Development Time Research Articles

Identifying the proximal cue(s) for pupal color variation in the bordered patch butterfly, Chlosyne lacinia (Lepidoptera: Nymphalidae)

Abstract Coloration is a multifaceted trait that serves various functions, including predator defense, thermoregulation, and immune response, among others. We investigated pupal color variation in Chlosyne lacinia pupae, focusing on identifying the cue that influences variation in melanization. Through laboratory experiments, we demonstrated that pupae reared on black backgrounds exhibited significantly higher melanization compared to those on white backgrounds. Additionally, black pupae experienced longer developmental periods, suggesting a trade-off between defense and developmental time. Our findings support crypsis as a likely evolutionary driver for increased melanization in response to substrate color. We discuss potential implications for predator avoidance, immune response, and developmental costs associated with melanization. This study provides insights into the adaptive significance of pupal melanization in response to environmental cues, shedding light on the complex interplay between life history traits in butterflies.

Unbinding the bindweed psyllid (Bactericera maculipennis [Hemiptera: Triozidae]) from its Convolvulus host exposes it to a novel bacterial symbiont

Abstract Psyllids (Hemiptera: Psylloidea) are herbivores that feed and reproduce on narrow subsets of hosts within a few related genera. During surveys of Solanum umbelliferum (Eschsch) (Solanaceae), we collected multiple life stages of Bactericera maculipennis (Crawford), a species exclusively associated with bindweeds (Convolvulaceae). We hypothesized that B. maculipennis has expanded its host range to include this solanaceous host. To test this, we quantified egg to adult development time on S. umbelliferum, 2 other solanaceous hosts, and Convolvulus arvensis L., the most suitable host for B. maculipennis in North America. B. maculipennis failed to develop on additional solanaceous hosts but developed significantly faster on S. umbelliferum than on C. arvensis. We also sampled for B. maculipennis at 27 S. umbelliferum populations and collected 24 individuals directly from S. umbelliferum plants. We confirmed all individuals are B. maculipennis and found that 10/24 were infected with the plant pathogen ‘Candidatus Liberibacter solanacearum’ (CLso), which is transmitted by the potato psyllid, B. cockerelli (Šulc). Half of infected individuals harbored CLso haplotype B, which is dominant in crops, but rare in S. umbelliferum. The other 50% harbored CLso haplotype Sumb2, previously documented in S. umbelliferum, but never in crops. Our results suggest that the host range of B. maculipennis has expanded to include a key wild host plant of B. cockerelli. This may create opportunities for exchange of multiple haplotypes of CLso between these 2 species, possibly facilitating the emergence of CLso variants as pathogens of plants in the Convolvulaceae.

The Relationship Between Astronomical and Developmental Times Emerging in Modeling the Evolution of Agents

The simplest evolutionary model for catching prey by an agent (predator) is considered. The simulation is performed on the basis of a software-emulated Intel i8080 processor. Maximizing the number of catches is chosen as the objective function. This function is associated with energy dissipation and developmental time. It is shown that during Darwinian evolution, agents with an initially a random set of processor commands subsequently acquire a successful catching skill. It is found that in the process of evolution, a logarithmic relationship between astronomical and developmental times arises in agents. This result is important for the ideas available in the literature about the close connection of such concepts as time, Darwinian selection, and the maximization of entropy production.

Effects and phenotypic consequences of transient thyrotoxicosis and hypothyroidism at different stages of zebrafish Danio rerio (Teleostei; Cyprinidae) skeleton development.

The effects and consequences of changes in thyroid hormones (THs) level are among the actively studied topics in teleost developmental and evolutionary biology. In most of the experimental models used, the altered hormonal status (either hypo- or hyperthyroidism) is a stable characteristic of the developing organism, and the observed phenotypic outcomes are the cumulative consequences of multiple TH-induced developmental changes. Meanwhile, the influence of the transient fluctuations of TH content on skeleton development has been much less studied. Here, we present experimental data on the developmental effects and phenotypic consequences of transient, pharmacologically induced thyrotoxicosis and hypothyroidism at different stages of ossified skeleton patterning in zebrafish. According to the results, the skeleton structures differed in TH sensitivity. Some showed a notable shift in the developmental timing and rate, while other demonstrated little or no response to changes in TH content. The developmental stages also differed in TH sensitivity. We identified a relatively short developmental period, during which changes in TH level significantly increased the developmental instability and plasticity, leading to phenotypic consequences comparable to those in fish with a persistent hypo- or hyperthyroidism. These findings allow this period to be considered as a critical developmental window.

