Population Regulation Research Articles

Rates of Hospital-Based Care among Older Adults in the Community and Residential Care Facilities: A Repeated Cross-Sectional Study.

We examine annual rates of emergency department (ED) visits, hospital admissions, and alternate levels of care (ALC) days (ie, the number of days that an older adult remained in hospital when they could not be safely discharged to an appropriate setting in their community) among older adults. Repeated cross-sectional study. Linked, individual-level health system administrative data on community-dwelling persons, home care recipients, residents of assisted living facilities, and residents of nursing homes aged 65years and older in Ontario, Canada, from January 1, 2013, to December 31,2019. We calculated rates of ED visits, hospital admissions, and ALC days per 1000 individuals per older adult population per year. We used a generalized linear model with a gaussian distribution, log link, and year fixed effects to obtain rate ratios. There were 1,655,656 older adults in the community, 237,574 home care recipients, 42,600 older adults in assisted living facilities, and 94,055 older adults in nursing homes in 2013; there were 2,129,690 older adults in the community, 281,028 home care recipients, 56,975 older adults in assisted living facilities, and 95,925 older adults in nursing homes in 2019. Residents of assisted living facilities had the highest rates of ED visits (1260.692019 vs 1174.912013), hospital admissions (482.632019 vs 480.192013), and ALC days (1905.572019 vs 1443.032013) per 1000 individuals. Residents of assisted living facilities also had significantly higher rates of ED visits [rate ratio (RR) 3.30, 95% CI 3.20, 3.41), hospital admissions (RR 6.24, 95% CI 6.01, 6.47), and ALC days (RR 25.68, 95% CI 23.27, 28.35) relative to community-dwelling older adults. The disproportionate use of ED visits, hospital admissions, and ALC days among residents of assisted living facilities may be attributed to the characteristics of the population and fragmented licensing and regulation of the sector, including variable models of care. The implementation of interdisciplinary, after-hours, team-based approaches to home and primary care in assisted living facilities may reduce the potentially avoidable use of ED visits, hospital admissions, and ALC days among this population and optimize resource allocation in health care systems.

The Chinese Population's Regulation of Emotions for a Healthy Life

Objective: Our aim was to determine the impact of health literacy on the Chinese population's regulation of emotions and the outcomes of such control. Methods: We collected cross-sectional data from the Chinese community (N=1,267) using a Likert scale questionnaire. We employed SPSS to check data normality and made estimations using confirmatory factor analysis and exploratory factor analysis via AMOS. Results: Health literacy significantly influences regulation of emotions. We found that emotions influence mental well-being, forming strong arguments, social relationships, and positive arguments. Conclusions: The Chinese government should provide health literacy opportunities to the public to have a favorable influence on health behavior. Training for the promoting health literacy is important to influence community health behavior. The regulated emotions in the Chinese community can be a way forward to improve health status. Similarly, regulated emotions help to improve arguments for better social relationships.

Density- and size-dependent mechanisms modulate the outcome of stocking in a naturally recruiting freshwater piscivore (northern pike, Esox lucius): A replicated whole-lake experiment

Despite the widespread use of stock enhancements to improve fisheries across the world, there is a lack of robust knowledge under which conditions fish stocking provides additive effects rather than merely replacing a fraction of natural recruitment. Fully controlled and replicated studies at the level of entire ecosystems are needed to provide answers. Properly monitored experimental releases also allow testing mechanisms of density- and size-dependent population regulation. In this study, the population-level outcome of stocking juvenile pike (Esox lucius L.) in naturally reproducing lentic stocks was investigated. We used a replicated before-after-control-impact design in 15 experimental lakes involving two stocking densities and unstocked controls. Releasing age-0 pike failed to generate additive effects at the age-2 cohort. As expected from theory, we observed density-dependent mortality and differential survival of wild and stocked pike. Stocked and wild fishes showed contrasting responses in terms of growth to variation in predator density, competitor density and the forage base, suggesting both subpopulations differed in their response to stocking-induced changes in population traits (e.g., density). Despite the lack of additive effects caused by stocking, a fraction of the stocked individuals established in the stock-enhanced cohort, indicating that replacement of wild recruits by stocked conspecifics had occurred. Depending on the origin of the stocking material, pike stocking thus has the potential for genetic hybridization, while not necessarily benefiting fisheries catch. We conclude that whenever a natural pike population exists, stocking juvenile pike will not produce additive effects in lakes and that enhanced pike populations will be strongly regulated by size- and density-dependent juvenile mortality and less by density-dependent growth.

