Adult Population Size Research Articles

On the aquatic phenology of sympatric crested and marbled newts (genus Triturus)

Abstract The large-bodied newts Triturus cristatus and T. marmoratus possess ranges that overlap in western France where they frequently share breeding ponds. I test the hypothesis that the aquatic phenology differs between them, as associated with a more aquatic and terrestrial life style respectively. Total adult population sizes were determined in spring in 13 experiments by the capture-mark-recapture methodology, followed by equivalent experiments in summer. Population sizes dropped by an order of magnitude on average whereas species frequencies changed in favour of T. cristatus, suggesting that T. marmoratus leaves the breeding site earlier than T. cristatus. Interspecies hybrids behaved like T. marmoratus. Descriptions are provided of other features (in ecology, morphology, demography, and colouration pattern) that support the different, aquatic versus terrestrial life styles of T. cristatus and T. marmoratus.

Safety assessment of high doses of vaporized oxalic acid on honey bee worker health and queen quality

IntroductionThe honey bee ectoparasitic mite, Varroa destructor, is one of the main causes of honey bee colony loss worldwide. Synthetic acaricides are the most commonly used strategy for varroa control, however, resistance to these acaricides has emerged. Consequently, the use of organic acids for varroa control is gaining more interest among beekeepers. For example, oxalic acid (OA) is a natural compound that has been shown to be an effective acaricide against varroa mites, however, the potential toxicity of OA to adult bees and queens is poorly understood. The objective of the study was to evaluate the toxicity of incremental doses of vaporized OA on honey bee workers and queens.MethodsWe exposed 32 colonies to incremental doses (0, 5, 10 or 20 g per colony) of vaporized OA once per week over four consecutive weeks and we monitored the acute and long-term toxicity. We investigated the short-term effects of OA administration by evaluating adult bee mortality, brood production, and population size. Next, we evaluated the long-term effects of OA application on both worker bees and queens. Regarding workers, we investigated their ability to rear new queens. As for queens, we measured acceptance, performance, and sperm quality.ResultsWe found that colonies treated with 20 g OA (20 times the label dose) had a statistically significant increase in worker bee mortality, with a non-significant, 23% decrease in brood relative to controls. No significant differences were observed in queen performance nor sperm quality.DiscussionWe found that repeated application of vaporized OA, at up to 20 times the label dose, had no significant short-term nor long-term, negative effects on colony or queen health, with the exception of a short-term increase in adult bee mortality in the 20 g OA-treated group. The results of this study support the safety of higher-than-label doses of OA for honey bee colonies. The observed increase in adult bee mortality in the 20 g OA dose group in this study suggests that OA doses should be maintained below 20 g per brood chamber.

Multiple events determine the distribution of fishes’ early life stages in the Abrolhos Bank, Southwestern Atlantic

Fluctuations in reef fish settlement and recruitment significantly impact local population dynamics and adult population size. We use light traps to evaluate reef fish settlement in inshore and offshore reefs in the Abrolhos Bank, in addition to the spatio-temporal distribution patterns, and environmental variables' influence. Data were collected from inshore and offshore reefs, and statistical analyses, including GLMs, PERMANOVA and nMDS, aimed to understand spatial-temporal species distribution patterns and the relationship between environmental variables. Results indicate greater species abundance and diversity offshore, influenced by winds, tides, and distance from shore, explaining 50% of larval patterns and highlighting the importance of spatial-temporal variations in early-life reef fish assemblages. However, several factors, including habitat type, quality, complexity, seascape configuration, and MPA location, may influence these patterns. Additionally, we provide evidence that commercially important species like Lutjanids use Abrolhos reef areas as nursery grounds.

Using Age-Stage Two-Sex Life Tables to Assess the Suitability of Three Solanaceous Host Plants for the Invasive Cotton Mealybug Phenacoccus solenopsis Tinsley.

