The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), is an obligately hematophagous insect with a broad host range including humans, bats, and chickens. There are significant interspecific and intraspecific differences in hematological parameters of these hosts, yet little is known about their effects on life history traits of bed bugs. In this study, we investigate the hematocrit, or red blood cell concentration, and its effects on bed bug fitness. We conducted dose-response experiments using human blood of different hematocrits, and assessed development time, feeding rate, adult body size, egg production, and egg hatch rate. Human blood with hematocrits ranging from 35% to 50% equally supported nymphal development. However, feeding bed bug nymphs a hematocrit of 60% resulted in high mortality (78%), low feeding rate, and none of the bed bug nymphs reached the adult stage. Additionally, bed bugs fed human blood with a 20% hematocrit emerged as significantly smaller adults. These results suggest a nutritional deficiency at low (∼20%) hematocrits and toxicity at high hematocrits (∼60%). In our assessment of fecundity, we observed maximal egg production at 35-50% hematocrit and deficiencies in egg production at low (20-30%) and high (60%) hematocrits. We conclude that bed bugs are well adapted to feed on a broad range of human blood hematocrits and hypothesize that this tolerance may allow them to thrive on alternative hosts. Considering the detrimental effects of very low and high hematocrits, studies that rely on laboratory rearing of hematophagous arthropods should consider hematological parameters during experimental design.

Species discovery within Odorrana has gradually increased over the years, establishing a remarkable diversity for the genus. During recent herpetological surveys, we collected specimens from Yingjiang County, Yunnan Province, China with additional samples from Thailand and Vietnam. Based on combined morphological and phylogenetic analyses, we describe a new species Odorrana sudianensis sp. nov. from Sudian Town, Yingjiang County, China and report new records of O. heatwolei for Thailand and Vietnam. Phylogenetic analyses, based on the 16S rRNA mitochondrial gene fragment, confirm the new species as a distinct evolutionary lineage with a genetic divergence ( p -distance) of 4.6% from its closest sister species O. dulongensis . Odorrana sudianensis sp. nov. is morphologically distinguishable from all its known congeners by having a robust medium adult body size, a head length longer than wide, a mottled grass-green dorsum with dark brown blotches on the posterior region, absence of dorsolateral folds and circum-marginal grooves for all finger discs expanded with lateroventral grooves. Additionally, the new species record sequences from Thailand and Vietnam nested within the O. heatwolei subclade with a low p -distance (0.0–0.5%) from topotypic sequences of O. heatwolei . Examined specimen shows morphological congruence with topotypic O. heatwolei in key diagnostic traits. Our new species and new species records increase the number of recognised species of Odorrana to 46 in China, seven in Thailand and 23 in Vietnam. We also address existing taxonomic disputes within Odorrana and provide comments and recommendations on the taxonomy of several species within the genus.

Under climate change, organisms with complex life cycles like insects are confronted with environmental cues that may interfere with their life cycle regulation, including diapause induction. Maladaptive responses to novel conditions may contribute to local or regional population declines and extinctions. In northwest Europe, the wall brown butterfly Lasiommata megera is a multivoltine species whose regional decline has been hypothesised to be related to recent warming in late summer and autumn increasing the probability of producing a late third generation instead of going into larval diapause to hibernate. To test this lost generation hypothesis, we exposed young larvae of different population origins to outdoor conditions and in situ warming (i.e. increased temperature at the level of the host plant by 0.5–3°C depending on the month). The warming treatment resulted in shorter larval developmental times and reduced adult body size. However, the population origin and the temperature treatment did not affect the probability to produce a third generation of adult butterflies at the end of summer. Yet, families showed substantial variation for the probability to induce a third generation. Overall, we observed reduced larval survival in the warming treatment. We discuss the implications of these results for the conservation of the wall brown in northwest Europe and, in a broader manner, for life cycle regulation in insects under rapid climate change.

