Impacts of climate warming on terrestrial ectotherms across latitude

Contrasting effects of climate and anthropogenic change on future invasion risk of a solitary bee Amegilla pulchra

Amegilla pulchra is a solitary bee from Australia that has recently been spread throughout many islands of the Pacific. The non-regulated human-driven spread of the species may affect the local pollinator communities and their interactions with host plants. We used an ecological niche modelling approach, accounting for non-equilibrium and anthropogenic spread with the most recently recommended methods, and predicted the potential spread of the species under current and future conditions. We expected climate change and increase in human density to offer new suitable environments for the spread of the species. Invasion risks will increase in the future overall, but more in the non-native regions compared to the native region. In the native region, the projected effect of future environmental change was highly contrasted, we projected invasion risk to increase in human-dense areas but decrease elsewhere. We identified high risks of invasion in eastern Asia and in the Caribbean region and provide a world ranking for surveillance priority which accounts for maritime traffic. This study highlights potential contrasted effects between climate and anthropogenic change, with differing projections between the native and the non-native regions. Public awareness and prevention will be key to prevent further spread and mitigate potential adverse effects of the species on island systems. In regions that are already invaded, we propose that habitat restoration is a promising strategy for both the mitigation of the spread and the conservation of local communities.

Above-ground xylem genes and below-ground soil carbon genes analyses provide molecular insights into experimental warming in Phoebe chekiangensis

Phoebe chekiangensis C. B. Shang is an endemic and endangered species in China, and it is widely used for furniture, building materials and artwork due to its high-quality wood properties and high economic value. However, the impact of spring warming on P. chekiangensis growth molecular dynamics are poorly understood. In this study, we used a year-long warming control experiment (CK, +2 °C, +4 °C) to explore the molecular dynamics of aboveground xylem genes and belowground soil carbon genes. Transcriptome results indicated that spring warming primarily affects genes and pathways related to cell growth, lignin, photosynthesis, and cell wall macromolecules. Carbon fixation genes abundance increased significantly over time in the CK and + 2 °C groups, but no significant increase was observed in the +4 °C group. In addition, spring warming reduced the diversity of microbial communities which may be one of the reasons for reduced tree growth. These findings revealed the mechanisms underlying xylem and carbon cycling genes responses to varying temperature increases in P. chekiangensis. Our results provided valuable insights for future research on wood-related molecular mechanisms and offer a foundational basis for uniting aboveground xylem growth and belowground carbon genes to together influence seasonal development of wood.

Assessing the combined effects of elevated temperature and chlorpyrifos on meiobenthic community structure in intertidal and mangrove estuarine ecosystems

In the age of anthropocene, elevated temperatures and pesticide pollution represent critical environmental challenges with profound ecological implications. As crucial bio-indicator, meiobenthic organisms play a pivotal role to assess the impacts of these disturbances on ecosystem health. Despite their ecological significance, the combined impacts of these stressors on meiobenthic community structures remain unexplored. This study investigates the acute exposure of elevated temperature (34 °C) and chlorpyrifos contamination (at 3 μg L-1 and 4.5 μg L-1) on meiobenthic community structure from mangrove mudflat and intertidal sandflat. A 10-days acute benthocosm experiment unveiled significant declines in total meiobenthic abundance under high-stress conditions; 75 % and 73 % in mangrove mudflat and intertidal sandflat respectively. A 4-factor PERMANOVA revealed significant effects of temperature, pesticide, and exposure duration on meiobenthic abundance (p < 0.05). Sensitive taxa such as kinorhyncha, bivalvia, and ostracoda were eliminated from treated benthocosms. Nematode species composition also affected and shifted under stress, with opportunistic and stress tolerant species became dominant. Nematode abundance decreased by up to 65 % and 63 % in the mangrove mudflat and intertidal sandflat, correspondingly. Species diversity, richness, and Shannon-Wiener index (H') significantly declined, with changes in the Maturity Index (MI) and Index of Trophic Diversity (ITD). The effects of combined stressors were more pronounced than individual stressors and mangrove mudflat displayed slightly higher susceptibility than intertidal sandflat. According to Hierarchical Modelling of Species Communities (HMSC) a noticeable influence of habitat type, stressors levels and exposure duration on the sensitivity of nematode species has been observed.

Effects of Climate Warming on Overwintering of Qinghai Toad-Headed Lizards at Two Contrasting Elevations

Increases in temperature associated with global warming have significant implications for organismal fitness. Thermal condition changes of inactive or dormant periods (such as winters) also have important effects on animals, particularly for ectotherms. Neglecting the potential consequences of winter warming can lead to biases in assessing the effect of climate change. The impacts of winter warming on ectotherms may be complex and multifaceted, possibly varying with geographic location including thermal ecological niche, altitude, and latitude. Therefore, we conducted field warming experiments (warmer climate vs. present climate) to investigate the effects of winter warming on the mass loss, body condition, physiological process, and survival capacity of Qinghai toad-headed lizards (Phrynocephalus vlangalii) at two contrasting altitudes (2600 vs. 3600 m) of the northern Qinghai-Xizang Plateau, China. The warming treatment reduced mass loss of the 2600-m-altitude lizard population, enhanced body condition, and increased overwintering survival rate after hibernation, while there was no significant effect on these indicators for the 3600-m-altitude lizard population with warming treatment. The two altitudinal populations showed different regulatory patterns of metabolic pathways in response to warming winters. Under simulated warming, the 2600-m-altitude lizard population mostly downregulated energy metabolism-related pathways (e.g., glycolysis, pyruvate metabolism, fatty acid degradation, TCA cycle, and oxidative phosphorylation) during hibernation. In contrast, under winter warming, the 3600-m-altitude lizard population primarily upregulated amino acid metabolism pathways (including serine and threonine metabolism; alanine, aspartate, and glutamate metabolism; cysteine and methionine metabolism; as well as histidine metabolism), which may be associated with cold stress adaptation. These findings contribute to our understanding of the adaptive effects of winter warming on reptiles and their physiological mechanisms, facilitating a better assessment of vulnerability to climate change.

High altitude favours long-chained cuticular hydrocarbons in Drosophila

Cuticular hydrocarbons (CHCs) are key components of the insect cuticle and contribute to the wide geographical distribution of this taxon. Many studies have investigated sex and population differences in CHC profiles, with these investigations mostly focusing on latitudinal CHC variation, whereas CHC variation across altitudinal transects is less well-studied. Here, we tested whether CHC profiles vary along an altitudinal gradient in the cosmopolitan vinegar fly Drosophila melanogaster. We collected from three populations of D. melanogaster in the Western Himalayas at altitudes ranging from 760 to 2,592 m above sea level and tested their CHC profiles for standing and plastic variation. We found quantitative differences in 25 CHCs across populations, and at higher elevations, males and females expressed higher amounts of particular long-chained hydrocarbons. We also found plastic shifts in CHC profiles in all three populations when flies were exposed to desiccating conditions. Overall, our findings suggest that there is an altitudinal cline in CHCs. However, this does not mirror the well-established latitudinal clines in fly hydrocarbons.

Experimental evolution reveals trade-offs between sexual selection and heat tolerance in Drosophila prolongata

Sexual selection promotes traits that enhance mating or fertilization success, but these traits can be very costly under harsh environmental conditions. The extent to which differential investment in costly traits under varying intensities of sexual selection is related to their susceptibility to environmental stress remains unclear. This study explored how experimental evolution under different operational sex ratios (OSRs) shapes traits and reproductive success of male Drosophila prolongata, and how developmental and/or adult heat stress affect the expression of these traits. We found males from even and slightly male-biased OSRs to be larger and display greater reduction in body size under developmental heat stress, suggesting pre-mating sexual selection on body size and condition-dependent thermal sensitivity. These populations also exhibited consistently high mating and fertilization success across temperatures, potentially indicating selection for robust phenotypes with "good genes" that perform well regardless of temperature. Conversely, males from strongly male-biased OSR populations experienced more pronounced decline in sperm competitiveness following exposure to developmental or adult heat stress. These results highlight how environmental stressors differentially impact populations, shaped by varying strengths of pre- and post-mating sexual selection. These observed patterns suggest potential interactions between past selection and the ability to adapt to changing environments.