Phenacoccus solenopsis Tinsley (Hemiptera: Coccomorpha: Pseudococcidae), the cotton mealybug, is an invasive polyphagous species that has been extending its geographic range, posing a conspicuous threat to many Mediterranean crops of economic importance. These include three species of Solanaceae, namely Solanum lycopersicum L. (tomato), Solanum tuberosum L. (potato) and Solanum melongena L. (eggplant) all of which are economically important worldwide. In this study, we used age-stage two-sex life tables to investigate the suitability of these three plant species as hosts for P. solenopsis and to calculate pest fitness, life history parameters and population projection parameters. All tested host plants that were suitable for the pest and eggplant host plant induced a higher fecundity (276.50 ± 10.78 eggs/female), net reproductive rate (R0) (243.32 ± 15.83 offspring/female) and finite rate of increase (λ) (1.18 ± 0.0043 day-1) and more extended adult longevity (males: 6.50 ± 0.34 days and females: 24.15 ± 0.50 days). Population growth predictions over a period of 90 days of infestation, commencing with an initial population of 10 eggs showed that adult population size was 674,551 on tomato, 826,717 on potato and 355,139 on eggplant. Our data on plant host preference of P. solenopsis will aid the development of appropriate management strategies and achieve successful control of this invasive pest in key Mediterranean crop systems.

A narrative review: suicide and suicidal behaviour in older adults.

Globally, suicide is a public health concern that claims the lives of many each year. The complex etiology and factors contributing to the risk of suicide make it hard to predict the likelihood of death by suicide. Suicide rates have been increasing over the past 25 years in patients aged 65 years and older, and with the expected increases in the size of the older adult population and the under-detection of suicide risk, these rates may continue to increase. To mitigate and attempt to limit this expected increase, it is important to understand the risk and protective factors of suicide in older adults. This narrative review focuses on individuals above the age of 65 and encompasses relevant peer-reviewed publications from the past 25 years to cover fatal and non-fatal suicidal behaviour. It summarizes several important risk factors for suicide and suicidal behaviors while considering how risk can be detected, assessed, prevented, and mitigated. Screening methods to detect suicide and depression in older adults were examined based on their effectiveness and suitability for use in this population. Lastly, the impacts of the COVID-19 pandemic on suicide rates in older adults were described.

Colonization of Piriformospora indica enhances rice resistance against the brown planthopper Nilaparvata lugens.

Piriformospora indica is an endophytic fungus that can promote the growth and confer resistance against diverse stresses in host plants by root colonization. However, the effects of P. indica colonization on improving plant resistance to insect pests are still less explored. The brown planthopper (BPH) Nilaparvata lugens is a serious monophagous pest that causes extensive damage to rice plants. Here, we aimed to evaluate the effects of P. indica colonization on rice resistance against BPH. The colonization of P. indica in rice roots resisted damage from BPH. Age-stage, two-sex life table analyses showed that feeding on P. indica-colonized rice plants affected BPH's female adult longevity, oviposition period, fecundity, population parameters and population size. BPH female adults feeding on P. indica-colonized plants excreted less honeydew. P. indica colonization remarkably increased the duration of np, N2, and N3 waveform, as well as the occurrences of N1 and N2, and decreased the duration of N4-b for BPH on rice plants. Meanwhile, the weight of BPH on the colonized plants was significantly lower than the control. In addition, the feeding and oviposition preferences of BPH to P. indica-colonized plants were reduced. qRT-RCR analyses revealed that P. indica colonization induced the expressions of jasmonic acid (JA)- and salicylic acid (SA)-related genes in rice plants. P. indica colonization can reduce BPH performance on rice plants with potential inhibitory effects on population growth. Collectively, these results support the potential for endophytically colonized P. indica as an effective strategy to improve insect resistance of crops. © 2024 Society of Chemical Industry.