Peripheral CaV2.2 channels in skin regulate prolonged heat hypersensitivity during neuroinflammation.

Neuroinflammation can lead to chronic maladaptive pain affecting millions of people worldwide. Neurotransmitters, cytokines, and ion channels are implicated in neuro-immune cell signaling but their roles in specific behavioral responses are not fully elucidated. Voltage-gated CaV2.2 channel activity in skin controls rapid and transient heat hypersensitivity induced by intradermal (id) capsaicin via IL-1α cytokine signaling. CaV2.2 channels are not, however, involved in mechanical hypersensitivity that developed in the id capsaicin animal model. Here, we show that CaV2.2 channels are also critical for heat hypersensitivity induced by id Complete Freund's Adjuvant (CFA). Id CFA, a model of chronic neuroinflammation, involves ongoing cytokine signaling for days leading to pronounced edema and hypersensitivity to sensory stimuli. Peripheral CaV2.2 channel activity in skin was required for the full development and week-long time course of heat hypersensitivity induced by id CFA but, paw edema and mechanical hypersensitivity were independent of CaV2.2 channel activity. CFA induced increases in several cytokines in hind paw fluid including IL-6 which was also dependent on CaV2.2 channel activity. Using IL-6 specific neutralizing antibodies in vivo we show that IL-6 contributes to heat hypersensitivity and, neutralizing both IL-1α and IL-6 was even more effective at reducing the magnitude and duration of CFA-induced heat hypersensitivity. Our findings demonstrate a functional link between CaV2.2 channel activity and the release of IL-6 in skin and show that CaV2.2 channels have a privileged role in the induction and maintenance of heat hypersensitivity during chronic forms of neuroinflammation in skin.Significance statement Neuroinflammation can lead to chronic maladaptive pain. Neurotransmitters, ion channels, cytokines, and cytokine receptors are implicated in neuron-immune signaling, but their importance in mediating specific behavioral responses are not fully elucidated. We show that the activity of peripheral CaV2.2 calcium ion channels in skin play a unique role in the induction and maintenance of heat hypersensitivity in the CFA model of prolonged neuroinflammation, but they are not involved in the development of edema and mechanical hypersensitivity. Blocking peripheral CaV2.2 channel activity reduces local cytokine levels in hind paws injected with CFA including IL-6, and neutralizing IL-6 reduces CFA-induced heat hypersensitivity. Our studies define key signaling molecules that act locally in skin to trigger and maintain heat hypersensitivity during chronic neuroinflammation.

Effects of continuous and transgenerational rearing in peanut leaves on the performance and enzyme activity of Spodoptera frugiperda (Lepidoptera: Noctuidae).

The invasive fall armyworm (FAW), Spodoptera frugiperda, is a polyphagous pest that significantly threatens crops worldwide. FAW may undergo adaptation, enhancing its ability to infect specific plant hosts. However, there is limited knowledge on this topic. After 8 generations of constant rearing on peanut leaves, the performance and enzyme activities of FAW were investigated in this study. Compared to FAW fed on the peanut cultivars 'Fuhua 8' and 'Quanhonghua 1' for 2 generations, those grown on leaves for 5 to 8 generations had significantly shorter pre-adult development times and total preoviposition periods. Fecundity also increased significantly, resulting in an overall improvement in population fitness as measured by demographic parameters. However, the F2 generation of FAW fed on corn leaves outperformed the F8 generation of FAW fed on peanut leaves. In the F2 generation, the FAW peanut population exhibited 30-55% supernumerary larval molts, which decreased substantially in the F5 and F8 generations. Notably, supernumerary larval molts displayed pupation and emergence rates comparable to normal larvae, regardless of the peanut cultivar or rearing generation. The activities of lipase and acetylcholinesterase increased significantly from the F2 to F8 generations, showing substantial negative and positive correlations with larval development time and fecundity, respectively. In conclusion, FAW demonstrated inferior performance on peanut leaves compared to corn leaves, despite its performance was significantly improved after 5 to 8 generations of acclimation. These results suggest that corn will continue to be the primary target crop for FAW in China.