The gut-liver axis plays a limited role in mediating the liver's heat susceptibility of Chinese giant salamander

The Chinese giant salamander (CGS, Andrias davidianus), a flagship amphibian species, is highly vulnerable to high temperatures, posing a significant threat under future climate change. Previous research linked this susceptibility to liver energy deficiency, accompanied by shifts in gut microbiota and reduced food conversion rates, raising questions about the role of the gut-liver axis in mediating heat sensitivity. This study investigated the responses of Chinese giant salamander larvae to a temperature gradient (10-30 °C), assessing physiological changes alongside histological, gut metagenomic, and tissue transcriptomic analyses. Temperatures above 20 °C led to mortality, which resulted in delayed growth. Histological and transcriptomic data revealed metabolic exhaustion and liver fibrosis in heat-stressed salamanders, underscoring the liver's critical role in heat sensitivity. While heat stress altered the gut microbiota's community structure, their functional profiles, especially in nutrient absorption and transformation, remained stable. Both gut and liver showed temperature-dependent transcriptional changes, sharing some common variations in actins, heat shock proteins, and genes related to transcription and translation. However, their energy metabolism exhibited opposite trends: it was downregulated in the liver but upregulated in the gut, with the gut showing increased activity in the pentose phosphate pathway and oxidative phosphorylation, potentially countering metabolic exhaustion. Our findings reveal that the liver of the larvae exhibits greater thermal sensitivity than the gut, and the gut-liver axis plays a limited role in mediating thermal intolerance. This study enhances mechanistic understanding of CGS heat susceptibility, providing a foundation for targeted conservation strategies in the face of climate change.

Incorporating adult age into mosquito population models: Implications for predicting abundances in changing climates

Mosquito-borne diseases (MBDs) pose increasing threats under future climate change scenarios and an understanding of mosquito population dynamics is pivotal to predicting future risk of MBDs. Most models that describe mosquito population dynamics often assume that adult life-history is independent of adult age and yet mosquito senescence is known to affect mosquito mortality, fecundity and other key biological traits. Despite this, little is known about the effects of adult age at the level of the mosquito population, especially under varying temperature scenarios. We develop a stage-structured delayed differential equations (DDEs) model incorporating the effects of the abiotic environment and adult age to shed light on the complex interactions between age, temperature, and mosquito population dynamics. Taking Culex pipiens, a major vector of West Nile Virus, as our study species our results show that failing to consider mosquito senescence can lead to underestimates of future mosquito abundances predicted under climate change scenarios. We also find that the age-dependent mechanisms combined with the effects of density-dependent mortality on the immature stages can result in mosquito abundances decreasing at extreme temperatures. With our work, we underscore the need for more studies to consider the effects of mosquito age. Not accounting for senescence can compromise the accuracy of abundance estimates and has implications for predicting the risk of future MBD outbreaks.

Polar ectotherms more vulnerable to warming than expected

Polar regions are heavily impacted by climate change. Yet, vulnerability assessments suggest little concern about heat-related challenges for polar terrestrial ectotherms. These conclusions are based, however, on assumptions and extrapolation from temperate regions; the limited data available suggest that polar ectotherms are more sensitive to warming than previously recognized.

Local adaptation has a role in reducing vulnerability to climate change in a widespread Amazonian forest lizard

The extant genetic variation within and among taxa reflects a long history of diversification and adaptive mechanisms in response to climate change and landscape alterations. However, the velocity of current anthropogenic changes poses an imminent threat to global biodiversity. Understanding how species and populations might respond to global climate change provides valuable information for conservation in the face of these impacts. Here, we use genomic data to observe candidate loci under climate selection and test for genetic vulnerability to climate change in a widespread Amazonian ombrophilous lizard population. We found nine populations across Amazonia with a considerable amount of admixture among them. Distinct approaches of genome-environment association analyses revealed 56 candidate single-nucleotide polymorphisms (SNPs) under climatic selection, showing an east-west gradient in the adaptive landscape and a signal of local climate adaptation across the species range. According to our results, signals of local adaptation indicate that the species may not respond equally throughout its range, with some populations facing higher extinction risks. Genomic offset analysis predicts the southern and central portions of Amazonia to have a higher vulnerability to future climate change. Our findings highlight the importance of considering spatially explicit contexts with a large sampling coverage to evaluate how local adaptation and climatic vulnerability affect Amazonian forest ectothermic fauna.

The Semi-Natural Climate Chambers across Latitudes: A Broadly Applicable Husbandry and Experimental System for Terrestrial Ectotherms under Climate Change

With limited resources and efforts, assessing species' vulnerabilities across various geographic regions before the conservation practice is essential for biodiversity conservation in the context of climate change. One pressing challenge has been establishing natural temperature-manipulated research systems across latitudes. To address this challenge, an innovative infrastructure is developed named the semi-natural climate chambers across latitudes (SCCAL), consisting of semi-natural climate chambers at three latitudes, spanning 27° and 3393 km from tropical to temperate regions. Each latitude features eight medium-sized patches for temperature manipulation, organisms rearing, and ecological experiments. Independent of external water and electricity supplies, the SCCAL allows to simulate thermal environments under different climate change scenarios with natural soil moisture. Ecological experiments with Grass lizards successfully are conducted, demonstrating that the SCCAL effectively supports species rearing, responses determining, and the vulnerability assessing. The widespread adoption or development of similar infrastructures is encouraged, which can facilitate the assessment of latitudinal animal vulnerabilities under climate change.

Two Hypotheses About Climate Change and Species Distributions

Species' distributions are changing around the planet as a result of global climate change. Most research has focused on shifts in mean climate conditions, leaving the effects of increased environmental variability comparatively underexplored. This paper proposes two new macroecological hypotheses-the variability damping hypothesis and the variability adaptation hypothesis-to understand how ecological dynamics and evolutionary history could influence biogeographic patterns being forced by contemporary large-scale climate change across all major ecosystems. The variability damping hypothesis predicts that distributions of species living in deep water environments will be least affected by increasing climate-driven temperature variability compared with species in nearshore, intertidal and terrestrial environments. The variability adaptation hypothesis predicts the opposite. Where available, we discuss how the existing evidence aligns with these hypotheses and propose ways in which they may be empirically tested.

Sex-specific variation in thermal sensitivity has multiple negative effects on reproductive trait performance

Understanding how increasing temperatures influence ectotherm population growth rate is necessary for predicting population persistence. Population growth rate depends on the thermal performance of multiple life-history traits that have different thermal sensitivities. Reproductive traits are considered more thermally sensitive than other life-history traits, such as survival and development rate. Moreover, the thermal sensitivity of reproductive traits can be sex-specific, which may differentially affect population growth. However, research concurrently assessing the sex-specific influence of heat stress on multiple reproductive traits is limited. We investigated the effect of heat stress on pupal survival and reproductive traits in both sexes to determine sex-specific thermal sensitivity and reproductive performance. Individuals of the butterfly Pieris napi were reared at either 22°C or 29°C throughout the larval and pupal stages. The latter temperature reflects the fastest development rate in this population, influencing generation time, a common population growth rate metric. We recorded pupal survival and adult body weight in both sexes. After eclosion, males and females from both treatments were allowed to interact, and mating success, copulation duration, egg production, fertility and male sterility recovery were measured. A subset of mated females was dissected to assess the number and length of fertilising eupyrene and non-fertilising apyrene sperm transferred by males of each treatment. While elevated temperatures reduced pupal survival and resulted in smaller body weights in both sexes, more substantial sex-specific effects on reproductive traits were observed. Mating success was reduced in heat-stressed females but not in males. In contrast, egg production and fertility were unaffected by heat stress in females, while heat-stressed males, despite having longer copulation durations, exhibited near-complete sterility. Male heat-induced sterility was mediated by a disruption to both eupyrene and apyrene sperm production or transfer. Male remating did not recover fertility, suggesting continued negative effects on sperm production. Our results highlight how increasing temperatures affect reproduction, illustrating that temperatures generating optimal performance for non-reproductive traits, like development rate, can negatively and differentially impact sex-specific reproductive fitness. These negative reproductive consequences may impact population persistence, highlighting the necessity to incorporate these findings into future advanced models predicting species' responses to climate warming.