Projections of functional dependence among the late middle-aged and older population from 2018-2048 in China: a dynamic microsimulation

BackgroundThe population of China is aging rapidly. However, the long-term trajectories of functionally dependent late middle-aged and older Chinese people are currently absent. The present study aimed to estimate the population size and proportion of late middle-aged and older adults with difficulties and dependence on activities of daily living (ADL) and instrumental activities of daily living (IADL) in China from 2018 to 2048.MethodsWe constructed a dynamic microsimulation model to project the population size and proportions of late middle-aged and older Chinese people who have difficulty and dependence in ADL and IADL from 2018-2048. The model was populated with a representative sample of the target population and allowed individual-level interaction between risk factors, diseases, and health outcomes. Analyses by socioeconomic subgroups were also conducted.ResultsAlmost 25% and 38% of late middle-aged and older people in China will become ADL- and IADL-dependent by 2048, respectively. Also, 17% of the target population will be severely ADL-disabled by 2048. The inequity in functional status across subgroups by sex, educational level, and urban/rural residency will become substantial.ConclusionsThe numbers and percentages of China's functionally difficult and dependent late middle-aged and older population will increase by magnitudes as of the mid-21st century, the pressure of which is compounded by its disproportionate distribution across subgroups. To alleviate the overwhelming challenge, efforts to improve the functional status of the underserved subpopulation should also be iterated.

A video monitoring and computational system for estimating migratory juvenile fish abundance in river systems

AbstractDiadromous fishes migrate between marine and fresh waters for reproduction. For anadromous species, which spawn in freshwater, improved access to freshwater spawning and nursery habitats and ability of juveniles to emigrate to the ocean may support population recovery. Despite the potentially enormous influence of early life stage survival on adult population size, managers and scientists have limited capacity to assess numbers of juvenile anadromous fishes leaving freshwater ecosystems. Such data are critical for evaluating reproductive success and habitat suitability and have been identified as a top priority in anadromous fish research and management. We developed a state‐of‐the‐art underwater video and computational system to collect videos to estimate abundances and migration timing for juvenile river herring (Alosa pseudoharengus; Alosa aestivalis). We collected continuous video in the Monument River (Bourne, Massachusetts, USA) from June to November 2017. We trained three types of neural network models to detect and count fish in video frames and evaluated model performance by comparing human counts to model outputs. Our top model assessed presence and absence (F1 = 87%) and counted fish (counting error 9.4%) with an accuracy comparable to human counters (F1 = 88%). Our system's capability to collect accurate counts of emigrating juveniles will provide critical information that could be related to the numbers of spawning adults, system‐specific productivity, and spawning and nursery habitat suitability. Both the video collection system and computational model may be transferrable to other sites and for other species where tracking juvenile emigration may inform management efforts.

Population parameters and conservation implications for one of the world's rarest marine fishes, the red handfish (Thymichthys politus).

Population estimates are required for effective conservation of many rare marine species, but can be difficult to obtain. The critically endangered red handfish (Thymichthys politus) is a coastal anglerfish known only from two fragmented populations in southeast Tasmania, Australia. It is at a high risk of extinction due to low numbers, loss of habitat, and the impacts of climate change. To aid conservation efforts, we provide the first empirical population size estimates of red handfish and investigate other important aspects of the species' life history, such as growth, habitat association, and movement. We surveyed both red handfish local populations via underwater visual census on scuba over 3 years and used photographic mark-recapture techniques to estimate biological parameters. In 2020, the local adult population size was estimated to be 94 (95% confidence interval [CI] 40-231) adults at one site, and 7 (95% CI 5-10) at the other site, suggesting an estimated global population of 101 adults. Movement of individuals was extremely limited at 48.5 m (± 77.7 S.D.) per year. We also found evidence of declining fish density, a declining proportion of juveniles, and increasing average fish size during the study. These results provide a serious warning that red handfish are likely sliding toward extinction, and highlight the urgent need to expand efforts for ex situ captive breeding to bolster numbers in the wild and maintain captive insurance populations, and to protect vital habitat to safeguard the species' ongoing survival in the wild.

The impact of healthcare system quality and economic factors on the older adult population: a health economics perspective.