Placental–Heart Axis: An Evolutionary Perspective

To maintain its development, the growing fetus is directly dependent on the placenta, an organ that acts as both a modulator and mediator. As an essential component of pregnancy that is derived from both maternal and fetal tissues, the placenta facilitates the passage of all oxygen and nutrients from the expecting parent to their fetuses. Further, the placenta conveys multiple impacts of the maternal environment to the growing fetus. The timing of placental development parallels that of the fetal cardiovascular system, and placental anomalies are implicated as a potential cause of congenital heart disease. For example, congenital heart disease is more common in pregnancies complicated by maternal preeclampsia, a condition characterized by placental dysfunction. Given the placenta’s intermediary links to the maternal environment and fetal health outcomes, it is an emerging focus of evolutionary medicine, which seeks to understand how interactions between humans and the environment affect our biology and give rise to disease. The present review provides an overview of the evolutionary and developmental courses of the placenta as well as their implications on infant health.

A vector system encoding histone H3 mutants facilitates manipulations of the neuronal epigenome

The differentiation of developmental cell lineages is associated with genome-wide modifications in histone H3 methylation. However, the causal role of histone H3 methylation in transcriptional regulation and cell differentiation has been difficult to test in mammals. The experimental overexpression of histone H3 mutants carrying lysine-to-methionine (K-to-M) substitutions has emerged as an alternative tool for inhibiting the endogenous levels of histone H3 methylation at specific lysine residues. Here, we leverage the use of histone K-to-M mutants by creating Enhanced Episomal Vectors that enable the simultaneous depletion of multiple levels of histone H3 lysine 4 (H3K4) or lysine 9 (H3K9) methylation in projection neurons of the mouse cerebral cortex. Our approach also facilitates the simultaneous depletion of H3K9 and H3K27 trimethylation (H3K9me3 and H3K27me3, respectively) in cortical neurons. In addition, we report a tamoxifen-inducible Cre-FLEX system that allows the activation of mutant histones at specific developmental time points or in the adult cortex, leading to the depletion of specific histone marks. The tools presented here can be implemented in other experimental systems, such as human in vitro models, to test the combinatorial role of histone methylations in developmental fate decisions and the maintenance of cell identity.

Life history in Caenorhabditis elegans: from molecular genetics to evolutionary ecology.

Life history is defined by traits that reflect key components of fitness, especially those relating to reproduction and survival. Research in life history seeks to unravel the relationships among these traits and understand how life history strategies evolve to maximize fitness. As such, life history research integrates the study of the genetic and developmental mechanisms underlying trait determination with the evolutionary and ecological context of Darwinian fitness. As a leading model organism for molecular and developmental genetics, Caenorhabditis elegans is unmatched in the characterization of life history-related processes, including developmental timing and plasticity, reproductive behaviors, sex determination, stress tolerance, and aging. Building on recent studies of natural populations and ecology, the combination of C. elegans' historical research strengths with new insights into trait variation now positions it as a uniquely valuable model for life history research. In this review, we summarize the contributions of C. elegans and related species to life history and its evolution. We begin by reviewing the key characteristics of C. elegans life history, with an emphasis on its distinctive reproductive strategies and notable life cycle plasticity. Next, we explore intraspecific variation in life history traits and its underlying genetic architecture. Finally, we provide an overview of how C. elegans has guided research on major life history transitions both within the genus Caenorhabditis and across the broader phylum Nematoda. While C. elegans is relatively new to life history research, significant progress has been made by leveraging its distinctive biological traits, establishing it as a highly cross-disciplinary system for life history studies.

Differential spatio-temporal responses of Red Sea coral reef benthic communities to a mass bleaching event

Understanding how coral reefs respond to disturbances is fundamental to assessing their resistance and resilience, particularly in the context of climate change. Due to the escalating frequency and intensity of coral bleaching events, it is essential to evaluate spatio-temporal responses of coral reef communities to disentangle the mechanisms underlying ecological changes. Here, we used benthic data collected from 59 reefs in the Red Sea over five years (2014–2019), a period that encompasses the 2015/2016 mass bleaching event. Reefs were located within three different geographic regions with different environmental settings: north (Duba; Al Wajh), central (Jeddah; Thuwal), and south (Al Lith; Farasan Banks; Farasan Islands). Coral community responses were region-specific, with communities in the south being more promptly affected than those in the northern and central regions, with hard and soft coral cover dropping drastically in several reefs from around > 40% to < 5% two years after bleaching. Coral bleaching effects were particularly evident in the decrease of cover in branching corals. Overall, we documented a shift towards a dominance of macroalgae, turf algae, and crustose coralline algae (CCA). Using remote sensing data, we analyzed sea surface temperature (SST) regimes at the study sites to infer potential drivers of changes in benthic composition. Both SST and Degree Heating Weeks (DHW) only partially aligned with the responses of benthic communities, highlighting the need for more accurate predictors of coral bleaching in the Red Sea. In times of intense coastal development along Saudi Arabia’s Red Sea coast, our study provides crucial baseline information on developments in coral reef community composition, as well as to guide decision-making, namely restoration efforts.