Microbiome and physicochemical properties of breeding waters of Aedes albopictus mosquitoes in Sri Lanka.

Early Life Body Size Trajectory and the Risk of Primary Open-angle Glaucoma: A Retrospective Cohort Study.

Infancy is a critical period of rapid growth shaped by genetic, hormonal, and nutritional factors. Genetic influence on growth transitions from genetic variants associated with birth size to variants related to adult body size, however, the timing and developmental trajectory of these changes remain to be determined. To investigate how polygenic scores (PGS) for birth weight, adult BMI, height, and circulating levels of IGF-I relate to anthropometric measurements and IGF-I concentrations in healthy infants. Longitudinal cohort study: COPENHAGEN Minipuberty Study (2016-2018), with repeated anthropometric and hormonal assessments during the first year of life. Population-based. 210 healthy, term, singleton newborns (101 female). Age-specific standard deviation scores (SDS) for weight, length/height, and IGF-I serum levels; associations with PGSs and IGF-I levels across infancy. PGS for birth weight was associated with birth-weight SDS (P < 0.001) but not with weight SDS at ∼1 year (P = .07). In contrast, PGSs for adult BMI and adult height were associated with weight and height SDS at ∼1 year (P = .03 and P < .001, respectively). PGS for adult IGF-I was not associated with IGF-I SDS at 1 month but was significantly associated at 6 and 12 months (P < .001). Genetic influences on growth evolve during infancy. While the influence of genetic variants associated with birth size diminishes after birth, polygenic scores for adult traits and IGF-I regulation become increasingly relevant-already during early infancy-highlighting a dynamic transition in the genetic architecture underlying infant growth.

Body size variation in vertebrates is a complex polygenic trait, tightly correlated with numerous aspects of a species' biology, ecology, and physiology. Miniaturization, the extreme reduction of adult body size, is a common phenomenon across the Tree of Life, yet the mechanisms underlying this process are poorly understood. Here, we investigate the molecular basis of body size evolution in goby fishes, a clade encompassing some of the smallest vertebrates on Earth. We generate a genome-wide phylogeny for 162 Gobioidei species and perform comparative transcriptomics across three clades with repeated instances of miniaturization and large-bodied forms. We identified 54 differentially expressed one-to-one orthologs between miniature and large-bodied species. These genes reveal distinct functional profiles, suggesting that regulation of cell numbers is a key mechanism governing body size control. Miniature species consistently overexpress growth inhibitors like CDKN1B and ING2, associated with tighter cell cycle regulation and decreased proliferation rates, while large-bodied species upregulate growth-promoting genes such as TGFB3, linked to tissue development and growth signaling. These enriched functional pathways, conserved since the Eocene (50 Ma), suggest macroevolutionary convergence in size regulation over deep time. Our findings provide insights into how size determination is governed at a genetic level and highlights the importance of exploring these factors in nonmodel organisms to uncover the fundamental processes regulating vertebrate body size evolution.

Mitochondrial function relies on close coordination between the mitochondrial and nuclear genomes. Disruption to this coordination-via mitonuclear mismatch-can impair metabolic efficiency, particularly under energetically demanding conditions such as during development. The nutritional environment further modulates mitochondrial demands, suggesting that mitonuclear genotype and diet may interact to shape life-history traits and behaviour. Here, we investigate how early-life diet and mitonuclear genotype jointly influence development time, adult body size, and nutritional preference in Drosophila melanogaster. Using a full-factorial panel of putatively matched and mismatched combinations (cybrids) of mitonuclear genotype derived from natural Australian populations, we reared flies on diets varying in their ratio of macronutrients and assessed how this influenced larval development and subsequent adult diet preference. Developmental rate was significantly influenced by mitonuclear coevolution and diet, with cybrids showing delayed development under all conditions, with dietary extremes exacerbating this effect. Despite this, egg-to-adult viability remained unaffected. Adult nutritional behaviour exhibited clear genotype- and diet-dependent effects. Flies reared on high-protein diets increased carbohydrate intake as adults, while those reared on high-carbohydrate diets increased protein intake, suggesting compensatory feeding responses. Mitonuclear mismatch further modulated nutrient consumption, particularly in females, whose carbohydrate intake was influenced by intergenomic compatibility and early-life dietary conditions. Males' protein consumption was also impacted by mitonuclear coevolution across all developmental diets. Finally, body size was also shaped by interactions between mitonuclear genotype and diet. Together, our findings demonstrate that mitonuclear compatibility and the composition of the early nutritional environment interact to shape developmental and behavioural phenotypes. These results support a role for mitonuclear coadaptation in mediating metabolic plasticity, highlighting the evolutionary and physiological significance of genotype-specific mitonuclear coordination.

