Adult Life Stages Research Articles

Effects of multiple stress events at different stages of life on the incidence of metabolic syndrome.

To investigate the effects of multiple stress events in different stages of life on the incidence of metabolic syndrome (MetS). Miners from Tangshan, China, were recruited for this study. Workers of the Kailuan Mining Group were evaluated to investigate whether exposure to Tangshan earthquakes during the fetal period in 1976. Adult life events and childhood trauma were assessed separately via the Life Event Scale and Childhood Trauma Questionnaire. The subjects were physically examined and general demographic data such as waist circumference were collected. Blood samples were collected for measurement of metabolic parameters. Corticotropin releasing hormone(CRH) levels was measured by enzyme-linked immunosorbent assay (ELISA). The subjects were divided into four groups according to their exposure to traumatic events in different stages of life: no exposure group, 1-exposure group, 2-exposures group, and 3-exposures group. The incidence of MetS, metabolic parameters and CRH levels in each of the four groups was compared. In all, 626 people were enrolled; of these, 183, 262, 150, and 31 were in the no exposure, 1-exposure, 2-exposures, and 3-exposure groups, respectively. A remarkable variation in the incidence of MetS was observed among the four groups (x2 = 16.462, P<0.001). MetS incidence increased with the increasing number of traumatic events, except for in the no exposure group (17.9% in 1-exposure group, 24.7% in 2-exposure group, and 48.4% in the 3-exposure group). Multivariate logistic regression analysis showed that exposure to multiple stress during the fetal, childhood, and adult stages of life represent independent risk factors for developing MetS (OR=3.134, 95%CI=1.042-9.429). Smoking increased the risk of developing MetS (OR=1.809, 95%CI=1.140-2.871). Exposure to multiple traumatic events in distinct life stages increases the risk of developing MetS. Smoking is a risk factor for developing MetS.

Variable habitat use supports fine-scale population differentiation of a freshwater piscivore (northern pike, Esox lucius) along salinity gradients in brackish lagoons.

In mobile animals, selection pressures resulting from spatio-temporally varying ecological factors often drive adaptations in migration behavior and associated physiological phenotypes. These adaptations may manifest in ecologically and genetically distinct ecotypes within populations. We studied a meta-population of northern pike (Esox lucius) in brackish environments and examined intrapopulation divergence along environmental gradients. Behavioral phenotypes in habitat use were characterized via otolith microchemistry in 120 individuals sampled from brackish lagoons and adjacent freshwater tributaries. We genotyped 1514 individual pike at 33highly informative genetic markers. The relationship between behavioral phenotype and genotype was examined in a subset of 101 pikes for which both phenotypic and genomic data were available. Thermosaline differences between juvenile and adult life stages indicated ontogenetic shifts from warm, low-saline early habitats towards colder, higher-saline adult habitats. Four behavioral phenotypes were found: Freshwater residents, anadromous, brackish residents, and cross-habitat individuals, the latter showing intermediary habitat use between brackish and freshwater areas. Underlying the behavioral phenotypes were four genotypes,putative freshwater, putativeanadromous, and two putativelybrackish genotypes. Through phenotype-genotype matching, three ecotypes were identified: (i) a brackish resident ecotype, (ii) a freshwater ecotype expressing freshwater residency or anadromy, and (iii) a previously undescribed intermediary cross-habitat ecotype adapted to intermediate salinities, showing limited reliance on freshwater. Life-time growth of all ecotypes was similar, suggesting comparable fitness. Bycombining genetic data with lifelong habitat use and growth as a fitness surrogate, our study revealed strong differentiation in response to abiotic environmental gradients, primarily salinity, indicating ecotype diversity in coastal northern pike is higher than previously believed.

A Life-Stage Approach to Precision Nutrition: A Narrative Review.

