whereas Annonaceae pollinated by Cyclocephalini normally flower in the beginning of the rainy season (October/November), in synchrony with the phenological patterns of their pollinators. Cantharophilous Annonaceae flowers, regardless of their size, tend to have light colors and sweet and fruity odors. In addition to the lack of studies on the attraction of beetles by these floral characters, the taxonomic composition of the beetles that pollinate Annonaceae in the Cerrado is poorly known. This review attempts to discuss, in light of what has already been published, potential fields of investigation concerning pollinating beetles’ behavior and evolution.

Two new genera and three new species of cavernicolous trechines from the western Wuling Mountains, China (Coleoptera, Carabidae, Trechinae).

Two new genera and three new species of cave-adapted ground beetles belonging to the tribe Trechini are established and described: Wulongiusqilingergen. nov. and sp. nov. from limestone cave Qiankou Dong (Chongqing: Wulong), Qianotrechuscongcongaesp. nov. from cave Shigao Dong (Chongqing: Nanchuan), and Qianlongiuszhouigen. nov. and sp. nov. from cave Qianlong Dong (Guizhou: Songtao). Wulongiusqilingersp. nov. is a small aphaenopsian beetle with a thin and elongated body, while Qianlongiuszhouisp. nov. is a semi-aphaenopsian with a stout body. Both new genera are not closely related to any genus of Trechini occurring in the South China Karst, and so their systematic positions remain unclear.

Concerted evolution of body mass, cell size and metabolic rate among carabid beetles

Alterations in cell number and size are apparently associated with the body mass differences between species and sexes, but we rarely know which of the two mechanisms underlies the observed variance in body mass. We used phylogenetically informed comparisons of males and females of 19 Carabidae beetle species to compare body mass, resting metabolic rate, and cell size in the ommatidia and Malpighian tubules. We found that the larger species or larger sex (males or females, depending on the species) consistently possessed larger cells in the two tissues, indicating organism-wide coordination of cell size changes in different tissues and the contribution of these changes to the origin of evolutionary and sex differences in body mass. The species or sex with larger cells also exhibited lower mass-specific metabolic rates, and the interspecific mass scaling of metabolism was negatively allometric, indicating that large beetles with larger cells spent relatively less energy on maintenance than small beetles. These outcomes also support existing hypotheses about the fitness consequences of cell size changes, postulating that the low surface-to-volume ratio of large cells helps decrease the energetic demand of maintaining ionic gradients across cell membranes. Analyses with and without phylogenetic information yielded similar results, indicating that the observed patterns were not biased by shared ancestry. Overall, we suggest that natural selection does not operate on each trait independently and that the linkages between concerted cell size changes in different tissues, body mass and metabolic rate should thus be viewed as outcomes of correlational selection.