Evidence of declines in fish body size with warming in the absence of exploitation are lacking. During a period of regional climate warming (1986-2016), we examined trends in growth, size-structure, and age-structure of an unexploited population of Lake Trout (Salvelinus namaycush) from a small Canadian Shield Lake. These data were evaluated against long-term annual air and water temperature data, ice-cover data, and prey fish densities for the same period. Over time, the size of young immature Lake Trout did not change, while mature fish became smaller. The age-at-maturity of the population decreased by two years (from 6 to 4 years) and the body condition of immature and mature fish also declined. Though the adult Lake Trout population doubled over time (125 to 280 individuals), and the production (P), biomass (B), and biomass turnover (P/B) was constant, the population shifted to smaller, skinnier, younger individuals. By contrast, the relative abundance, biomass, and mean size of the prey fish community remained unchanged. Together this suggests that warming correlates with the contraction of the population’s life history.

With the intensification of agricultural practices, bee habitats are undergoing changes, impacting the nutritional quality of resources available to bee larvae and leading to variation in adult body sizes. Because larger bee species can forage at greater distances from their nests, we predicted that intraspecific body size would respond differently to agricultural land use gradient depending on bee size at the species level. Our study emphasizes the effect of a varying agricultural land use gradient on adult body sizes of bees. Our experiment took place in East Tennessee where we established twenty plots each containing 18 native plant species, at five sites of varying agricultural land-uses, ranging from 6-48% agriculture. During the summer, using an insect vacuum, we collected 11,183 insects representing 99 bee species interacting with these native plants. We then haphazardly selected adult bees from 13 species that were found at all sites to measure their body size via intertegular distance (ITD). We found that the intraspecific adult body size of larger bees, such as Bombus impatiens, increased along with agricultural land use in the surrounding landscape. The body size of small and medium sized bee species did not change along the agricultural land use gradient. This indicates that agricultural land use affects bee species differently. Larger bees are able to forage at greater distances from their nests and carry more provisions, which might make them more resilient to agricultural land use. Smaller bees may be less resilient because they cannot forage as far. This is critical to consider for future landscape management practices to best ensure the pollination of crops. KEYWORDS: Pollinator Health; Wild Bees; Agriculture; Conservation; Spatial Ecology; Social Bees; Intertegular Distance; Land Use Change

Performance and nutrient composition of black soldier fly larvae fed diets with various protein concentrations throughout the life cycle.

The mango stem borer Batocera rufomaculata is a large beetle (Cerambycidae) exhibiting a high intra-specific variation in adult body size because of differing environmental conditions during larval growth. Previous studies revealed that smaller individuals can fly longer distances than larger ones before reaching exhaustion, a surprising fact considering that the cost of transport is expected to increase with decreased body size. We tested the flight propensity and metabolic rhythms of these beetles as a function of sex and body size. The intrinsic flight-initiating behaviour and the daily fluctuations in metabolic rate (MR) were measured over 48 h in closed arenas and in metabolic chambers, respectively. Beetles displayed a strong circadian pattern of nocturnal activity in both locomotion and MR. Smaller conspecifics were significantly more active both metabolically and behaviourally than larger ones with sex having no effect on the size-related difference. The results suggest a stronger innate drive to disperse by flight in smaller conspecifics, providing a behavioural–physiological link between environmental conditions during the larval growth period and the dispersal potential of the adults.