Isolation and Identification of Entomopathogenic Fungi from Soils of Manipur (N-E India)

Background: Entomopathogenic fungi (EPF) are natural adversaries of insects, serving a crucial role in the regulation of insect pest populations. In response to the growing demand for sustainable agricultural practices that prioritize environmental protection, human safety and animal welfare, the utilization of bio-control agents like entomopathogenic fungi offers a superior and safe alternative to chemical pesticides. Entomopathogenic fungi effectively infect and eliminate insects, thereby contributing to the control of insect populations through the induction of lethal infections known as epizootics. Isolating EPF from the soil is an effective method as they naturally inhabit soil ecosystems. The north-eastern region of India possesses a forest cover exceeding 80%, with Manipur alone accounting for nearly 75% of forest cover in its total geographical area. This abundant forest cover, along with undisturbed land, contributes to the region’s wealth of micro flora and fauna, including a thriving population of entomopathogenic fungi. However, the potential of these fungi in pest population management remains largely unexplored. Therefore, this study was conducted to investigate the diversity of these promising entomopathogenic fungi. Methods: In this study, we isolated fungi from the soils of ten districts of Manipur and identified several isolates with entomopathogenic properties. Soil bating using Galleria mellonella larvae was employed for the isolation of entomopathogenic fungi. Result: A total of 73 fungal isolates were obtained from 100 soil samples, out of which 54 were identified as entomopathogenic fungi. The genus Aspergillus constituted the most commonly isolated entomopathogenic fungi, followed by isolates of Beauveria, Clonostachys, Talaromyces, Trichoderma, Fusarium, Aspergillus, Candida and Meyerozyma genera. Diversity studies revealed variations in the types and proportions of fungi among different regions of Manipur. Pathogenicity tests confirmed the virulence of the isolated entomopathogenic fungi, with 14 isolates of Beauveria bassiana and two isolates of Talaromyces purpureogenus causing 100% mortality of the test insects. The isolated fungi exhibited excellent performance in insect control and could be further mass-produced for effective pest management.

Population Regulation and Density-Dependent Demography in the Trinidadian Guppy.

AbstractClassic theory for density-dependent selection for delayed maturation requires that a population be regulated through some combination of adult fecundity and/or juvenile survival. We tested whether those demographic conditions were met in four experimental populations of Trinidadian guppies in which delayed maturation of males evolved when the densities of those populations became high. We used monthly mark-recapture data to examine population dynamics and demography in these populations. Three of the four populations displayed clear evidence of regulation. In all four populations, monthly adult survival rates were independent of biomass density or actually increased with increased biomass density. Juvenile recruitment, which is a combination of adult fecundity and juvenile survival, decreased as biomass density increased in all four populations. Demography showed marked seasonality, with greater survival and higher recruitment in the dry season than the wet season. Population regulation via juvenile recruitment supports the hypothesis that density-dependent selection was responsible for the evolution of delayed maturity in males. This body of work represents one of the few complete tests of density-dependent selection theory.

Extracts of Talaromyces purpureogenus Strains from Apis mellifera Bee Bread Inhibit the Growth of Paenibacillus spp. In Vitro.

Honey bees coexist with fungi that colonize hive surfaces and pollen. Some of these fungi are opportunistic pathogens, but many are beneficial species that produce antimicrobial compounds for pollen conservation and the regulation of pathogen populations. In this study, we tested the in vitro antimicrobial activity of Talaromyces purpureogenus strains isolated from bee bread against Paenibacillus alvei (associated with European foulbrood disease) and three Aspergillus species that cause stonebrood disease. We found that methanol extracts of T. purpureogenus strains B18 and B195 inhibited the growth of P. alvei at a concentration of 0.39 mg/mL. Bioactivity-guided dereplication revealed that the activity of the crude extracts correlated with the presence of diketopiperazines, a siderophore, and three unknown compounds. We propose that non-pathogenic fungi such as Talaromyces spp. and their metabolites in bee bread could be an important requirement to prevent disease. Agricultural practices involving the use of fungicides can disrupt the fungal community and thus negatively affect the health of bee colonies.

Biological control of hemlock woolly adelgid in North America: History, status, and outlook

The hemlock woolly adelgid (HWA, Adelges tsugae, Hemiptera: Adelgidae) is an invasive insect that threatens the ability to maintain eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) as ecologically functional components of eastern North American forests. Since the early 1990 s, a classical biological control program for HWA has been pursued using insect predators from regions of Asia and western North America where the adelgid is native. Early efforts to establish ladybird beetles (Coleoptera: Coccinellidae) resulted in the establishment of Sasajiscymnus tsugae from Japan, but consistently poor field recovery of this species suggests it has not been an effective biocontrol agent in the introduced range. Two additional ladybird beetles, Scymnus ningshanensis Yu & Yao, and S. camptodromus Yu & Liu, were released but did not establish. Subsequent introduction, widespread establishment and spread of Laricobius nigrinus and La. osakensis (Coleoptera: Derodontidae) has provided substantial predation on winter stages of HWA, but has not provided overall regulation of adelgid populations below levels that cause hemlock shoot growth loss and mortality. Recently, efforts have focused on prey-specific genetic lineages of Leucotaraxis argenticollis and Le. piniperda (Diptera: Chamaemyiidae), which co-occur with La. nigrinus in their native range of the Pacific Northwest and show promise for eventual establishment in eastern North America. This review provides a brief introduction on the ecology, evolution, and population dynamics of HWA and its hosts, detailed coverage of the predators that have been (and are being) evaluated as biological control agents, and a discussion of the overall biological program with considerations for its future implementation.