The ultimate challenge to climate change: Endurance of a thermophilic reptile to the harsh temperatures on an extremely hot island

Herbivorous ectotherms are especially vulnerable to climate change and those inhabiting hot environments may already live near their maximum physiological limits. Insular species are particularly susceptible to changing thermal conditions because they cannot relocate. This proves a very poor prognostic for the survival of herbivorous reptiles living on islands. The piebald chuckwalla, Sauromalus varius, is a large iguana endemic to San Esteban Island, located in the Gulf of California, encompassed by the Sonoran Desert, one of the hottest areas on earth. We investigated the thermal ecology of this iguana during the hottest month of the year coinciding with the fruiting of its most important food source, the giant cardon. We measured field body temperature (Tbfield), voluntary maximum body temperature, the onset of thermal stress responses, and critical maximum temperature, and compared these with the thermal landscape. We found that Tbfield was 37.2±1.3°C (average±SD) and iguanas sought shade at a body temperature of 39.2±1.4°C. Iguanas started panting at 42.4±2.0°C, a cooling strategy at the expense of precious body water, and often defecated, at 43.2±1.9°C, with concomitant loss of water. We determined that these iguanas can maintain activity at body temperatures of 47.2±2.2°C, however they use various mechanical and behavioral mechanism to avoid these extremes. On the island, ground temperatures reached up to 62.4°C. Shade of plants can provide thermal shelter during part of the day. However, even in some caves temperatures could reach 41.5°C and under rocks 48.0°C, which is higher than these animals voluntarily tolerate. Our results indicated that although these chuckwallas can support high temperatures, their strategy incurs substantial water loss, a resource only available for the iguana through cacti consumption. Environmental temperature that increases with climate change will likely lead to an ever-increasing use of shelters, perhaps even resulting in complete inactivity during the cacti fruiting period.

Climate change is projected to shrink phylogenetic endemism of Neotropical frogs

Climate change is widely recognized as one of the main threats to biodiversity1 and predicting its consequences is critical to conservation efforts. A wide range of studies have evaluated the effects of future climate using taxon-based metrics3,4, but few studies to date have applied a phylogenetic approach to forecast these impacts. Here, we show that future climate change is expected to significantly modify not only species richness, but also phylogenetic diversity and phylogenetic endemism of Neotropical frogs. Our results show that by 2050, the ranges of 42.20% (n = 213) of species are projected to shrink and the range of 1.71% of species (n = 9) are projected to disappear. Furthermore, we find that areas of high SR and PD are not always congruent with areas of high PE. Our study highlights the projected impacts of climate change on Neotropical frog diversity and identifies target areas for conservation efforts that consider not just species numbers, but also distinct evolutionary histories.

Experimental short-term heatwaves negatively impact body weight gain and survival during larval development in Bombus terrestris L. (Hymenoptera: Apidae)

Climate change-induced heatwaves threaten global biodiversity, including crucial pollinators like bumblebees. In particular, the increasing frequency, duration and intensity of heatwaves is alarming. Despite these projections, little is known about the effects of short-term heatwaves on insect larval development. Hence, we investigated the impact of simulated heatwaves on the development of 4th instar larvae (L4) of Bombus terrestris L. (Hymenoptera: Apidae) using an in vitro rearing method. Individual larvae were incubated at 37°C and 38°C for a period of 4 days, with a constant rearing temperature of 34°C as the control. We examined body weight gain, developmental duration, survival to adult stage, and adult body size (i.e. dry mass, intertegular distance, and head width). A simulated heatwave of 37°C did not significantly affect larval development, but 38°C impaired larval body mass gain. While developmental duration and adult body size were unaffected, an acute heat stress of 38°C during the L4 stage reduced the probability of pupae reaching adulthood. These findings highlight the potential for heatwaves to negatively affect bee populations by impairing larval growth and reducing survival to the adult stage, which may have severe implications for colony fitness.

Mean daily temperatures predict the thermal limits of malaria transmission better than hourly rate summation

Temperature shapes the geographic distribution, seasonality, and magnitude of mosquito-borne disease outbreaks. Models predicting transmission often use mosquito and pathogen thermal responses measured at constant temperatures. However, mosquitoes live in fluctuating temperatures. Rate summation--non-linear averaging of trait values measured at constant temperatures-is commonly used to infer performance in fluctuating environments, but its accuracy is rarely validated. We measured three traits that impact transmission-bite rate, survival, fecundity-in a malaria mosquito (Anopheles stephensi) across three diurnal temperature ranges (0, 9, and 12 °C). We compared transmission thermal suitability models with temperature-trait relationships observed under constant temperatures, fluctuating temperatures, and those predicted by rate summation. We mapped results across An. stephenesi's native Asian and invasive African ranges. We found: 1) daily temperature fluctuation trait values substantially differ from both constant temperature experiments and rate summation; 2) rate summation partially captured decreases in performance near thermal optima, yet incorrectly predicted increases near thermal limits; and 3) while thermal suitability across constant temperatures did not perfectly capture fluctuating environments, it was better than rate summation for estimating and mapping thermal limits. Our study provides insight into methods for predicting mosquito-borne disease risk and emphasizes the need to improve understanding of organismal performance under fluctuating conditions.

Thermal effects on metabolic rate in diapausing Pieris rapae butterflies

As ectotherms, many insects spend the winter months in a state of suspended animation (i.e., diapause), lowering their metabolic rates to subsist on a limited store of energy reserves. The ability to lower metabolic rate during diapause relies, in part, on cold winter temperatures to intrinsically lower metabolic rate. Winter warming associated with global climate change may pose a challenge to diapausing insects by intrinsically increasing metabolic rate, potentially leading to the exhaustion of energetic reserves. We used stop-flow respirometry to measure oxygen consumption in response to temperatures representative of both acute and chronic winter warming scenarios in diapausing Pieris rapae pupae. Metabolic rate increased with increasing temperature in diapausing pupae, but metabolic rate depended on both pupal age and warming severity, with older pupae having lower metabolic rates overall. Despite the increases in metabolic rate, pupae recovered metabolic rate within 24-hours after short-term acute-warming exposure. In contrast, chronic exposure to warming over weeks and months led to significant decreases in metabolic rate later in diapause, as well as reductions in pupal mass. These results demonstrate that while respiration was thermally responsive, warming did not lead to sustained increases in metabolic rate. Instead, diapausing P. rapae appear to acclimate to higher temperature by lowering their metabolic rates in response to months of chronic warming. Overall, these patterns suggest that this species could be resilient to winter warming, at least in the context of energetics. However, the precise mechanisms underlying these responses remain to be characterized. Thus, future research-e.g., on the genetic underpinnings of energetics in the context of warming-could further elucidate the relative vulnerability of diapausing insects to future winter warming.

Genetic Architecture of the Thermal Tolerance Landscape in Drosophila melanogaster

Increased environmental temperatures associated with global warming strongly impact natural populations of ectothermic species. Therefore, it is crucial to understand the genetic basis and evolutionary potential of heat tolerance. However, heat tolerance and its genetic components depend on the methodology, making it difficult to predict the adaptive responses to global warming. Here, we measured the knockdown time for 100 lines from the Drosophila Genetic Reference Panel (DGRP) at four different static temperatures, and we estimated their thermal-death-time (TDT) curves, which incorporate the magnitude and the time of exposure to thermal stress, to determine the genetic basis of the thermal tolerance landscape. Through quantitative genetic analyses, the knockdown time showed a significant heritability at different temperatures and that its genetic correlations decreased as temperatures differences increased. Significant genotype-by-sex and genotype-by-environment interactions were noted for heat tolerance. We also discovered genetic variability for the two parameters of TDT: CTmax and thermal sensitivity. Taking advantage of the DGRP, we performed a GWAS and identified multiple variants associated with the TDT parameters, which mapped to genes related to signalling and developmental functions. We performed functional validations for some candidate genes using RNAi, which revealed that genes such as mam, KNCQ, or robo3 affect the knockdown time at a specific temperature but are not associated with the TDT parameters. In conlusion, the thermal tolerance landscape display genetic variation and plastic responses, which may facilitate the adaptation of Drosophila populations to a changing world.