Immune cells are increasingly recognized as nutrient sensors; however, their developmental role in regulating growth under homeostasis or dietary stress remains elusive. Here, we show that Drosophila larval macrophages, in response to excessive dietary sugar (HSD), reprogram their metabolic state by activating glycolysis, thereby enhancing TCA-cycle flux, and increasing lipogenesis-while concurrently maintaining a lipolytic state. Although this immune-metabolic configuration correlates with growth retardation under HSD, our genetic analyses reveal that enhanced lipogenesis supports growth, whereas glycolysis and lipolysis are growth-inhibitory. Notably, promoting immune-driven lipogenesis offsets early growth inhibition in imaginal discs caused by glycolytic and lipolytic immune-metabolic states. Our findings reveal a model of immune-metabolic imbalance, where growth-suppressive states (glycolysis, lipolysis) dominate over a growth-supportive lipogenic state, thereby impairing early organ size control and ultimately affecting adult size. Overall, this study provides important insights into dietary stress-induced immune-metabolic reprogramming and its link to organ size regulation and early developmental plasticity.

BackgroundThe relationships between body size changes and the risk of hypertension and metabolic dysfunction-associated steatotic liver disease (MASLD) are still unclear. This study examined the independent and combined influences of child and adult body size on the risk of adulthood hypertension and MASLD.MethodsWe included 226,420 participants from the UK Biobank who were free of hypertension and liver diseases. Child-to-adult body size categories were identified based on self-reported childhood body size and measured BMI in adulthood. Cox proportional hazard regression models were applied to assess the associations between body size categories and the incidence of hypertension and MASLD. Mediation analyses to address the effect of anthropometric measures and metabolic risk factors were also performed.ResultsAfter a median follow-up of approximately 13 years, 28,662 individuals had developed hypertension (N = 27,624) and/or MASLD (N = 1,692). Low body size in childhood increased the risk of adulthood hypertension and MASLD, regardless of adult body size. Individuals with low child body size and high adult body size exhibited the highest risk for both hypertension (HR 2.01, P < 0.001) and MASLD (HR 3.28, P < 0.001). Individuals who had high child body size but average body size in adulthood had risks of the two diseases that were similar to those of persons who had an average body size consistently (all P > 0.05). Body size changes influenced hypertension through significant natural direct effects and indirect effects via anthropometric and metabolic factors, while their impact on MASLD was primarily mediated by these factors without significant direct effects.ConclusionsChildhood leanness exacerbates the risk of hypertension and MASLD in adulthood. Within the follow-up period, normal adult body size would mitigate the detrimental effects of childhood obesity. Thus, attention should be given to reinforcing weight management in children by implementing evidence-based strategies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-025-24317-4.

Broad bean is one of the most important leguminous crops worldwide. However, its productivity is greatly affected by the infestation of Aphis fabae and Aphis craccivora (Hemiptera: Aphididae). The main objective of the current study was to identify the most susceptible phenological stages of the broad bean variety (Histal) against black aphids' herbivory. This had been achieved through an evaluation of plant resistance mechanisms such as antixenosis and antibiosis. The results regarding an antixenosis test revealed that the four tested phenological stages of V. faba did not have a significant effect on the preference of A. craccivora and A. fabae towards the crop plant. Overall, a slightly higher number of adults settled on the three and four unfolded leaves' stage of the crop plant. Similarly, the highest number of developed embryos were found in the four leaves' stage of the crop, and the lowest in the second leaf stage. The adult body size of A. craccivora was slightly larger in the case of the three unfolded leaves. Furthermore, the maximum body size of A. fabae adults was recorded in the case of the first unfolded leaf stage crop. Linear correlations between the biological parameters for both species revealed only one significant relationship between developed and total embryos for A. craccivora. The results of the current study highlight the need to protect broad bean crops against infestations of black aphids, i.e., A. craccivora and A. fabae. This is essential for reducing direct damage and preventing the transmission of phytoviruses. However, future studies should aim to evaluate the susceptibility of all developmental phenological stages of the crop against black aphids to mitigate potential crop losses.