Coupled Oscillators in an Agroecosystem: Integrating Direct and Indirect Effects.

AbstractAgricultural pests are increasingly appreciated as subjects of ecology. One particular case, a pest in coffee production, is analyzed here using the conceptual framework of complex systems, increasingly acknowledged as having an obvious home in the field of ecology, notorious for its complex structures. The particular case analyzed here arguably falls under the control of the complexity of the ecological system rather than of a simple magic bullet of population regulation. The system, which has been under study in southern Mexico for the past quarter century, is analyzed through the lens of neutral oscillations of the classical nondissipative Lotka-Volterra system. Based on three consumer/resource pairs (populations of [1] an ant, [2] a scale insect, [3] a beetle predator of the scale insect, [4] a fungal pathogen of the scale insect, and [5] a fly parasitoid of the ant), this five-dimensional system is well known qualitatively. Coupling all agents through both direct effects and trait-mediated indirect effects, the behavior of the neutral oscillation form of the system reveals a complex set of behaviors, including harmonized invariant sets, chaos, and/or quasiperiodicity. Such behaviors are well-known subjects in the science of complex systems and, it is argued, are ultimately sufficient to effect a degree of regulation on the pest, independent of explicit density-dependent feedback. Control of the system is thus seen as arguably actuated through its complexity, independent of any classic dissipative force.

Assessing microhabitat, landscape features and intraguild relationships in the occupancy of the enigmatic and threatened Andean tiger cat (Leopardus tigrinus pardinoides) in the cloud forests of northwestern Colombia.

Mesocarnivores play a key role in ecosystem dynamics through the regulation of prey populations and are sensitive to environmental changes; thus, they are often considered good model organisms for conservation planning. However, data regarding the factors that influence the habitat use of threatened small wild felids such as the Andean tiger cat (Leopardus tigrinus pardinoides) are scarce. We conducted a two-year survey with 58 camera trap stations to evaluate the determinants of Andean tiger cat habitat use in three protected areas in the Middle Cauca, Colombia. We developed site occupancy models and found that Andean tiger cat habitat use increased with leaf litter depth at intermediate elevations and far from human settlements. Through conditional cooccurrence models, we found that Andean tiger cat habitat use was invariant to the presence of prey or potential intraguild competitors and killers/predators, but its detectability increased when they were present and detected. This suggests that Andean tiger cats may be more likely to be detected in sites with high prey availability. We found that Andean tiger cats preferred sites with deep leaf litter, which is a particular feature of cloud forests that provides suitable conditions for ambush hunting and hiding from intraguild enemies. Our results showed that Andean tiger cats avoided human settlements, which may minimize potential mortality risks in those areas. Moreover, the restricted use of middle elevations by Andean tiger cats suggested that they could be used as a sentinel species to track the effects of climate change since their suitable habitat is likely to be projected upward in elevation. Future conservation actions must be focused on identifying and mitigating human-related threats close to the Andean tiger cat habitat while preserving microhabitat conditions and the existing networks of protected areas.

Effects of Madagascar marine reserves on juvenile and adult coral abundance, and the implication for population regulation

Recruitment is a critical component in the dynamics of coral assemblages, and a key question is to determine the degree to which spatial heterogeneity of adults is influenced by pre-vs. post-settlement processes. We analyzed the density of juvenile and adult corals among 18 stations located at three regions around Madagascar, and examined the effects of Marine Protected Areas (MPAs). Our survey did not detect a positive effect of MPAs on juveniles, except for Porites at the study scale. The MPA effect was more pronounced for adults, notably for Acropora, Montipora, Seriatopora, and Porites at the regional scale. For most dominant genera, densities of juveniles and adults were positively correlated at the study scale, and at least at one of the three regions. These outcomes suggest recruitment-limitation relationships for several coral taxa, although differences in post-settlement events may be sufficiently strong to distort the pattern established at settlement for other populations. The modest benefits of MPAs on the density of juvenile corals demonstrated here argue in favor of strengthening conservation measures more specifically focused to protect recruitment processes.