Clinical Benefit, Price, and Regulatory Approval of Cancer Drugs Granted Breakthrough Therapy Designation in China, 2020-2024

The China National Drug Administration (NMPA) established the breakthrough therapy designation (BTD) in 2020 to encourage the accelerated development of drugs for the prevention and treatment of diseases that are life-threatening. However, the differences between BTD and non-BTD cancer drugs regarding clinical benefit, regulatory approval, and price are unclear. To compare BTD and non-BTD cancer drugs in clinical benefit (defined as efficacy and safety), novelty, time to approval, and average monthly treatment price. This cross-sectional study analyzes the original indication of BTD and non-BTD novel cancer drugs approved by the NMPA between July 8, 2020, and July 8, 2024. Data on efficacy, safety, regulatory approval, and price of cancer drugs were extracted from pivotal clinical trials based on review reports published by the NMPA, peer-reviewed articles or meeting reports, and winning bid prices for cancer drugs in the Chinese provincial-level centralized procurement process. The main outcome was the efficacy and safety associated with BTD vs non-BTD cancer drugs, including progression-free survival (PFS), response rate (RR), duration of response, serious adverse events, grade 3 or higher adverse events, and treatment-related deaths. In addition, the time to approval, novelty, and initial and latest average monthly treatment prices were evaluated, as well as the average annual reduction rate (AARR; the sum of the reduction rates divided by the number of years for the monthly treatment price) for these cancer drugs. Between July 2020 and July 2024, 18 BTD (36%) and 32 non-BTD (64%) cancer drugs were approved by the NMPA. The median (IQR) clinical development time for BTD drugs was significantly shorter than for non-BTD drugs (5.6 [95% CI, 4.3-7.3] vs 6.6 [95% CI, 6.0-8.5] years; P = .02). No significant differences were observed in PFS (HR, 0.44 [95% CI, 0.38-0.52] vs HR, 0.51 [95% CI, 0.40-0.65]; P = .20), PFS gained (median [IQR], 5.4 [3.9-7.0] vs 2.7 [2.6-5.9] months; P = .77), RR (58% [95% CI, 45%-74%] vs 59% [95% CI, 51%-69%]; P = .85), and duration of response (median [IQR], 18.0 [15.0-21.6] vs 11.1 [7.4-17.4] months; P = .09) between BTD and non-BTD drugs. The rates of serious adverse events (37% [95% CI, 26%-52%] vs 32% [95% CI, 27%-36%]; P = .45), adverse events grade 3 or higher (64% [95% CI, 53%-77%] vs 55% [95% CI, 45%-68%]; P = .31), and treatment-related deaths (2% [95% CI, 1%-4%] vs 1% [95% CI, 1%-2%]; P = .10) were similar between BTD and non-BTD drugs. BTD drugs are more likely to be first-in-class drugs (5 of 18 [28%] vs 1 of 32 [3%]; P = .02). Differences in the median (IQR) initial ($5665 [$3542-$9321] vs $3361 [$2604-$5474]; P = .06) and latest ($5665 [$1553-$9321] vs $2145 [$1318-$4276]; P = .18) average monthly treatment prices for BTD drugs and non-BTD drugs were not significant. The median (IQR) AARRs for BTD drugs and non-BTD drugs were 15.2% (0%-46.9%) and 19.8% (1.0%-42.9%), respectively. The findings of this cross-sectional study suggest that BTD has facilitated faster time to market for cancer drugs and improved novelty, but the price of treatment is relatively higher. There was no significant difference on comparative efficacy and safety.

Problems And Solutions of Real Estate Industry in China

Since real estate industry is one of the national pillar industries in China, therefore, it has great contributions to China’s economy and society. for example, promoting the Chinese economic growth in the long-run, and it provide financial support to government and benefits for cities development. Secondly, real estate also helping the development of relevant business, creating large amount of job opportunities to society, for residents, they can enjoy higher living standard. However, at same time of rapid development of real estate industry and economic boost, they exist series of problems that harmful to society like real estate bubble, unfinished buildings and cooperates financing difficulties. aiming at these problems, this paper suggest that government can through promulgate some new policies, laws, and establish the compete financing channel mechanism to solve these kinds of problems. The target of this study is to help real estate industry in China keep healthy development.