The concept of precision nutrition highlights the customization of nutrition to specific needs, emphasizing that a one-size-fits-all approach is not sufficient for either optimal nutrition or optimal health. Precision nutrition encompasses a range of factors, from broad strata of age and sex categories to personal characteristics such as lifestyle to an individual's unique genotype. This breadth of scope requires us to consider how precision nutrition can be implemented in an inclusive and appropriate way for individuals and groups within real-life populations. In this narrative review, we explore the potential of precision nutrition through a life-stage approach that emphasizes age- and gender-specific nutritional needs as these change across the lifespan. Focusing on adult life stages, we delineated trends in age-related conditions and health needs among Korean adults based on national-level survey data (KNHANES 2019-2021). We also reviewed the intake of nutrients associated with these health needs to better understand how life-stage guided approaches to nutrition and supplementation could support optimal health. Looking beyond preventing deficiency or disease, we discuss how tailored supplementation of essential vitamins, minerals, and certain bioactive substances could promote healthy functioning. Finally, we discuss the complexities and challenges of developing multivitamin/multimineral supplements (MVMS) to support life-stage appropriate nutrition while maximizing adherence. Future prospects include leveraging advancements in intelligent technologies and dietary assessments for tracking nutrient intake and health indicators and using these to optimize MVMS formulations in ways that are sensitive to a person's needs and priorities/preferences at different life stages. By adopting a life-stage guided approach to nutrition, we can better support health and well-being across the lifespan.

Cross-sectional and longitudinal evaluation of heart-to-brachium pulse wave velocity for cardiovascular disease risk.

Heart-brachium pulse wave velocity (hbPWV) is a promising measure of arterial stiffness including the proximal aorta. To characterize age-associated changes and the clinical utilities of hbPWV, we evaluated the impacts of age and cardiovascular disease (CVD) risks on hbPWV cross-sectionally (N = 7868) and longitudinally (N = 3710, followed by 9.1 ± 2.0 years). hbPWV were obtained using two validated equations for arterial path length (with and without considering age-related aortic elongations). Brachial-ankle pulse wave velocity (baPWV) was used as a comparative measure. Repeated-measures correlation (rmcorr) and regression analyses were used to characterize associations of PWVs with age and Framingham's general CVD risk score (FRS). In the cross-sectional study, hbPWVs derived by both equations showed stronger correlation with age (r = 0.746 ~ 0.796) and FRS (r = 0.714-0.749) than baPWV (r = 0.554 and r = 0.643). Furthermore, hbPWVs correlated with FRS even after controlling for age (r = 0.260 ~ 0.269, P < 0.0001). In the longitudinal study, hbPWVs demonstrated significantly higher rmcorr coefficient with age than baPWV (rrm=0.439-0.511 vs. 0.307, P < 0.0001). Across the adult lifespan, age-related increases in hbPWVs were almost consistent, starting from young adults, while baPWV displayed accelerated increases with age. A receiver operating characteristic curve analysis indicated that hbPWVs depicted more robust ability to stratify general CVD risk compared with baPWV (AUC = 0.896-0.913 vs. 0.833, P < 0.0001). The results of the follow-up study were consistent with the findings of the cross-sectional investigation. Our findings suggest that hbPWV undergoes a linear augmentation with age, commencing from an early adult life stage onward, rendering it a potential marker for discerning CVD risk.

A Look at External Political Efficacy and the Role of Digital Skills in the Adults U.S. Population

The ability to effectively use digital technology and problem-solve are critical skills for maintaining democratic health, particularly as civil society and the modern digital landscape continuously evolve. However, information on whether individuals have the critical problem-solving skills to use digital technology and confidently affect change is yet to be further explored. Using data from the 2017 Program for International Assessment of Adult Competencies ( n = 2749), we examined the associations between digital problem-solving skills and the three levels (low, neutral, high) of external political efficacy in the U.S. adult population. We used multinomial logistic regression and found a positive association between digital problem-solving skills and external political efficacy, while explanations for the three levels of efficacy are nuanced. Continuous development of digital problem-solving skills through adult education has implications for political efficacy, and ultimately for the promotion of a variety of civic engagement in the adult life stages.

Timing-dependent effects of elevated temperature on reproductive traits in the European corn borer moth.