Novel Regimes of Extreme Climatic Events Trigger Negative Population Rates in a Common Insect

The IPCC predicts that events at the extreme tail of the probability distribution will increase at a higher rate relative to less severe but still abnormal events. Such outlier events are of particular concern due to nonlinear physiological and demographic responses to climatic exposure, meaning that these events are expected to have disproportionate impacts on populations over the next decades (so called low-likelihood, high-impact events -LLHI). Because such events are historically rare, forecasting how biodiversity will respond requires mechanistic models that integrate the fundamental processes driving biological responses to our changing climate. Here we built a matrix population model (MPM) from long-term monitored populations of an insect model species in a Mediterranean area. The model simultaneously integrates the effects of extreme microclimatic heat exposure and drought-induced host-plant scarcity on early life stages, a key methodological step forward because these understudied life stages are usually very susceptible to climatic events. This model for the first time allowed us to forecast the demographic impacts that LLHI events will have on a well-known insect considering their whole life cycle. We found that juveniles were the life stage with the largest relative contribution to population dynamics. In line with field observations, simulated population rates in current climatic regimes were importantly determined by drought impacts, producing a regional mosaic of non-declining and declining populations. The simulations also indicated that in future, climate scenarios not meeting the Paris Agreement, LLHI heat extremes triggered regionally widespread and severe declines in this currently abundant species. Our results suggest that LLHI events could thus emerge as a critical new -but overlooked- driver of the declines in insect populations, risking the crucial ecosystem functions they perform. We suggest that process-based and whole-cycle modelling approaches are a fundamental tool with which to understand the true impacts of climate change.

Hydrothermal physiology and vulnerability to climatic change: insight from European vipers

Clarifying physiological adaptations is crucial to understand species distribution and predict vulnerability to changing climatic conditions. Considering energy and water constraints jointly is necessary because these facets are intertwined in ectotherms. The genus Vipera is a diversified group of Palearctic snakes with parapatric distributions and contrasted climatic affinities. These species are active thermoregulators relying on basking to maintain their body temperature. While some species such as V. berus and V. seoanei are adapted to cold and wet environments, other species have intermediate (temperate-oceanic) affinities (V. aspis), and some such as V. latastei and V. ammodytes inhabit warm and semi-arid climates. We studied physiological traits related to energy and water balance in these five species to better understand species' vulnerability to climate change. First, using open-flow respirometry we quantified standard metabolic rate (SMR) and evaporative water loss (TEWL) at three temperatures (15 °C, 25 °C and 33 °C). Cold- and wet-adapted species exhibited higher metabolic rates and evaporative water loss, reflecting adaptations to colder, wetter environments, while warm- and dry-adapted species showed lower rates. Second, we used these data to investigate their physiological responses to extreme climatic events (ECE). Simulated responses to summer heat spells revealed a major increase in energy expenditure and water loss rates across species. However, the effect was more prominent in cold- and wet-adapted species. This study underscores the physiological constraints that cold and wet-adapted species face during extreme climate events, providing insights into the vulnerabilities of ectotherms to ongoing environmental changes.

Latitude shapes diel patterns in insect biodiversity

The writings of naturalists from two centuries past are brimming with accounts of the stark differences in the kinds and numbers of organisms encountered during the day and night as well as between the tropical and temperate zones. However, only recently have ecologists begun to systematically explore the geographic variation in the diel activity patterns of species on Earth. Examining data from 60 insect communities distributed globally, I find that the proportion of nocturnal species in a community declines from a peak of 36% at the equator to 8% at 60° latitude, while the proportion of diurnal species shows no significant trend. By contrast, the proportion of cathemeral (day- and night-active) species in a community increases poleward from 18% to 68% along the same gradient. These latitudinal trends in the partitioning of diel activity time among co-occurring insect species in communities broadly reflect previously documented biogeographic patterns in the global distributions of vertebrate species occupying different temporal niches. Since diel activity patterns shape insect community dynamics, uncovering their mechanistic basis and the roles of factors such as temperature, light and biotic interactions is vital for curbing insect declines in the Anthropocene.

The jumping performance of two Eleutherodactylus frog species: the effect of temperature

This study was undertaken to understand the species-specific response and the effect of changes in ambient temperature on the jumping performance of two congeneric tropical frog species, environmental specialist Eleutherodactylus wightmanae and environmental generalist Eleutherodactylus coqui, obtained from three distinct populations across their east-west longitudinal range in Puerto Rico. Three environmental temperatures currently experienced in their natural habitat were selected for treatments: 18 °C, 21 °C, and 24 °C. Jumping performance was determined by the average distance traveled per jump and the average speed per jump based on three consecutive jumps. A significant increase in distance per jump was observed in both species with the temperature treatment of 24 °C, resulting in the longest jump. On average, the specialist Eleutherodactylus wightmanae outperformed the generalist Eleutherodactylus coqui, but the effect was largely affected by temperature treatment and location. At a population level, individuals of both species obtained from the Toro Negro Forest jumped farther than individuals from Maricao and Cayey. Speed per jump was not affected by temperature treatments; instead, differences in speed were observed at the population (i.e. locality) and species level. Individuals of Eleutherodactylus coqui obtained from the Cayey Forest were significantly slower than all other sites in all treatments. In contrast, individuals of Eleutherodactylus wightmanae from the Maricao Forest were slowest in all treatments. The study provides evidence of the species-specific response to increases in temperature and the local adaptation capabilities and thermal plasticity observed across the longitudinal range for two frog species of Puerto Rico. The study also reinstates multifactorial aspects concerning anuran physiology and how biotic conditions affect their performance.

Future climate change facilitates the herb drought-tolerant species distribution than woody species

Drought-tolerant species play a crucial role in maintaining ecosystem services in arid and semi-arid regions wherein subject to rapid climate change. However, how future climate change affect the distribution of drought-tolerant plants with different growth forms (e.g., herb and woody) remains largely unknown. Here, we used the MaxEnt model to simulate the potential species distribution under current conditions, and predicted the future species distribution of 82 common drought-tolerant plants in China under two time periods (2041-2060 and 2081-2100) and three climate change scenarios (SSP126, SSP245 and SSP585) in the future. We found that the western and northern regions of China are hotspots for drought-tolerant plant distribution. Compared with other predictors, aridity index (AI) explained the largest portion of variation (45%) in the distribution patterns of drought-tolerant plant plants. Climate change would change the distribution of drought-tolerant plants, with more than 50% of the species showing a trend of shrinking ranges in China. For both herb and woody plants, the highest turnover values were observed under SSP585 for the period 2081-2100, reaching 37.67% and 29.08%, respectively. Our results highlighted that herb and woody plants respond differently to climate change stresses, with herb plants projected to greatly expand their ranges in the future. These insights are vital for evaluating the impacts of climate change on biodiversity and informing the development of effective adaptation strategies.

Diets shape thermal responses in Chinese giant salamanders by altering liver metabolism

Diet can influence the thermal performance of ectotherms, providing potential strategies for biological conservation in the context of global warming. The endangered Andrias davidianus is susceptible to heat stress due to energy deficiency in the liver when fed a worm-based diet rich in carbohydrates. A fish-based diet, rich in protein and lipids, improves their thermal performance, but the underlying physiological mechanisms remain unclear. In this study, we used metabolomics and metagenomics to examine the combined effects of temperature (15, 20, and 25°C) and diet (fish-based and worm-based) on liver metabolism and gut microbiota. Our results show that both temperature and diet shape liver metabolism, with several vital metabolic pathways (e.g., TCA cycle and sulfate metabolism) regulated by their combined effects. Notably, diet-dependent thermal responses in energy metabolism were observed, with fish-fed salamanders exhibiting a marked upregulation of the TCA cycle intermediates under heat stress, a response absent in worm-fed individuals. Given the role of TCA cycle in heat susceptibility of A. davidianus, these findings suggest that the TCA cycle likely mediates the interactive effects of temperature and diet on thermal performance. We then examined whether the gut microbiota is also a target of interactive effects or a mediator of the diet's influence on liver metabolism. While both temperature and diet shape microbiota composition, functional shifts occur only in response to temperature, indicating that the microbiota is not a major link between diet and liver metabolism. However, several bacterial groups (e.g., Thiosulfatimonas and Alcanivorax), jointly regulated by temperature and diet, correlate with liver metabolites, suggesting alternative, function-independent pathways through which dietary-related microbial changes may influence liver metabolism and even thermal tolerance. Overall, this study provides molecular insights into the dietary modulation of thermal performance in A. davidianus and highlight the potential of dietary microbial management strategies for amphibian conservation.