This study investigates the influence of economic conditions, healthcare system capacity, and health-related variables on the proportion of the older adult population (Population ages 65 and above) in European Union countries. It aims to identify how factors such as GDP, unemployment, inflation, healthcare expenditure, hospital bed availability, and the prevalence of chronic diseases impact the aging demographic. This study explores the dynamic interactions and temporal relationships between economic stability, healthcare capacity, chronic disease prevalence, and demographic aging patterns. The research employs a mixed-method approach, utilizing System GMM and wavelet coherence analysis on panel data from 27 EU countries between 2000 and 2021. The findings reveal significant positive associations between economic prosperity and healthcare resources with the size of the older adult population. Increased GDP, efficient healthcare spending, and hospital bed availability are positively correlated with a larger older adult demographic. In contrast, high unemployment and inflation are linked to negative outcomes for the older adult population, reducing available resources and access to healthcare. Wavelet coherence analysis further uncovers how fluctuations in the prevalence of chronic diseases influence aging trends across different periods and frequencies. The study highlights the importance of integrated economic and healthcare policies to support the growing older adult population. Ensuring economic stability, enhancing healthcare infrastructure, and effectively managing chronic diseases are essential for improving quality of life and promoting sustainable aging in EU societies.

TECHNOLOGY AND OLDER ADULTS: BEST PRACTICES FOR ENHANCING USABILITY, ENGAGEMENT, AND COMMUNICATION

Abstract The massive growth in population aging has coincided with a time of continued fast-paced innovations in technology. Technology can be leveraged to support health, well-being, and quality of life in older adults with health, mobility, and cognitive issues and is a means of maintaining social engagement in later life. However, for technology to achieve its intended purpose, older adults must have access to and recognize the value of such products. Despite the sheer size of the older adult population, the field of Information Communications Technology (ICT), has long overlooked the perspectives of older adults with regard the design of ICT applications. ICT systems that fail to consider the diverse capabilities and attitudes of older adult users are likely to alienate a significant, growing segment of the population and will likely be underutilized. This presentation will review best practices to enhance older adults’ usability and engagement with technology, with an emphasis on user-centered design principles as well as innovative tools facilitating virtual ICT support and training (e.g., TeamViewer software) to provide older adults who have limited to no technology proficiency with the skills needed to navigate its use. Key takeaways from this presentation will include a greater understanding of the importance of design principles to enhance usability and adoption of ICT systems among older adults; means of increasing access and adoption of ICT applications; and how user feedback can be leveraged to inform adaptions to enhance the efficacy and acceptability of technology applications, and ultimately foster psychosocial well-being in older adults.

Carbohydrate nutrition associated with health of overwintering honey bees.

In temperate climates, honey bees rely on stored carbohydrates to sustain them throughout the winter. In nature, honey serves as the bees' source of carbohydrates, but when managed, beekeepers often harvest honey and replace it with cheaper, artificial feed. The effects of alternative carbohydrate sources on colony survival, strength, and individual bee metabolic health are poorly understood. We assessed the impacts of carbohydrate diets (honey, sucrose syrup, high-fructose corn syrup, and invert syrup) on colony winter survival, population size, and worker bee nutritional state (i.e., fat content and gene expression of overwintered bees and emerging callow bees). We observed a nonsignificant trend for greater survival and larger adult population size among colonies overwintered on honey compared to the artificial feeds, with colonies fed high-fructose corn syrup performing particularly poorly. These trends were mirrored in individual bee physiology, with bees from colonies fed honey having significantly larger fat bodies than those from colonies fed high-fructose corn syrup. For bees fed honey or sucrose, we also observed gene expression profiles consistent with a higher nutritional state, associated with physiologically younger individuals. That is, there was significantly higher expression of vitellogenin and insulin-like peptide 2 and lower expression of insulin-like peptide 1 and juvenile hormone acid methyltransferase in the brains of bees that consumed honey or sucrose syrup relative to those that consumed invert syrup or high-fructose corn syrup. These findings further our understanding of the physiological implications of carbohydrate nutrition in honey bees and have applied implications for colony management.