Elevated temperature often has life stage-specific effects on ectotherms because thermal tolerance varies throughout ontogeny. Impacts of elevated temperature may extend beyond the exposed life stage, if developmental plasticity causes early exposure to carry over, or if exposure at multiple life stages cumulatively produces effects. Reproductive traits may be sensitive to different thermal environments experienced during development, but such effects have not been comprehensively measured in Lepidoptera. In this study, we investigate how elevated temperature at different life stages alters reproduction in the European corn borer moth, Ostrinia nubilalis. We tested effects of exposure to elevated temperature (28°C) separately or additively during larval, pupal, and adult life stages compared to control temperatures (23°C). We found that exposure to elevated pupal and adult temperature decreased the number of egg clusters produced, but exposure limited to a single stage did not significantly impact reproductive output. Furthermore, elevated temperature during the pupal stage led to a faster transition to the adult stage and elevated larval temperature altered synchrony of adult eclosion, either by itself or combined with pupal temperature exposure. These results suggest that exposure to elevated temperature during development alters reproduction in corn borers in multiple ways, including through carry-over and additive effects. Additive effects of temperature across life stages are thought to be less common than stage-specific or carry-over effects, but our results suggest thermal environments experienced at all life stages need to be considered when predicting reproductive responses of insects to heatwaves.

Evaluating foliar insecticides and economic thresholds for Tychius picirostris (Coleoptera: Curculionidae) management in Oregon white clover seed production.

The clover seed weevil, Tychius picirostris Fabricius (Coleoptera: Curculionidae), is a major pest in Oregon white clover seed crops. Reliance on synthetic pyrethroid insecticides and limited availability of diverse modes of action (MoAs) has increased insecticide resistance selection in regional T. picirostris populations, emphasizing the need to evaluate novel chemistries and rotational strategies for effective insecticide resistance management (IRM). The efficacy of 8 foliar insecticide formulations for managing T. picirostris adult and larval life stages was determined in small and large-plot field trials across 2 crop years. In both years, bifenthrin (Brigade 2EC), the grower's standard, showed negligible adult and larval suppression. Insecticide formulations with isocycloseram and cyantraniliprole active ingredients reduced adult and larval populations when applied at BBCH 59-60 (prebloom) and BBCH 65-66 (full bloom) growth stages, respectively. While differences in T. picirostris abundance were observed among insecticide treatments, seed yield differences were not detected in large-plot trials. Larval abundance was correlated with reduced seed yield, and an economic threshold of ≥3 larvae per 30 inflorescences was determined as a conservative larval threshold to justify foliar applications of diamide insecticides. Additional commercial white clover seed fields were surveyed to compare larval scouting techniques, including a standard Berlese funnel and a grower's do-it-yourself funnel. Both larval extraction techniques were correlated and provided similar estimates of larval abundance. These findings demonstrate new MoAs, optimal insecticide application timing, and larval monitoring methods that can be incorporated into an effective T. picirostris IRM program in white clover seed crops.

Biallelic variants in Plexin B2 (PLXNB2) cause amelogenesis imperfecta, hearing loss and intellectual disability

BackgroundPlexins are large transmembrane receptors for the semaphorin family of signalling proteins. Semaphorin-plexin signalling controls cellular interactions that are critical during development as well as in adult life stages. Nine...

Swimming Performance Assessments of Fish Species of Greatest Conservation Need to Inform Future Stream Crossing Designs in Texas

Conventional structures associated with stream crossings such as bridges and culverts can lead to zones of high-velocity water flow that impede fish passage. Such obstacles are likely to harm native fish populations by impacting migrations critical to their life history strategies, causing habitat fragmentation and extirpation, thereby limiting population growth and distribution. Due to the high rates of human population growth and development occurring in Texas, this is an issue of particular concern for fish designated as species of greatest conservation need (SGCN). This project focused on four SGCN fishes native to the Edwards Plateau Ecoregion, namely the Guadalupe Bass, Guadalupe Roundnose Minnow, Guadalupe Darter, and Plateau Shiner, at both adult (all species) and juvenile (Guadalupe Bass only) life stages. Our primary aim was to aid in the design of future culverts associated with stream crossings (or the modification of existing culverts) so that the water velocities through these structures do not exceed the swimming capacities of our target SGCN fishes. To this end, we assessed their maximum sustained swimming speeds (Ucrit) under a typical range of Edwards Plateau stream temperatures (15, 22.5, and 30 °C) to be used in site-specific calculations of the maximum allowable culvert water velocities (Vf). A secondary objective was to collect physiological endpoints of relevance to the overall swimming performance including the maximum burst swimming speeds (Umax), metabolic rate measurements (i.e., standard metabolic rate (SMR), maximum metabolic rate (MMR), and aerobic scope (AS)), cost of transport (COT), and optimal swimming speed (Uopt). Temperature-related effects were observed that can be used to inform site-specific culvert designs. In general, the highest Ucrit values for the tested species were near, or possibly between, 22.5 and 30 °C, while Umax stayed relatively consistent among treatments.