Temperature Effects on the Survival and Oviposition of an Invasive Blow Fly Chrysomya rufifacies Macquart (Diptera: Calliphoridae)

The globally increased severity and frequency of elevated temperatures are altering native species' geographic distributions and local abundances while also increasing the invasion of new areas by exotic species. These distributional shifts have affected native species. Through two experiments, we investigated the effects of temperature on the survival and oviposition of the hairy maggot blow fly Chrysomya rufifacies (Macquart), a highly competitive and predatory invasive blow fly of ecological, economic, and forensic importance. In our first experiment, we exposed mixed-sex colonies of C. rufifacies to a given temperature (10-45.0 °C) for 24 h. High survival (≥90%) was observed from 10 to 40 °C, with moderate mortality at 42.5 °C (29.2%) and high mortality at 43.5 °C (75.4%). All flies died when exposed to 44.5 or 45.0 °C for 24 h. Oviposition occurred from 22.5 to 42.5 °C, with the greatest occurrences (100%) at 30 and 35 °C and the greatest number of eggs (2035) occurring at 30 °C. Although oviposition occurred from 22.5 to 42.5 °C, egg viability was only observed from 22.5 to 37.5 °C. Thus, C. rufifacies has distinct thermal limits for survival, and oviposition may exhibit a bet-hedging strategy in response to temperature exposure. In our second experiment, we assessed the effects of an acute heat shock on C. rufifacies oviposition performance. Adult virgins (males and females) were exposed to 25.0 °C, 42.0 °C, or 44.0 °C for 1 h, and then maintained at ~25 °C in mixed-sex colonies for 14 d. Pre-breeding heat exposure had no effect on male or female reproductive success, except for females exposed to 44.0 °C. Females exposed to this temperature before breeding oviposited sooner (2.5 ± 0.0 d, 37.5% decrease), more frequently (0.5 ± 0.4, 33.3% increase), and produced more eggs (10,772.9 ± 2258.6 eggs, 73.3% increase) than female flies exposed to 25 °C. The combined results show that C. rufifacies survives exposures up to 43.5 °C, successfully oviposits up to 37.5 °C, and accelerates both oviposition timing and intensity following brief exposure to near upper lethal temperatures (44.0 °C), potentially provides C. rufifacies a competitive advantage over native calliphorids in warming environments.

Climate-induced shifts in crocodile body temperature impact behavior and performance

The increase of energy in the climate system caused by anthropogenic climate change is expected to disrupt predictable weather patterns and result in greater temperature extremes.1,2 As a result of these climate shifts, El-Niño Southern Oscillation (ENSO), which drives predictable periods of hot/dry and cool/wet across the Pacific, is expected to increase in variability and magnitude.3 These changes will significantly impact ectotherms, whose performance across a range of behaviors is dependent on local environmental temperatures.4 As such, we must understand the way individuals experience climate conditions and how changes in their body temperature (Tb), whether through climate or modification of their thermoregulatory mechanisms,5 affect their performance. Laboratory studies have shown that estuarine crocodile (Crocodylus porosus) diving and swimming performance is reduced above 32°C-33°C,6,7,8 temperatures commonly exceeded across their natural range. By monitoring Tb and diving activity in 203 free-ranging estuarine crocodiles over 15 years, we show that the Tb of crocodiles has increased alongside rising air temperatures since 2008, reflecting the climatic shifts caused by the ENSO cycle. As ambient temperatures rose, crocodiles experienced more days close to critical thermal limits (32°C-33°C), at which temperatures the duration of dives was reduced and the prevalence of active cooling behavior was elevated. This study demonstrates that crocodiles are susceptible to multi-year fluctuations in ambient temperature, which requires them to undertake concomitant changes in behavior. They are already close to their physiological thermal limit, but the impact of future predicted rises in temperature remains unknown.

How Air Temperature and Solar Radiation Impact Life History Traits in a Wild Insect

Ectotherms are essential components of all ecosystems. They rely on external heat sources like air temperature and solar radiation to regulate their body temperature and optimise life history traits. Climate change, by altering air temperature and cloud cover, will likely impact these processes. To examine how air temperature and shade influence terrestrial insects, we reared nymphs of the field cricket (Gryllus campestris) at high (mean air temperature 13.4°C) and low (mean air temperature 9.6°C) sites in northern Spain, with partially shaded and unshaded treatments at each site. We tested for local adaptation to these climate variables by rearing nymphs from high and low altitude genetic lineages in all treatment combinations. Development time was significantly longer (on average 10 days) at low air temperature but was unaffected by a 40% increase in shade, suggesting crickets compensate for reduced sun exposure in shaded environments and may forgo some opportunities to gain energy from the sun in unshaded environments. Adult mass was affected by an interaction between shade and air temperature. At low air temperature, shaded crickets had higher mass (on average + 0.06 g) than unshaded crickets, whereas at high air temperature, shaded crickets had lower mass than unshaded crickets (on average - 0.08 g). This indicates that changes in cloud cover will impact insects differently in warmer and cooler parts of their range. We found no evidence for local adaptation in either development time or mass, suggesting these traits are not strongly differentiated between populations from high and low altitude environments. Our findings highlight the importance of considering both air temperature and solar radiation when predicting climate change impacts on insects. Shifts in temperature and cloud cover may have complex and region-specific effects on these vital ecosystem components.

Heat stress effects on offspring compound across parental care

Heatwaves associated with climate change threaten biodiversity by disrupting behaviours like parental care. While parental care may buffer populations from adverse environments, studies show mixed results, possibly due to heat stress affecting different care components. We investigated how heat stress impacts parental care and offspring performance in the burying beetle Nicrophorus nepalensis under control (17.8°C) and heat stress (21.8°C) conditions. We focused on two critical periods: pre-hatching care (carcass preparation) and post-hatching care (offspring provisioning). To disentangle the vulnerability of these parental care components to heat stress, we reciprocally transferred carcasses prepared under control or heat stress to females breeding under both conditions. Heatwaves affecting only one care period did not alter reproduction, but when both pre- and post-hatching periods experienced heatwaves, reproductive success declined. Females exhibited higher energy expenditure during provisioning, evidenced by greater body mass loss. Notably, heat stress had long-lasting effects on offspring via carcass preparation, resulting in smaller adult size and higher mortality. These results highlight the complexity of environmental stressors on parental care, suggesting that different care components may respond differently to heat stress, and thus need to be examined separately to better understand how parental care responds to, and buffers against, temperature stress.

Vulnerability of amphibians to global warming

Amphibians are the most threatened vertebrates, yet their resilience to rising temperatures remains poorly understood1,2. This is primarily because knowledge of thermal tolerance is taxonomically and geographically biased3, compromising global climate vulnerability assessments. Here we used a phylogenetically informed data-imputation approach to predict the heat tolerance of 60% of amphibian species and assessed their vulnerability to daily temperature variations in thermal refugia. We found that 104 out of 5,203 species (2%) are currently exposed to overheating events in shaded terrestrial conditions. Despite accounting for heat-tolerance plasticity, a 4 °C global temperature increase would create a step change in impact severity, pushing 7.5% of species beyond their physiological limits. In the Southern Hemisphere, tropical species encounter disproportionally more overheating events, while non-tropical species are more susceptible in the Northern Hemisphere. These findings challenge evidence for a general latitudinal gradient in overheating risk4-6 and underscore the importance of considering climatic variability in vulnerability assessments. We provide conservative estimates assuming access to cool shaded microenvironments. Thus, the impacts of global warming will probably exceed our projections. Our microclimate-explicit analyses demonstrate that vegetation and water bodies are critical in buffering amphibians during heat waves. Immediate action is needed to preserve and manage these microhabitat features.