Novel grid‐based population estimates correlate with actual population sizes of the marsh fritillary (Euphydryas aurinia), while transect and larvae counts are less reliable

Abstract Established butterfly survey methods that are useful for monitoring species that are widely distributed and numerous may be less accurate for more rare species. We therefore need new monitoring approaches. We describe a plot‐based survey method, where butterflies or larvae nests are counted within 1‐ha grid cells. The aim was to compare this grid method with more traditional transect counts and evaluate both methods in relation to high‐quality capture–mark–release (CMR) population estimates (reflecting the ‘true’ population). We do this using data from a large population of the marsh fritillary butterfly in Sweden. Moreover, we followed the overall population trend from 2017 to 2021 for both adult butterflies and larvae. Results showed a higher detection probability using the grid method compared with transect counts, which for adult butterflies seem to be explained by time effort. Moreover, grid surveys of adult butterflies showed a clear significant relationship with the estimated ‘true’ population size from CMR, while transect counts did not. For larvae, both methods showed significant relationships with the estimated adult population size, but the grid method found 5.7 times more larvae. The overall population fluctuated significantly across years. In years with low densities, the transect method largely failed to detect the species. The grid method seems more reliable for detecting the marsh fritillary and for estimating its population size, and thus, tracking the population trend. We propose this novel method to be integrated into surveys and monitoring of biodiversity, especially when focusing on rare habitat specialists that are normally underrepresented in monitoring based on volunteer counts.

Advances in wildlife abundance estimation using pedigree reconstruction.

The conservation and management of wildlife populations, particularly for threatened and endangered species are greatly aided with abundance, growth rate, and density measures. Traditional methods of estimating abundance and related metrics represent trade-offs in effort and precision of estimates. Pedigree reconstruction is an emerging, attractive alternate approach because its use of one-time, noninvasive sampling of individuals to infer the existence of unsampled individuals. However, advances in pedigree reconstruction could improve its utility, including forming a measure of precision for the method, establishing required spatial sampling effort for accurate estimates, ascertaining the spatial extent of abundance estimates derived from pedigree reconstruction, and assessing how population density affects the estimator's performance. Using established relationships for a stochastic, spatially explicit simulated moose (Alces americanus) population, pedigree reconstruction provided accurate estimates of the adult moose population size and trend. Novel bootstrapped confidence intervals performed as expected with intensive sampling but underperformed with moderate sampling efforts that could produce abundance estimates with low bias. Adult population estimates more closely reflected the total number of adults in the extant population, rather than number of adults inhabiting the area where sampling occurred. Increasing sampling effort, measured as the proportion of individuals sampled and as the proportion of a hypothetical study area, yielded similar asymptotic patterns over time. Simulations indicated a positive relationship between animal density and sampling effort required for unbiased estimates. These results indicate that pedigree reconstruction can produce accurate abundance estimates and may be particularly valuable for surveying smaller areas and low-density populations.

Can spatial and temporal differences in fish assemblage structure inform conservation of an endangered sucker in a large western reservoir?

AbstractObjectiveConversion of lotic to lentic habitat after river impoundment can lead to habitat loss and threats from introduced species to native aquatic organisms. Some native species can persist in reservoirs despite these alterations. Some of the largest reservoirs in North America were constructed in the Colorado River basin and are used by endangered Razorback Sucker Xyrauchen texanus. This species successfully spawns in several reservoirs and recruits to adulthood in Lake Mead, whereas recruitment in other reservoirs and altered river habitats is limited or nonexistent. Hypothesized mechanisms for the general lack of recruitment include flow and habitat alteration as well as competition and predation from nonnative fishes.MethodsWe analyzed 16 years of netting data from Lake Mead to assess spatial and temporal patterns in fish assemblage structure and the size structure of Razorback Sucker across four sites.ResultThere was a substantial shift in assemblage structure across all sites after the establishment of Gizzard Shad Dorosoma cepedianum in 2010–2011 and an apparent decline in Threadfin Shad D. petenense. Captures of juvenile Razorback Sucker (<450 mm total length in Lake Mead) were higher at sites where overall fish abundance was also higher, suggesting that all fishes might be responding to similar spatial and temporal environmental variation. We identified differences in Razorback Sucker size structure that varied over time and among sites, largely driven by the presence of juvenile Razorback Sucker at some sites in some years.ConclusionRazorback Sucker was among the top‐10 most abundant species at all sites sampled, but assemblages were dominated by abundant nonnative fishes. Razorback Sucker continue to recruit in Lake Mead in the face of abundant and diverse nonnative fishes, but the adult population size remains relatively small (<1000). Further investigation of limiting factors will be necessary to understand which actions might be successful at improving recruitment conditions.