Thermal adaptation affects the temperature-dependent toxicity of the insecticide imidacloprid to soil invertebrates

Terrestrial ectotherms are vulnerable to climate change since their biological rates depend on the ambient temperature. As temperature may interact with toxicant exposure, climate change may cause unpredictable responses to toxic stress. A population's thermal adaptation will impact its response to temperature change, but also to interactive effects from temperature and toxicants, but these effects are still not fully understood. Here, we assessed the combined effects of exposure to the insecticide imidacloprid across the temperatures 10–25 °C of two populations of the Collembola Hypogastrura viatica (Tullberg, 1872), by determining their responses in multiple life history traits. The con-specific populations differ considerably in thermal adaptations; one (arctic) is a temperature generalist, while the other (temperate) is a warm-adapted specialist. For both populations, the sub-lethal concentrations of imidacloprid became lethal with increasing temperature. Although the thermal maximum is higher for the warm-adapted population, the reduction in survival was stronger. Growth was reduced by imidacloprid in a temperature-dependent manner, but only at the adult life stage. The decrease in adult body size combined with the absence of an effect on the age at first reproduction suggests a selection on the timing of maturation. Egg production was reduced by imidacloprid in both populations, but the negative effect was only dependent on temperature in the warm-adapted population, with no effect at 10 °C, and decreases of 41 % at 15 °C, and 74 % at 20 °C. For several key traits, the population best adapted to utilize high temperatures was also the most sensitive to toxic stress at higher temperatures. It could be that by allocating more energy to faster growth, development, and reproduction at higher temperatures, the population had less energy for maintenance, making it more sensitive to toxic stress. Our findings demonstrate the need to take into account a population's thermal adaptation when assessing the interactive effects between temperature and other stressors.

Among-population variation in drought responses is consistent across life stages but not between native and non-native ranges.

Understanding how widespread species adapt to variation in abiotic conditions across their ranges is fundamental to ecology. Insight may come from studying how among-population variation (APV) in the common garden corresponds with the environmental conditions of source populations. However, there are no such studies comparing native vs non-native populations across multiple life stages. We examined APV in the performance and functional traits of 59 Conyza canadensis populations, in response to drought, across large aridity gradients in the native (North America) and non-native (Eurasia) ranges in three experiments. Our treatment (dry vs wet) was applied at the recruitment, juvenile, and adult life stages. We found contrasting patterns of APV in drought responses between the two ranges. In the native range, plant performance was less reduced by drought in populations from xeric than mesic habitats, but such relationship was not apparent for non-native populations. These range-specific patterns were consistent across the life stages. The weak adaptive responses of non-native populations indicate that they can become highly abundant even without complete local adaptation to abiotic environments and suggest that long-established invaders may still be evolving to the abiotic environment. These findings may explain lag times in invasions and raise concern about future expansions.