Plasticity in mosquito size and thermal tolerance across a latitudinal climate gradient

Variation in heat tolerance among populations can determine whether a species is able to cope with ongoing climate change. Such variation may be especially important for ectotherms whose body temperatures, and consequently, physiological processes, are regulated by external conditions. Additionally, differences in body size are often associated with latitudinal clines, thought to be driven by climate gradients. While studies have begun to explore variation in body size and heat tolerance within species, our understanding of these patterns across large spatial scales, particularly regarding the roles of plasticity and genetic differences, remains incomplete. Here, we examine body size, as measured by wing length, and thermal tolerance, as measured by the time to immobilisation at high temperatures ("thermal knockdown"), in populations of the mosquito Aedes sierrensis collected from across a large latitudinal climate gradient spanning 1300 km (34-44° N). We find that mosquitoes collected from lower latitudes and warmer climates were more tolerant of high temperatures than those collected from higher latitudes and colder climates. Moreover, body size increased with latitude and decreased with temperature, a pattern consistent with James' rule, which appears to be a result of plasticity rather than genetic variation. Our results suggest that warmer environments produce smaller and more thermally tolerant populations.

Climate Warming Increases the Voltinism of Pine Caterpillar (Dendrolimus spectabilis Butler): Model Predictions Across Elevations and Latitudes in Shandong Province, China

The pine caterpillar (Dendrolimus spectabilis Bulter, Lepidoptera: Lasiocampidae) is a destructive insect threatening forest communities across Eurasia. The pest is polyvoltine, and under global warming, more favorable temperatures can lead to additional generations. Here, we simulated the pine caterpillar voltinism under current and future climatic scenarios based on insect thermal physiology and cumulative growing degree day (CGDD) model. Subsequently, we revealed the future change patterns of the voltinism along elevational and latitudinal gradients. The results showed that both CGDD and pine caterpillar voltinism are increasing. The current voltinism of pine caterpillar ranges from 1.26 to 1.56 generations (1.40 ± 0.07), with an increasing trend of 0.04/10a. Similar trends are expected to continue under the future climate scenarios, with values of 0.01/10a, 0.05/10a, 0.07/10a, and 0.09/10a for the SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. At the elevation and latitudinal gradients, voltinism increases across all ranges, peaking at 500-1000 m and latitudes of 34-34.5° N. This study highlights that the increase in voltinism is not limited to low-elevation and -latitude regions but is predicted across various elevations and latitudes. These findings can enhance our understanding of how climate change affects pine caterpillar voltinism and contribute to forest pest management strategies, although this study assumes a linear relationship between temperature and voltinism, without considering other ecological factors.

Variability in spruce beetle (Coleoptera: Curculionidae, Scolytinae) adult diapause and evidence for oocyte development prior to winter in a Colorado population

Diapause regulates seasonal insect life cycles and may be highly variable within and among populations due to genetic and environmental variability. Both types of variation may influence how populations respond plastically or evolutionarily to changing climates. We assessed diapause variability in spruce beetle Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae, Scolytinae), a major forest pest whose life cycle timing is regulated by both prepupal and adult diapauses. Using mating studies and ovary dissections, we tested for variability in adult diapause within and between collection sites in Colorado and Wyoming, USA. Ovary morphology suggested that most females from both sites enter diapause prior to egg formation (oogenesis) when reared at warm temperatures. Though previous studies suggested that adult diapause is obligate, we found that a small proportion of females from both populations terminated diapause without winter chilling in the lab. Moreover, we found that most female beetles sampled at the Colorado field site had mature ovaries relatively early in the fall, suggesting that transient exposure to low temperatures may potentiate pre-winter reproductive development. Adult diapause may act primarily as a block to prevent offspring production late in the season but not necessarily as an overwintering phenotype. Overall, our data do not suggest imminent life cycle shifts mediated by adult diapause, but if the observed variability is heritable, diapause regulation may evolve in response to changing environmental conditions.

Physiological and morphological traits affect contemporary range expansion and implications for species distribution modelling in an amphibian species

Species range shifts due to climate alterations have been increasingly well-documented. Although amphibians are one of the most sensitive groups of animals to environmental perturbations due to climate change, almost no studies have offered evidence of poleward distribution shifts in this taxon in response to climate warming. Range shifts would be facilitated by variation in traits associated with the ability of species to persist and/or shift their range in the face of climate change, but the extent and consequences of intraspecific variation in these traits is unclear. We studied the role of intraspecific variation in the ongoing range shift of green treefrogs (Hyla cinerea) in response to climate change. We explored factors that are often associated with range shifts to test the hypothesis that there are differences in these traits between recently range-expanded and nearby historical populations. We then tested the consequences of intraspecific variation for modelling climate-induced range shifts by comparing species distribution models (SDMs) that used as input either data from the entire species range or separate inputs from 'subpopulations' corresponding to the historical range or the recently expanded range. We expected that building a separate SDM for each population would more accurately characterize the species range if historical and expanded populations differed in traits related to their response to climate. We found that critical thermal minimum decreased and thermal breadth increased with latitude, but the effect of latitude was significantly stronger for expanded populations compared to historical populations. Additionally, we found that individuals from expanded populations had longer leg lengths when compared to their historical counterparts. Finally, we found higher model accuracy for one of the population-level SDMs than the species-level SDM. Our results suggest that thermal tolerance and dispersal morphologies are associated with amphibian distributional shifts as these characteristics appear to facilitate rapid range expansion of a native anuran. Additionally, our modelling results emphasize that SDM accuracy could be improved by dividing a species range to consider potential differences in traits associated with climate responses. Future research should identify the mechanisms underlying intraspecific variation along climate gradients to continue improving SDM prediction of range shifts under climate change.

Untangling the Complexity of Climate Change Effects on Plant Reproductive Traits and Pollinators: A Systematic Global Synthesis

Climate change is expected to affect the morphological, physiological, and life-history traits of plants and animal pollinators due to more frequent extreme heat and other altered weather patterns. This systematic literature review evaluates the effects of climate change on plant and pollinator traits on a global scale to determine how species responses vary among Earth's ecosystems, climate variables, taxonomic groups, and organismal traits. We compiled studies conducted under natural or experimental conditions (excluding agricultural species) and analyzed species response patterns for each trait (advance vs. delay or no change for phenology, decrease vs. increase or no change for other traits). Climate change has advanced plant and animal phenologies across most Earth's biomes, but evidence for temporal plant-pollinator mismatches remains limited. Flower production and plant reproductive success showed diverse responses to warming and low water availability in Alpine and Temperate ecosystems, and a trend for increased or neutral responses in Arctic and Tropical biomes. Nectar rewards mainly experienced negative effects under warming and drought across Alpine and Temperate biomes, but scent emissions increased or changed in composition. Life form (woody vs. nonwoody species) did not significantly influence trait response patterns to climate change. Pollinator fecundity, size, life-history, developmental, and physiological traits mostly declined with warming across biomes; however, animal abundance and resource acquisition traits showed diverse responses. This review identified critical knowledge gaps that limit our understanding of the impacts of climate change, particularly in tropical/subtropical biomes and southern latitudes. It also highlights the urgent need to sample across a greater range of plant families and pollinator taxa (e.g., beetles, wasps, vertebrates). The diversity of climate change effects should be assessed in the context of other anthropogenic drivers of global change that threaten critically important pollination interactions.

Leaf Temperatures in an Indian Tropical Forest Exceed Physiological Limits but Durations of Exposures Are Currently Not Sufficient to Cause Lasting Damage

Increasing temperatures in the tropics will reduce performance of trees and agroforestry species and may lead to lasting damage and leaf death. One criterion to determine future forest resilience is to evaluate damage caused by temperature on Photosystem-II (PSII), a particularly sensitive component of photosynthesis. The temperature at which 50% of PSII function is lost (T50) is a widely used measure of irreversible damage to leaves. To assess vulnerability to high temperatures, studies have measured T50 or leaf temperatures, but rarely both. Further, because extant leaf temperature records are short, duration of exposure above thresholds like T50 has not been considered. Finally, these studies do not directly assess the effect of threshold exceedance on leaves. To understand how often, and how long, leaf temperatures exceed critical thresholds, we measured leaf temperatures of forest and agroforestry species in a tropical forest in the Western Ghats of India where air temperatures are high. We quantified species-specific physiological thresholds and assessed leaf damage after high-temperature exposure. We found that leaf temperatures already exceed T50. However, continuous exposure durations above critical thresholds are very skewed with most events lasting for much less than 30 min. As T50 was measured after a 30-min exposure, our results suggest that threshold exceedances and exposure durations for lasting damage are currently not reached and will rarely be reached if maximum air temperatures increase by 4°C. Consistent with this, we found only minor indications of heat damage in the forest species. However, there were indications of heat-induced reduction in PSII function and damage in the agroforestry leaves which have lower T50. Our findings suggest that, for forest species, while high-temperature thresholds may be surpassed, durations of exposure above thresholds remain short, and therefore, are unlikely to lead to irreversible damage and leaf death, even under 4°C warming.