Depensation in fish recruitment driven by context-dependent interactions with another predator

Recruitment depensation describes elevated juvenile mortality with declining adult population size which can prevent or delay stock recovery. Understanding the factors influencing when a population undergoes depensation provides resource agencies with targets for management action. Using estimates of depensation from 28 walleye (Sander vitreus, Percidae) populations in Wisconsin identified by Sass et al., (2021), we tested for potential abiotic and biotic predictors of walleye recruitment depensation. The best fitting model contained covariates for climate, land cover, and fish community composition, all interacting with the relative abundance of largemouth bass (Micropterus salmoides, Centrarchidae). The consistent interaction effect of largemouth bass across the other covariates suggests a key role of this species in regulating walleye recruitment dynamics at low population size. The risk of depensation was negatively correlated with largemouth bass abundance in our dataset, pointing towards continued challenges for walleye populations given the increasingly favorable social and environmental conditions for largemouth bass. Using the model, vulnerability to depensation was predicted for an additional 115 walleye lakes with insufficient data to directly estimate the risk of depensation. Predictions suggested that 73 prediction lakes are vulnerable to depensatory recruitment should population sizes significantly decrease. This predictive framework could be used to prioritize lakes for different management actions based on depensation strength and average adult population size. Lakes with low walleye abundances, but low risk of depensation, may be more likely to respond positively to management efforts and are likely better candidates than those where depensation effects are likely strong when abundance is low.

From lab to field: biological control of the Japanese beetle with entomopathogenic fungi.

The Japanese beetle, Popillia japonica, is an invasive scarab and listed as quarantine organism in many countries worldwide. Native to Japan, it has invaded North America, the Azores, and recently mainland Europe. Adults are gregarious and cause agricultural and horticultural losses by feeding on leaves, fruits, and flowers of a wide range of crops and ornamental plants. Larvae feed belowground and damage grassland. To date, no efficient and environmentally friendly control measure is available. Larval populations of other scarab species such as Phyllopertha horticola and Melolontha melolontha are controlled by applying spores of the entomopathogenic fungi Metarhizium brunneum and Beauveria brongniartii to larval habitats. Here, we tested this control strategy against Japanese beetle larvae in grasslands, as well as spore spray applications against adults in crops. Using both, large-scale field experiments and inoculation experiments in the laboratory, we assess the efficacy of registered fungal strains against Japanese beetle larvae and adults. Metarhizium brunneum BIPESCO 5 established and persisted in the soil of larval habitats and on the leaves of adult's host plants after application. However, neither larval nor adult population sizes were reduced at the study sites. Laboratory experiments showed that larvae are not susceptible to M. brunneum ART 212, M. brunneum BIPESCO 5, and B. brongniartii BIPESCO 2. In contrast, adults were highly susceptible to all three strains. When blastospores were directly injected into the hemolymph, both adults and larvae showed elevated mortality rates, which suggests that the cuticle plays an important role in determining the difference in susceptibility of the two life stages. In conclusion, we do not see potential in adapting the state-of-the-art control strategy against native scarabs to Japanese beetle larvae. However, adults are susceptible to the tested entomopathogenic fungi in laboratory settings and BIPESCO 5 conidiospores survived for more than three weeks in the field despite UV-radiation and elevated temperatures. Hence, control of adults using fungi of the genera Beauveria or Metarhizium is more promising than larval control. Further research on efficient application methods and more virulent and locally adapted fungal strains will help to increase efficacy of fungal treatments for the control of P. japonica.

Use of electronic cigarettes and hookah in Brazil: a new and emerging landscape. The Covitel study, 2022.