Growth and longevity of the endangered freshwater pearl mussel (Margaritifera margaritifera): Implications for conservation and management

AbstractKey life‐history data, such as growth and age, are necessary to effectively manage and conserve threatened freshwater mussel species. Traditionally growth and age studies require large yet destructive sample sizes covering all age classes. Such methods pose a risk to populations of conservation concern, and therefore, alternative methods that need only limited sample sizes are necessitated to prevent further threats to such populations. We applied retrospective shell growth at age reconstructions to 98 critically endangered freshwater pearl mussel (FPM) individuals from 34 populations across Finland and Sweden, enabling the use of extremely small sample sizes (n = 1–6 per population). We compared the performance of six different growth models with the reconstructed size‐at‐age data across FPM juvenile (&lt;20 years old) and adult life stages. The growth reconstruction model showed reasonable skill in reconstructing FPM growth patterns. The von Bertalanffy model showed to be a good general descriptor of growth for FPM, but it systematically underestimated the asymptotic size. The power law model was the most accurate in estimating juvenile growth (lowest deviances from the size‐at‐age data). FPM showed great variability in longevity (Amax = 54–254 years) and growth constant k (0.018–0.057 year−1). Our results show that reasonable estimates of growth can be attained even when sample sizes are extremely limited. The results can be further applied to gain knowledge on the population's age structure, size at maturation, and recovery potential. The methodology is applicable to other freshwater mussel species of conservation concern.

Evaluating the impact of captive ancestry on the growth and survival of Delta Smelt in a captive environment

Delta Smelt Hypomesus transpacificus, is an endangered fish endemic to the California San Francisco Bay-Delta, USA. Extreme declines of the wild Delta Smelt population have prompted use of cultured fish to supplement the wild population since 2021 to prevent the extinction of the species. However, evidence of adaptation to captivity in the conservation hatchery has raised concerns about the use of captive-bred fish for supplementation and how these fish may differ from wild Delta Smelt. We conducted a study over two consecutive years to investigate the effects of varying levels of captive ancestry on the growth and survival of cultured Delta Smelt from two different domestication index (DI) groups, capturing high DI and low DI values. Fish growth and survival were monitored in the hatchery from larval to adult life-stages to determine differences between DI groups. Our findings indicate that DI can have a significant influence as we observed reduced growth and survival of low DI fish at multiple life-stages. The results suggest that the DI of released hatchery-reared Delta Smelt may affect the performance of their offspring in the natural environment. Further studies might be necessary to develop a better management strategy on the released fish to enhance the conservation efforts.

Neoblast-like stem cells of Fasciola hepatica.

The common liver fluke (Fasciola hepatica) causes the disease fasciolosis, which results in considerable losses within the global agri-food industry. There is a shortfall in the drugs that are effective against both the adult and juvenile life stages within the mammalian host, such that new drug targets are needed. Over the last decade the stem cells of parasitic flatworms have emerged as reservoirs of putative novel targets due to their role in development and homeostasis, including at host-parasite interfaces. Here, we investigate and characterise the proliferating cells that underpin development in F. hepatica. We provide evidence that these cells are capable of self-renewal, differentiation, and are sensitive to ionising radiation-all attributes of neoblasts in other flatworms. Changes in cell proliferation were also noted during the early stages of in vitro juvenile growth/development (around four to seven days post excystment), which coincided with a marked reduction in the nuclear area of proliferating cells. Furthermore, we generated transcriptomes from worms following irradiation-based ablation of neoblasts, identifying 124 significantly downregulated transcripts, including known stem cell markers such as fgfrA and plk1. Sixty-eight of these had homologues associated with neoblast-like cells in Schistosoma mansoni. Finally, RNA interference mediated knockdown of histone h2b (a marker of proliferating cells), ablated neoblast-like cells and impaired worm development in vitro. In summary, this work demonstrates that the proliferating cells of F. hepatica are equivalent to neoblasts of other flatworm species and demonstrate that they may serve as attractive targets for novel anthelmintics.

Intraspecific variation in thermal performance curves for early development in Fundulus heteroclitus.