Wolbachia-based mosquito control: Environmental perspectives on population suppression and replacement strategies

Mosquito-borne diseases pose a significant threat to global health, and traditional mosquito control methods often fall short of effectiveness. A promising alternative is the biological control strategy of transinfecting mosquitoes with Wolbachia, a bacterium capable of outcompeting harmful pathogens and reducing the ability of mosquitoes to transmit diseases. However, Wolbachia infections are sensitive to abiotic environmental factors such as temperature and humidity, which can affect their densities in mosquitoes and, consequently, their ability to block pathogens. This review evaluates the effectiveness of different Wolbachia strains transinfected into mosquitoes in reducing mosquito-borne diseases. It explores how Wolbachia contributes to mosquito population control and pathogen interference, highlighting the importance of mathematical models in understanding Wolbachia transmission dynamics. Additionally, the review addresses the potential impact on arboviral transmission and the challenges posed by environmental fluctuations in mosquito control programs.

Risk-sensitive foraging in a tropical lizard

Foraging opportunities can be unpredictable. When foragers face a choice between resources that vary in predictability, foraging decisions not only depend on the profitability of food but also on their physiological state. This risk-sensitive foraging approach, in which animals take greater foraging risks when starving, remains relatively untested in reptiles compared with other taxa. We tested the risk-sensitive foraging theory in the tropical lizard, Psammophilus dorsalis, by manipulating energy budgets (satiated versus 48 h starved) and measuring foraging preferences for options that differed in rewards: constant (two mealworms) versus variable (zero or four mealworms). We found that satiated lizards were risk averse to variability in reward amounts and chose the constant food option more frequently than the variable option. In contrast, starved lizards were risk-prone and chose the variable reward option more often than the constant one. At the end of foraging trials, these strategies resulted in both starved and satiated groups achieving similar net resource gains. As new support for risk-sensitive foraging in a tropical reptile species, these results provide insight into how resource uncertainty influences foraging strategies. For lizards in the tropics, which have high-energy requirements year-round, risk-sensitive foraging could be an effective strategy in stochastic environments.

Environmental Variability Shapes Life History of the World's Birds

Theory suggests life history plays a key role in the ability of organisms to persist under fluctuating environmental conditions. However, the notion that environmental variability has shaped the distribution of life history traits across large spatial and taxonomic scales has gone largely untested using empirical data. Synthesising a collection of data resources on global climate, species traits, and species ranges, we quantified the role that environmental variability over time has played in shaping pace of life across the world's non-migratory, non-marine bird species (N = 7477). In support of existing theory, we found that species that experience high inter-annual temperature variability tended to have a slower pace of life, while the opposite was true for high intra-annual temperature variability. The effect of precipitation variability was less pronounced and more uncertain. These observed patterns were apparent despite the vastly different ecologies of our study species and evidence of strong phylogenetic constraint. Additionally, we highlight the importance of contextualising rates of environmental change in terms of the historical variability of environmental systems and species' pace of life. Species experiencing higher rates of relative environmental change, in terms of standard deviations per generation, may be most susceptible to climate change.

A review of short-term weather impacts on honey production

Beekeeping is an exceptionally weather-sensitive agricultural field. Honey production and pollination services depend on the complex interaction of plants and bees, both of which are impacted by short-term weather changes. In this review, classical and recent research is collected to provide an overview on short-term atmospheric factors influencing honey production, and the optimal and critical weather conditions for bee activity. Bee flight can be directly obstructed by precipitation, wind, extreme temperatures and also air pollution. Bees generally fly within a temperature range of 10-40 °C, with optimal foraging efficiency occurring between 20 and 30 °C. Wind speeds exceeding 1.6-6.7 m/s can reduce foraging efficiency. Additionally, bee activity is significantly correlated with temperature, relative humidity and solar radiation, factors which influence nectar production. Optimal conditions for nectar collection typically occur in the morning and early afternoon hours with mild and moist weather. The diurnal nectar collection habit of bees adjusts to the nectar production of individual plant species. Extreme weather occurring in the sensitive hours is noticeable both in the nectar production of plants and in the activity of bees, thus in the honey yield. Understanding the impact of weather on honey bees is crucial in the management and planning of honey production. This review highlights the importance of studying these interactions to better adapt beekeeping practices to changing environmental conditions.

Altitudinal variation in thermal vulnerability of Qinghai-Tibetan Plateau lizards under climate warming

The survival of ectotherms worldwide is threatened by climate change. Whether increasing temperatures increase the vulnerability of ectotherms inhabiting temperate plateau areas remains unclear. To understand altitudinal variation in the vulnerability of plateau ectotherms to climate warming, Qinghai toad-headed lizards (Phrynocephalus vlangalii) were subjected to semi-natural enclosure experiments with simulated warming at high (2,600 m) and superhigh (3,600 m) elevations of the Dangjin Mountain, China. Our results revealed that the thermoregulatory effectiveness and warming tolerance (WT) of the toad-headed lizards were significantly affected by climate warming at both elevations, but their thermal sensitivity remained unchanged. After warming, the thermoregulatory effectiveness of lizards at superhigh elevations decreased because of the improved environmental thermal quality, whereas that of lizards at high-elevation conditions increased. Although the body temperature selected by high-elevation lizards was also significantly increased, the proportion of their active body temperature falling within the set-point temperature range decreased. This indicates that it is difficult for high-elevation lizards to adjust their body temperatures within a comfortable range under climate warming. Variations in the WT and thermal safety margin (TSM) under climate warming revealed that lizards at the superhigh elevation benefited from improved environmental thermal quality, whereas those at the high elevation originally on the edge of the TSM faced more severe threats and became more vulnerable. Our study highlights the importance of thermal biological traits in evaluating the vulnerability of ectotherms in temperate plateau regions.

High Microsatellite but No Mitochondrial DNA Variation in an Invasive Japanese Mainland Population of the Parasitoid Wasp Melittobia sosui

Invasive populations are predicted to have reduced genetic diversity due to bottleneck events. The parasitoid wasp Melittobia sosui was previously identified only in the subtropical area of the southern Japanese islands and Taiwan but was recently found in the temperate area of the Japanese mainland. The distribution of this species may have recently expanded northward due to factors such as climatic events and global warming. The population genetics of both the native and invasive regions were investigated using mitochondrial and nuclear microsatellite DNA. As expected, mitochondrial variation was observed in the native region but not in the invasive region, which had only one haplotype. However, the two regions exhibited similar levels of microsatellite variation, and an average of 43% and 38% of alleles were uniquely found in the native and invasive populations, respectively. The difference in genetic variation between mitochondrial and microsatellite DNA in the invasive populations may be explained by the faster mutation rate of microsatellites, as well as the population structure of Melittobia, in which the subdivision into small inbreeding lineages may facilitate the accumulation of mutations. The high proportion of private alleles suggests that the mainland population diverged from the native populations at least 100 years ago, ruling out the possibility that the mainland population was established recently. The present study suggests that M. sosui might have already existed on the mainland but at a low frequency or that the mainland population was derived from a ghost population that diverged from the native populations more than 100 years ago.