To estimate the prevalence of current commercial cigarette smoking, as well as those of e-cigarette and hookah experimentation and current use among adults (≥ 18 years of age) in Brazil. This study was based on a countrywide cross-sectional telephone-based survey conducted in 2022. The sample was designed to be representative of the five macroregions in Brazil and included 1,800 individuals from each of the regions. Telephone numbers, using a random digit dialing procedure, were proportionally selected for each direct distance dialing code in each region and then electronically validated (i.e., 900 cell and 900 landline phone numbers per region). Information on current commercial cigarette smoking (regardless of frequency/amount), as well as lifetime history of or current e-cigarette and hookah use (regardless of amount), were collected. The prevalence of lifetime history of e-cigarette and hookah use was identical (7.3%; 95% CI: 6.0-8.9), whereas the prevalence of current commercial cigarette smoking was 12.2% (95% CI: 10.4-14.1). Young adults (18-24 years) had the highest prevalence of e-cigarette experimentation (19.7%; 95% CI: 15.1-17.0) and hookah experimentation (17%; 95% CI: 12.2-23.2). E-cigarette and hookah use was more common in the Central-West region and among those with a high level of education, whereas current commercial cigarette smoking was more common among those with a lower level of education. Individuals who used the three forms of nicotine delivery corresponded to 1.5% of the sample (nearly 2 million individuals based on the estimated size of the Brazilian adult population). Surveillance is essential for the monitoring and prevention of these new forms of nicotine consumption.

Close-kin mark-recapture methods to estimate demographic parameters of mosquitoes.

Close-kin mark-recapture (CKMR) methods have recently been used to infer demographic parameters such as census population size and survival for fish of interest to fisheries and conservation. These methods have advantages over traditional mark-recapture methods as the mark is genetic, removing the need for physical marking and recapturing that may interfere with parameter estimation. For mosquitoes, the spatial distribution of close-kin pairs has been used to estimate mean dispersal distance, of relevance to vector-borne disease transmission and novel biocontrol strategies. Here, we extend CKMR methods to the life history of mosquitoes and comparable insects. We derive kinship probabilities for mother-offspring, father-offspring, full-sibling and half-sibling pairs, where an individual in each pair may be a larva, pupa or adult. A pseudo-likelihood approach is used to combine the marginal probabilities of all kinship pairs. To test the effectiveness of this approach at estimating mosquito demographic parameters, we develop an individual-based model of mosquito life history incorporating egg, larva, pupa and adult life stages. The simulation labels each individual with a unique identification number, enabling close-kin relationships to be inferred for sampled individuals. Using the dengue vector Aedes aegypti as a case study, we find the CKMR approach provides unbiased estimates of adult census population size, adult and larval mortality rates, and larval life stage duration for logistically feasible sampling schemes. Considering a simulated population of 3,000 adult mosquitoes, estimation of adult parameters is accurate when ca. 40 adult females are sampled biweekly over a three month period. Estimation of larval parameters is accurate when adult sampling is supplemented with ca. 120 larvae sampled biweekly over the same period. The methods are also effective at detecting intervention-induced increases in adult mortality and decreases in population size. As the cost of genome sequencing declines, CKMR holds great promise for characterizing the demography of mosquitoes and comparable insects of epidemiological and agricultural significance.

Polyandry and non-random fertilisation maintain long-term genetic diversity in an isolated island population of adders (Vipera berus).

Conservation genetic theory suggests that small and isolated populations should be subject to reduced genetic diversity i.e., heterozygosity and allelic diversity. Our 34 years study of an isolated island population of adders (Vipera berus) in southern Sweden challenges this notion. Despite a lack of gene flow and a yearly mean estimated reproductive adult population size of only 65 adult adders (range 12-171), the population maintains high levels of heterozygosity and allelic diversity similar to that observed in two mainland populations. Even a 14-year major "bottleneck" i.e., a reduction in adult adder numbers, encompassing at least four adder generations, did not result in any reduction in the island adders' heterozygosity and allelic diversity. Female adders are polyandrous, and fertilisation is non-random, which our empirical data and modelling suggest are underpinning the maintenance of the population's high level of heterozygosity. Our empirical results and subsequent modelling suggest that the positive genetic effects of polyandry in combination with non-random fertilisation, often overlooked in conservation genetic analyses, deserve greater consideration when predicting long-term survival of small and isolated populations.