Thermal performance curves (TPCs) provide a framework for understanding the effects of temperature on ectotherm performance and fitness. TPCs are often used to test hypotheses regarding local adaptation to temperature or to develop predictions for how organisms will respond to climate warming. However, for aquatic organisms such as fishes, most TPCs have been estimated for adult life stages, and little is known about the shape of TPCs or the potential for thermal adaptation at sensitive embryonic life stages. To examine how latitudinal gradients shape TPCs at early life stages in fishes, we used two populations of Fundulus heteroclitus that have been shown to exhibit latitudinal variation along the thermal cline as adults. We exposed embryos from both northern and southern populations and their reciprocal crosses to eight different temperatures (15°C, 18°C, 21°C, 24°C, 27°C, 30°C, 33°C, and 36°C) until hatch and examined the effects of developmental temperature on embryonic and larval traits (shape of TPCs, heart rate, and body size). We found that the pure southern embryos had a right-shifted TPC (higher thermal optimum (Topt) for developmental rate, survival, and embryonic growth rate) whereas pure northern embryos had a vertically shifted TPC (higher maximum performance (Pmax) for developmental rate). Differences across larval traits and cross-type were also found, such that northern crosses hatched faster and hatched at a smaller size compared to the pure southern population. Overall, these observed differences in embryonic and larval traits are consistent with patterns of both local adaptation and countergradient variation.

Using Bayesian multispecies models to evaluate fish and invertebrate detection probability and distribution in the hypersaline Bahia Grande tidal basin

AbstractObjectiveIn 2000, the Laguna Atascosa National Wildlife Refuge acquired the Bahia Grande (Texas) management unit, a space that had lain barren and arid for 70 years. A large cooperative partnership launched a restoration project to replenish the basin and recover its original tidal hydrology. In 2005, the construction of a pilot channel successfully restored water throughout the basin, and plans to eventually widen the channel were developed. Our study aims to evaluate an estuarine habitat restoration by assessing ecological drivers and the impacts on species diversity.MethodsWe evaluated species richness, detection/occupancy rates, and species–habitat relationships, and we estimated the sampling effort required to achieve a given level of relative precision if relative abundance was used instead of occupancy to inform future sampling. Sampling gear included bag seines for juvenile life stages and gill nets for capturing subadult and adult life stages. For analysis, we used a Bayesian negative binomial linear mixed‐effects model to evaluate richness–habitat relationships and a hierarchical Bayesian multispecies model to evaluate individual species–habitat relationships, and we calculated the total number of fish captured and relative standard error by gear and sample year to produce a precise estimate of relative abundance.ResultOverall, 29 species were caught between 2018 and 2021. Salinity emerged as a clear driver in the Bahia Grande, as both species richness and individual‐level responses were negatively associated with high salinity values. We found that catch estimated as relative abundance had much variability, as is typical of most survey programs assuming constant detectability, and the number of net sets or seine hauls required to achieve a given level of relative precision varied considerably depending on the species, season, year, and gear type. The most collected species were found in the upper extremes of their salinity tolerances—potentially a unique adaptation to this hypersaline system.ConclusionBaseline data suggest that for the channel widening to be successful, there must be a noticeable increase in suitable habitat characteristics throughout the basin.

Thermal stressors during embryo incubation have limited ontogenic carryover effects in brook trout

Winter climate is changing rapidly in northern latitudes, and these temperature events have effects on salmonid thermal biology. Stressors during winter egg incubation could reduce hatching success and physiological performance of fall-spawning fishes. Here we quantified the potential for ontogenic carryover effects from embryonic thermal stress in multiple wild and hatchery-origin populations of brook trout (Salvelinus fontinalis), a temperate ectotherm native to northeastern North America. Fertilized eggs from four populations were incubated over the winter in the laboratory in four differing thermal regimes: ambient stream-fed water, chronic warming (+2 °C), ambient with a mid-winter cold-shock, and short-term warming late during embryogenesis (to stimulate an early spring). We examined body size and upper thermal tolerance at the embryonic, fry (10 weeks post-hatch and 27–30 weeks post-hatch) and gravid adult (age 2+) life stages (overall N = 1482). In a separate experiment, we exposed developing embryos to acute seven-day heat stress events immediately following fertilization and at the eyed-egg stage, and then assessed upper thermal tolerance (CTmax) 37 weeks post-hatch. In all cases, fish were raised in common garden conditions after hatch (i.e., same temperatures). Our thermal treatments during incubation had effects that varied by life stage, with incubation temperature and life stage both affecting body size and thermal tolerance. Embryos incubated in warmer treatment groups had higher thermal tolerance; there was no effect of the mid-winter melt event on embryo CTmax. Ten weeks after hatch, fry from the ambient and cold-shock treatment groups had higher and less variable thermal tolerance than did the warmer treatment groups. At 27–30 post-hatch and beyond, differences in thermal tolerance among treatment groups were negligible. Collectively, our study suggests that brook trout only exhibit short-term carryover effects from thermal stressors during embryo incubation, with no lasting effects on phenotype beyond the first few months after hatch.