Abstract Geographic size variation in ectotherms often reflects complex interactions between environmental and evolutionary factors, which can differ among taxa. In this study, we investigated body size patterns in two sister subspecies of spur‐thighed tortoises, Testudo graeca whitei and T. g. marokkensis, across their natural ranges in North Africa. These subspecies show distinct climatic niches, and we hypothesized that their morphology would differ in response to environmental variables, such as climate, Normalized Difference Vegetation Index (NDVI, a measure of vegetation cover), latitude, and elevation. We measured tortoises across Morocco and Algeria to explore growth patterns and adult body size in response to these environmental factors. Growth models revealed significant sexual size dimorphism in both subspecies. The humid subspecies T. g. marokkensis exhibited a slower growth rate but reached a larger asymptotic size compared with the semiarid T. g. whitei. When evaluating the relationship between body size and environmental factors, we found that T. g. whitei exhibited a negative correlation between body size and latitude, which contrasts with Bergmann's rule. By contrast, T. g. marokkensis followed the rule, with body size positively correlated with both latitude and elevation. Our findings suggest that latitude and elevation are encompassing critical factors influencing body size, reflecting the impact of climatic factors like aridity on tortoise morphology. We also found that body size patterns aligned with niche divergence, with larger individuals of both sexes occurring in regions with more favorable climatic conditions. Indirectly, these results suggest that larger body size in T. graeca may be associated with higher fitness in both males and females.

Abstract One potential predictor of adult reproductive success is physical condition, which can be influenced by earlier developmental stages, such as nutritional limitations during juvenile growth. Sodium is a vital element for animals, essential for physiological function and individual‐level development and behaviour. When animals are sodium‐limited, they at times engage in behaviours such as cannibalism or geophagy to obtain sodium. At high levels, sodium may be toxic and result in adverse physiological effects. How dietary variation in sodium availability during larval stages influences adult mating behaviour and reproductive output has received relatively little attention. Previous studies within Lepidoptera have reported varied results. We used the bordered patch butterfly, Chlosyne lacinia (Geyer, 1837; Nymphalidae), to investigate the role of larval dietary sodium uptake on adult body size, lifespan, mating behaviour and reproductive success. Body size did not differ between treatments. Individuals raised on host plants with high‐sodium concentrations had shorter lifespans than those reared on low‐sodium host plants, indicating that sodium in high concentrations in larval diets can be harmful. Females raised on lower sodium diets took longer to start mating regardless of males' larval access to sodium, but copulation durations did not differ. Males and females raised on host plants with higher sodium concentrations mostly did not pair differently than individuals raised on host plants with lower sodium concentrations and did not differ in their immediate reproductive success. Females raised on high‐sodium host plants avoided mating with males raised on high‐sodium host treatments, suggesting that larval sodium acquisition could influence reproductive decisions made by adults. Reproductive success in insects is shaped by both intrinsic behavioural strategies and extrinsic environmental factors. During mating, individuals make complex choices to maximise fitness, and environmental conditions experienced during juvenile stages—such as dietary sodium exposure—can influence reproductive decisions in adulthood. Understanding the role of sodium in these life‐history traits is increasingly important in light of global ecological change: drought‐driven reliance on saline irrigation is accelerating soil salinisation worldwide, which may in turn disrupt insect–plant interactions and destabilise multi‐trophic dynamics. Collectively, these findings underscore how adaptive behaviours and environmental stressors interact to shape insect populations in a rapidly changing world.