Assessing the potential for predator-prey interactions in mesofaunal arthropod communities through temperature dependence of locomotion

Thermal performance curves (TPCs) have become an important part of the thermal biologists' toolbox in understanding how organisms may respond to temperature variation. The aim of this study was to investigate how temperature affects the locomotion of soil arthropods (Collembola and Acari), and explore how these responses might influence the potential for predator-prey interactions under different environmental conditions. Locomotion-based thermal performance curves of four species of Acari and three species of Collembola were estimated across seven test temperatures through automated tracking of individuals. Acari (predators) generally exhibited broader thermal tolerances compared to Collembola (prey), with overlapping thermal optima observed for some species, such as Parasitus sp. and Ceratophysella cf. gibbosa. However, differences in maximum thermal limits could influence predator-prey dynamics under warmer conditions. There were no significant effects of temperature on distance traveled or maximum walking speed for most species (Folsomina sp. p = 0.21, Ceratophysella cf. gibbosa p = 0.55, Mucrosomia sp. p = 0.36), with subclass-level analyses also showing no significant effects for Acari (p = 0.6) or Collembola (p = 0.96). Among Acari, Linopodes sp. exhibited a clear TPC, peaking at 30 °C (175 mm/s), while Parasitus sp. and Ceratophysella cf. gibbosa displayed broad thermal tolerances, with the temperature at which performance is maximized (Rmax) near 20 °C and 30 °C, respectively. Among the Acari species tested, Linopodes sp. and Parasitus sp. did show typical TPCs. Among Collembola, Folsomina sp. and Ceratophysella cf. gibbosa showed typical TPCs. These sit-and-wait predators with jump escaping prey groups are likely to be poorly captured by a TPC approach, suggesting other functional traits such as feeding rates, handling times and/or digestion efficiency should be employed in the future to better characterize temperature-dependent interactions.

Climate effects on honey bees can be mitigated by beekeeping management in Kenya

In recent decades, worldwide concerns about the health of honey bees motivated the development of surveys to monitor the colony losses, of which Sub-Saharan Africa has had limited representation. In the context of climate change, understanding how climate affects colony losses has become fundamental, yet literature on this subject is scarce. For the first time, we conducted a survey to estimate the livestock decrease of honey bee colonies in Kenya for the year 2021-2022 to explore the effects of environmental conditions, such as temperature and precipitation, on livestock decrease. We define "livestock decrease" from the beekeeper's perspective, including dead colonies but also, in the specific context of the tropics, the colonies that absconded from the apiary. A total of 589 beekeepers from a variety of areas participated in the survey. Kenyan beekeepers had an average of 36.6% livestock decrease in 2021-2022, with higher decreases during the dry and hot (31.9%) than during the wet and cold season (20.2%). We found that livestock decreases were more important with temperature for both dry and hot and wet and cold seasons. Interestingly, we found that precipitation mitigated temperature effects on livestock decrease for both seasons. Finally, we found that beekeepers practicing water supplementation had up to 10% less livestock decrease during the dry and hot season than those that did not, suggesting it to be a relevant adaptive strategy to mitigate livestock decrease. It is worth noting that beekeepers can renew their stock by trapping swarms, yet this represents a cost in time and baiting materials. Based on climate change projections, we predicted that annual and seasonal livestock decrease would remain in the same range at horizon 2050 and horizon 2100. These results pinpoint difficulties in maintaining livestock for beekeepers in Kenya and provide clues for strategies to pursue in the context of climate change.

Thermal variation influences the transcriptome of the major malaria vector Anopheles stephensi

The distribution and abundance of ectothermic mosquitoes are strongly affected by temperature, but mechanisms remain unexplored. We describe the effect of temperature on the transcriptome of Anopheles stephensi, an invasive vector of human malaria. Adult females were maintained across a range of mean temperatures (20 °C, 24 °C and 28 °C), with daily fluctuations of +5 °C and -4 °C at each mean temperature. Transcriptomes were described up to 19 days post-blood meal. Of the >3100 differentially expressed genes, we observed shared temporal expression profiles across all temperatures, suggesting their indispensability to mosquito life history. Tolerance to 20 and 28 ( + 5°C/-4°C) was associated with larger and more diverse transcriptomes compared to 24 ( + 5 °C/-4 °C). Finally, we identified two distinct trends in gene expression in response to blood meal ingestion, oxidative stress, and reproduction. Our work has implications for mosquitoes' response to thermal variation, mosquito immune-physiology, mosquito-malaria interactions and the development of vector control tools.

Life-history adaptation under climate warming magnifies the agricultural footprint of a cosmopolitan insect pest

Climate change is affecting population growth rates of ectothermic pests with potentially dire consequences for agriculture and global food security. However, current projection models of pest impact typically overlook the potential for rapid genetic adaptation, making current forecasts uncertain. Here, we predict how climate change adaptation in life-history traits of insect pests affects their growth rates and impact on agricultural yields by unifying thermodynamics with classic theory on resource acquisition and allocation trade-offs between foraging, reproduction, and maintenance. Our model predicts that warming temperatures will favour resource allocation towards maintenance coupled with increased resource acquisition through larval foraging, and the evolution of this life-history strategy results in both increased population growth rates and per capita host consumption, causing a double-blow on agricultural yields. We find support for these predictions by studying thermal adaptation in life-history traits and gene expression in the wide-spread insect pest, Callosobruchus maculatus; with 5 years of evolution under experimental warming causing an almost two-fold increase in its predicted agricultural footprint. These results show that pest adaptation can offset current projections of agricultural impact and emphasize the need for integrating a mechanistic understanding of life-history evolution into forecasts of pest impact under climate change.

Climate change and the cost-of-living squeeze in desert lizards

Climate warming can induce a cost-of-living "squeeze" in ectotherms by increasing energetic expenditures while reducing foraging gains. We used biophysical models (validated by 2685 field observations) to test this hypothesis for 10 ecologically diverse lizards in African and Australian deserts. Historical warming (1950-2020) has been more intense in Africa than in Australia, translating to an energetic squeeze for African diurnal species. Although no net impact on Australian diurnal species was observed, warming generated an energetic "relief" (by increasing foraging time) for nocturnal species. Future warming impacts will be more severe in Africa than in Australia, requiring increased rates of food intake (+10% per hour active for diurnal species). The effects of climate warming on desert lizard energy budgets will thus be species-specific but potentially predictable.

Population Genomics Reveals Local Adaptation Related to Temperature Variation in Two Stream Frog Species: Implications for Vulnerability to Climate Warming

Identifying populations at highest risk from climate change is a critical component of conservation efforts. However, vulnerability assessments are usually applied at the species level, even though intraspecific variation in exposure, sensitivity and adaptive capacity play a crucial role in determining vulnerability. Genomic data can inform intraspecific vulnerability by identifying signatures of local adaptation that reflect population-level variation in sensitivity and adaptive capacity. Here, we address the question of local adaptation to temperature and the genetic basis of thermal tolerance in two stream frogs (Ascaphus truei and A. montanus). Building on previous physiological and temperature data, we used whole-genome resequencing of tadpoles from four sites spanning temperature gradients in each species to test for signatures of local adaptation. To support these analyses, we developed the first annotated reference genome for A. truei. We then expanded the geographic scope of our analysis using targeted capture at an additional 11 sites per species. We found evidence of local adaptation to temperature based on physiological and genomic data in A. montanus and genomic data in A. truei, suggesting similar levels of sensitivity (i.e., susceptibility) among populations regardless of stream temperature. However, invariant thermal tolerances across temperatures in A. truei suggest that populations occupying warmer streams may be most sensitive. We identified high levels of evolutionary potential in both species based on genomic and physiological data. While further integration of these data is needed to comprehensively evaluate spatial variation in vulnerability, this work illustrates the value of genomics in identifying spatial patterns of climate change vulnerability.

Clustered warming tolerances and the nonlinear risks of biodiversity loss on a warming planet

Anthropogenic climate change is projected to become a major driver of biodiversity loss, destabilizing the ecosystems on which human society depends. As the planet rapidly warms, the disruption of ecological interactions among populations, species and their environment, will likely drive positive feedback loops, accelerating the pace and magnitude of biodiversity losses. We propose that, even without invoking such amplifying feedback, biodiversity loss should increase nonlinearly with warming because of the non-uniform distribution of biodiversity. Whether these non-uniformities are the uneven distribution of populations across a species' thermal niche, or the uneven distribution of thermal niche limits among species within an ecological community, we show that in both cases, the resulting clustering in population warming tolerances drives nonlinear increases in the risk to biodiversity. We discuss how fundamental constraints on species' physiologies and geographical distributions give rise to clustered warming tolerances, and how population responses to changing climates could variously temper, delay or intensify nonlinear dynamics. We argue that nonlinear increases in risks to biodiversity should be the null expectation under warming, and highlight the empirical research needed to understand the causes, commonness and consequences of clustered warming tolerances to better predict where, when and why nonlinear biodiversity losses will occur.This article is part of the discussion meeting issue 'Bending the curve towards nature recovery: building on Georgina Mace's legacy for a biodiverse future'.