A Neglected Fracture: Treatment and Infection of Seymour Fractures of the Hallux in the Pediatric Population.

Seymour physeal fractures of the distal phalanx of the Hallux in children are common but rarely described in the literature. There is limited literature investigating how these fractures should be specifically treated. Generally, good results are reported when open fractures are treated with debridement and antibiotics. This large retrospective review evaluates incidence of infection and compares outcomes of various treatments for Seymour physeal fractures of the distal phalanx of the Hallux in children. This study included patients ≤18 years of age treated for Seymour fractures of the Hallux between January 1, 2007, and November 20, 2018, at a single tertiary-care urban children's hospital. Demographic, injury, and treatment data were obtained via a retrospective review of electronic medical records, including closed versus open fracture status, time to treatment, and whether antibiotics were prescribed and taken. Initial radiographic imaging was examined by a single attending surgeon for angulation (degrees) and widening (mm). Outcome variables included the development of infection and the rate and success of healing. One hundred thirty-eight patients were included in our analysis. Most (84/138, 61%) fractures were closed and treated successfully without antibiotics. Treatment for open fractures varied greatly, with many of these fractures undergoing an incision and drainage procedure (I&D) (33/54, 61%) and antibiotic prescription (43/54, 76%). Most (47/54, 87%) open fractures did not develop infection. However, 7/54 open fractures presented with an active infection. Four out of seven (29%) of these fractures did not receive any treatment before infection presentation. Two others who presented with infection both had delayed antibiotics and neither underwent I&D. Fractures that either presented with or developed an infection presented significantly later than those fractures that did not develop infection (P<0.001). Neither angulation nor displacement correlated to the time of healing or development of infection. In our large cohort, the majority of open Seymour fractures of the Hallux treated in a timely manner did not develop infection, regardless of treatment. However, open fractures that presented multiple days after injury had an increased incidence of infection. Thus, for open fractures, we recommend timely antibiotics and I&D. Closed fractures may be treated conservatively, with no indication for reduction or use of antibiotics.

Pedagogic mediation for praxis development: supporting leaders and mentors in the English ECEC context

ABSTRACT Pedagogic mediation from Pedagogy-in-Participation in Portugal, as a context-specific approach to professional development, provides a participatory framework through which practice enhancements are supported. This research introduced ten ECEC leaders and mentors, within a specific local authority in England, to the democratic nature of pedagogic mediation and provided a community of practice within which this could be explored. Leaders and mentors documented their own reflections over several months and noted how they applied the elements of openness, listening, suspending and encountering to their professional role, supporting outcomes for children birth to four years of age. Reflective narratives were shared and a focus group supported the evaluation of pedagogic mediation within this English context. All ten leaders and mentors found pedagogic mediation helpful within their professional role. Specifically, the element of suspending was found to be most useful as it provided leaders and mentors licence to enable additional time for development and this in turn supported a more participatory approach. Whilst small-scale and context-specific, this research illustrates the benefits of contextual professional development undertaken at a flexible pace.

Improving reuse during the development process for web systems

Software reuse has emerged as a crucial practice in the software industry, offering significant benefits in time-to-market, and resources management. This is particularly pertinent in web systems development, where the integration of diverse technologies and the varied backgrounds of technical teams pose substantial challenges. The rapid expansion of web systems underscores the urgent need to adopt best practices and methodologies for web system reuse to streamline the development process, reducing effort, cost, and time. This paper aims to identify the key challenges of web system reuse in the context of small and medium-sized software companies in Egypt and Saudi Arabia. Using qualitative research methods, including interviews, focus groups, and participant observations, an empirical study was conducted to examine current reuse practices and understand the root causes of common challenges. Based on the results of the empirical study, a systematic approach was developed to enhance web system reuse during the development process in the context of small and medium-sized software companies in Egypt and Saudi Arabia. The proposed approach addresses critical gaps in current practices, offering practical guidelines to improve efficiency, reduce development time, and enhance overall software quality. This research contributes to the broader discourse on software reuse by providing context-specific insights and adaptable solutions that are relevant to similar markets worldwide.