The life histories of Palaeocene mammals are poorly known, but may have been central to their success in diversifying across terrestrial ecosystems after the end‐Cretaceous extinction. Among these mammalian groups, the eutherian Taeniodonta are particularly enigmatic, with few modern analogues and no living descendants, despite being one of the only lineages to apparently traverse the Cretaceous‐Palaeogene (K‐Pg) boundary. Here, we investigate the life history of an early Palaeocene taeniodont, Conoryctes comma, based on a multi‐individual, multi‐element sample. Nearly all elements sampled exhibit similar osteohistological architecture, with a small internal zone of compacted coarse cancellous bone surrounded by an internal cortex of periosteally derived fibrolamellar bone of variable thickness, and an outer cortex of lamellar bone. The well‐vascularized fibrolamellar complex in the limb bones, lacking cyclical growth marks, is indicative of overall rapid growth to near adult body size. Cyclical growth marks are present in the outer cortex after the transition to slow‐growing lamellar bone, but not in the inner cortex, suggesting sexual maturity was reached in 1 year. In some elements, an internal non‐cyclical growth mark shares histological similarities with weaning marks in living mammals and other contemporary Palaeocene mammals, and occurred at the body size predicted for this transition in therian mammals. The unusual presence of compacted coarse cancellous bone near the midshafts of multiple limb bones may be related to cortical thickening, and is similar to the arrangement described in some fossorial mammals, supporting previous assertions of this lifestyle in Conoryctes. Altogether, these palaeohistological signals suggest a life history in C. comma similar to living eutherians, despite uncertainty about whether it is within crown Placentalia or a close outgroup. Thus, our data are consistent with an early origin of placental‐like reproductive strategies in their eutherian ancestors, although this attribute was likely shared more broadly among Mesozoic mammal lineages prior to the end‐Cretaceous extinction.

Larviciding is an important part of effective integrated mosquito management. However, growing resistance to chemical- and bacterial-based insecticides requires biocontrol agents with novel modes of action. Entomopathogenic fungi are good candidates for larval control due to their capability to infect mosquito larvae and their production of larvicidal compounds. In this study, we isolated a strain of Trichoderma atroviride from Aedes albopictus larvae collected in Manhattan, KS, USA. We used a laboratory-based microcosm assay to expose L3 Ae. albopictus larvae to T. atroviride conidia and culture supernatant treatments. Larvae were monitored daily for survival and development to pupae and adults. In addition, adult survival was monitored for 10 d postpupation, and wing lengths were measured to assess mosquito size. Our results revealed that T. atroviride culture supernatant was a potent larvicide toward Ae. albopictus. However, conidia by themselves were not larvicidal, indicating the major mode of killing was through toxicity exerted by the culture supernatant. We further show that larval exposure to T. atroviride supernatant delayed larval development to pupae. Sex-specific adult survival was not affected by larval exposure to T. atroviride. However, wing length of male and female mosquitoes were reduced, indicating a reduction in adult mosquito body size as compared to the control. Taken together, this study identifies the culture supernatant from a novel strain of T. atroviride as a potent larvicide of Ae. albopictus, potentially expanding the toolbox for biological control of mosquitoes.

ABSTRACTModels of herbivorous insect phenology can be used to make agriculture more sustainable and to better manage the effects of climate change on natural communities. The phenology of herbivorous insects depends on heat time, but exactly how it varies across populations and the causes of this variation are unclear. Here, with multilevel Bayesian models, we performed a comparative analysis of 601 published herbivorous insect phenology models. We found that variation in herbivorous insect phenology can be explained by variation in phylogenetic relatedness, adult body size, feeding site, host plant taxonomy, geographic location, and the approaches that researchers used for model parameterization. Contrary to previous analysis, we also found that the minimum temperature required for development varies across life stages in a way that could be adaptive. Our analysis demonstrates that by accounting for more information on the variation across insect populations and their environments, we can make better and more generalizable predictions of herbivorous insect phenology.