Can alpine species take the heat? Impacts of increased temperatures on early life stages

Abstract Alpine plant species are particularly vulnerable to climate change. Temperature fluctuations are projected to be most severe at high elevations. Even small shifts in temperature have major consequences on phenology, reproduction, and community composition. Early life stages are arguably the most important processes in the fitness of an individual plant and the dynamics and persistence of plant populations. These initial developmental stages are expected to be more vulnerable to changes in climate than adult life stages. To understand how early life stages of alpine plant species will respond to warming temperatures, seeds and seedlings of two species were exposed to three different temperature regimes. Temperatures were based on current and projected conditions under low and high emission scenarios. Two rare alpine species performed better under warmer temperatures at both the germination and seedling stages. The results show that early life stages of alpine plants may not be at high risk from warming temperatures; however, there are many other shifting climatic factors to consider, resulting from climate change beyond temperature alone.

Reproductive output and other adult life-history traits of black soldier flies grown on different organic waste and by-products

The interest in mass-rearing black soldier fly (Hermetia illucens) larvae for food and feed is rapidly increasing. This is partly sparked by the ability of the larvae to efficiently valorise a wide range of organic waste and by-products. Primarily, research has focused on the larval stage, hence underprioritizing aspects of the adult biology, and knowledge on reproduction-related traits such as egg production is needed. We investigated the impact of different organic waste and by-products as larval diets on various life-history traits of adult black soldier flies in a large-scale experimental setup. We reared larvae on four different diets: spent Brewer’s grain, ground carrots, Gainesville diet, and ground oranges. Traits assessed were development time to pupa and adult life-stages, adult body mass, female lifespan, egg production, and egg hatch. Larval diet significantly impacted development time to pupa and adult, lifespan, body size, and egg production. In general, flies reared on Brewer’s grain developed up to 4.7 d faster, lived up to 2.3 d longer, and produced up to 57% more eggs compared to flies reared on oranges on which they performed worst for these traits. There was no effect of diet type on egg hatch, suggesting that low-nutritious diets, i.e. carrots and oranges, do not reduce the quality but merely the quantity of eggs. Our results demonstrate the importance of larval diet on reproductive output and other adult traits, all important for an efficient valorisation of organic waste and by-products, which is important for a sustainable insect-based food and feed production.

Early larval exposure to flumethrin induces long-term impacts on survival and memory behaviors of adult worker bees Apis mellifera

Flumethrin has been supplied as an acaricide for Varroa mite control in world-wide apiculture due to its low lethal effects on honey bees. However, little is known about the effects of short-term flumethrin exposure in the larval stage on adult life stage of bees involving survival status, foraging and memory-related behaviors. Here, we found that exposure to flumethrin at 1 mg/L during larval stage reduced survival and altered foraging activities including induced precocious foraging activity, decreased foraging trips and time, and altered rotating day-off status of adult worker bees using the radio frequency identification system. Furthermore, larval exposure at 1 mg/L flumethrin influenced the correct proboscis extension responses of 7-day-old worker bees and decreased homing rates of 20-day-old worker bees, suggesting that 1 mg/L flumethrin exposure at larval stage could affect memory-related behaviors of adult bees; meanwhile, three genes related to memory (GluRA, Nmdar1 and Tyr1) were certainly down-regulated varying different flumethrin concentrations (0.01, 0.1, and 1 mg/L). Combined with transcriptomic sequencing, differentially expressed genes involved in olfactory memory of adult bees were completely down-regulated under flumethrin exposure. Our findings highlight the unprecedented impact of short-term exposure of insecticides on honey bees in long-term health monitoring under field conditions.