Application of CRISPR/Cas9 gene-editing technology in Alzheimers disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. It triggers metabolic disorders within the body due to genetic mutations, thus leading to irreversible damage to one's memory and brain. The primary pathogenic features of AD are intracellular neurofibrillary tangles caused by hyperphosphorylated Tau and extracellular amyloid plaques created by the buildup of -amyloid -protein (A). However, up to now, there has been no effective treatment program for Alzheimer's disease. And after a long time of development, many gene editing technologies have been perfected and utilized in practice. Among them, CRISPR-Cas9 technology is the most efficient and practical. As a result, an increasing number of scientists have examined and debated the potential use of CRISPR-Cas9 technology in the management of Alzheimer's disease. This review addresses the use of the CRISPR/Cas9 system to treat Alzheimer's disease and presents the disease's pathophysiology, including the establishment of AD models, genetic screening for the cause of AD, and targeted therapy for AD.

Mind-Body Classroom Strategies: Techniques to Reduce Elementary Student Stress Following Active Shooter Drills

Active shooter drills are widely used in schools throughout the United States, with more than 92% of public schools having an active shooter plan. These drills can increase student stress and anxiety and can have a variety of negative effects, such as somatic complaints, anxiety, poor self-regulation of emotions and behaviors, risk for depression, and prevalence of obesity and eating disorders. This article describes the efficacy of physical activity breaks, mindful breathing techniques, and emotional regulation strategies to reduce stress reactivity and enhance recovery in elementary-age students following active shooter safety drills. A list of example activities is provided for each of the three stress management categories. Each of the activities can be adapted to various developmental levels (i.e., K-12), settings (i.e., classroom, hallway, outdoors), and time availability (i.e., one minute to 10 minutes). The strategies may also be utilized following other emergency drills or during other times of high student and classroom stress.

Is it time for international consensus clinical guidance development for digital papillary adenocarcinoma? : reply to Joshi et al.

Is it time for international consensus clinical guidance development for digital papillary adenocarcinoma? : reply to Joshi et al.

Adolescent close friendships, self-perceived social acceptance, and peer-rated likeability as predictors of wellbeing in young adulthood

IntroductionLinks between interpersonal relationships and physical and psychological functioning have been well-established in the literature. During adolescence, success or distress in peer relationships may have distinct effects on different aspects of wellbeing. The present study aims to examine the ways in which different adolescent peer relationship contexts (i.e., close friendship quality, social acceptance, and likability from peers) can predict outcomes relevant to adult wellbeing (i.e., social anxiety, depression, aggression, social integration, romantic insecurity, job satisfaction, and physical health). Further, the study considers how different developmental stages of adolescence may impact links between peer relationships and wellbeing outcomes.MethodPeer relationship contexts were assessed in early (ages 13–14) and late (ages 17–18) adolescence. Markers of wellbeing were measured in young adulthood (ages 28–30). A path analysis was used to examine whether the developmental timing of adolescent peer relationship contexts could predict wellbeing in young adulthood.ResultsResults suggest that, across adolescence, broader perceived social acceptance may be a more robust predictor of adult wellbeing compared to close friendship quality and peer likability. When examined at early and late adolescence separately, early adolescent social acceptance and late adolescent close friendship quality best predicted outcomes of adult wellbeing.DiscussionImplications and considerations for future research are discussed.

Competition is the main factor, compared to non-lethal threat of predation, affecting life-history traits of Aedes aegypti (Diptera, Culicidae) mosquitoes.

Mosquito larvae coexist with different species of predators in small freshwater bodies. These environments can vary widely in terms of the amount of food and larval densities. Our objective was to understand the impacts of the non-lethal threat of predation, combined with competition effects on Aedes aegypti development and adult life cycle. We tested the effects of two types of non-lethal threat of predation, divided into nine combinations of larvae densities and resource availability on Ae. aegypti larvae. We measured their isolated and combined impacts on larval mortality rate, time to reach pupation, adult size, and lifespan. Real non-lethal threat of predation resulted in a higher larval mortality (71%), compromised the sizes of the individuals (-7%) and prolonged the lifespan (19%) compared to control. Simulated treatment, the anti-predation behaviors led to an increase in larval mortality (21%) compared to the control treatment. Accelerating the larva's development time (-14%) to escape from a dangerous environment severely compromised the size of the individuals (-23%) and increased adult life (10%). The scarcity of food resources, high levels of competition, and non-lethal threat of predation as well, are effective stressors for Ae. aegypti. We observed that resources (food and space) were more important than predation risk for the fitness of the survivors. However, these stressors, individually or combined, can result in high larvae mortality, altered larval development and pupation, affecting the emergence of the adults, with small sizes and altered lifespan, ultimately reducing the fitness of the individuals. © 2024 Society of Chemical Industry.