Sublethal granulovirus infections in the tomato leafminer,Tuta absoluta: transmission and population‐level effects

AbstractGranuloviruses are insect viruses commonly used as biological insecticides for pest control in agriculture. Most pest control programs rely on the most virulent strains and doses to cause acute mortality events. However, we hypothesize that sublethal infections are key to maintaining persistent epidemics that regulate pest populations in the long‐term. The tomato leafminer (TLM),Tuta absoluta(Meyrick) (=Phthorimaea absolutaMeyrick) (Lepidoptera: Gelechiidae), is one of the most limiting pests of greenhouse and field tomatoes. Previous efforts have identified a strain ofPhthorimaea operculellagranulovirus (PhopGV), coded VG013, associated with field populations of the TLM, which causes significant acute mortalities and is being used as active ingredient of a biological insecticide. The aim of this study was to determine the effect of sublethal infections and transmission mechanisms of PhopGV‐VG013 on TLM populations. Six viral doses were tested for their virulence and effects on TLM development rate, and intrinsic population growth rate. A sublethal dose was selected to compare the density‐dependent mortality of TLM populations and vertical transmission was examined by testing for PhopGV in the offspring of surviving infected individuals. Horizontal transmission was assessed by testing for PhopGV in frass of infected larvae, and the infection of virus‐free larvae confined with infected larvae in the same leaf. We found that sublethal doses of PhopGV have slight effects on TLM population growth rates, and none on the strength of density‐dependent mortality. Although we found for the first time that PhopGV‐VG013 is transmitted to approximately 7.5% of the offspring of individuals that survive the virus challenge, we found no evidence suggesting horizontal transmission from sublethal infections. Our results show that sublethal infections of highly virulent ganulovirus strains may favor long‐term pathogen persistence but have a limited role in host population regulation.

The Level of Development of the Socio-Economic Indicators of the Abay Region: Methods and Analysis

This descriptive work is aimed at studying at the micro level the socio-demographic indicators of the Abay region of Kazakhstan. The literature review highlights the importance of population dynamics, education, health care and internal migration for sustainable development in the region and in the country. The study also uses the fuzzy set method for several aspects of the selected indicators. Secondary data for 2010-2020 are taken from an open source - the Bureau of National Statistics and were used to identify negative trends and contradictions. The results showed that over the past 10 years there are negative trends in the region in terms of indicators: a high level of emigration, a shortage of able-bodied population, an increase in the number of schoolchildren with a constant number of schools, and a negative trend in hospital organizations. Beskaragai and Borodulikha districts natural population growth decreased by 62 percent. The number of schools in the region has slightly decreased, while in Semey (23%), Kurchatov district (30%) and Ayagoz (1.54%) district there is an increase in school enrollment. In Abay and Kokpekty districts, there is a decrease in the number of schools enrollment (-10% and -16%). The number of hospital beds has decreased significantly in most districts (more than 30 percent in half of the districts). In general, this article contributes to a deeper understanding of the socio-demographic dynamics of the Abai region. The results obtained can be used in making political decisions related to population regulation and economic development in each region.

Ecological factors shaping the ectoparasite community assembly of the Azara's Grass Mouse, Akodon azarae (Rodentia: Cricetidae).

Parasites are integral members of the global biodiversity. They are useful indicators of environmental stress, food web structure and diversity. Ectoparasites have the potential to transmit vector-borne diseases of public health and veterinary importance and to play an important role in the regulation and evolution of host populations. The interlinkages between hosts, parasites and the environment are complex and challenging to study, leading to controversial results. Most previous studies have been focused on one or two parasite groups, while hosts are often co-infected by different taxa. The present study aims to assess the influence of environmental and host traits on the entire ectoparasite community composition of the rodent Akodon azarae. A total of 278 rodents were examined and mites (Mesostigmata), lice (Phthiraptera), ticks (Ixodida) and fleas (Siphonaptera) were determined. A multi-correspondence analysis was performed in order to analyze interactions within the ectoparasite community and the influence of environmental and host variables on this assembly. We found that environmental variables have a stronger influence on the composition of the ectoparasite community of A. azarae than the host variables analyzed. Minimum temperature was the most influential variable among the studied. In addition, we found evidence of agonistic and antagonistic interactions between ticks and mites, lice and fleas. The present study supports the hypothesis that minimum temperature plays a major role in the dynamics that shape the ectoparasite community of A. azarae, probably through both direct and indirect processes. This finding becomes particularly relevant in a climate change scenario.

Enhanced amygdala–cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation

Sleep loss robustly disrupts mood and emotion regulation in healthy individuals but can have a transient antidepressant effect in a subset of patients with depression. The neural mechanisms underlying this paradoxical effect remain unclear. Previous studies suggest that the amygdala and dorsal nexus (DN) play key roles in depressive mood regulation. Here, we used functional MRI to examine associations between amygdala- and DN-related resting-state connectivity alterations and mood changes after one night of total sleep deprivation (TSD) in both healthy adults and patients with major depressive disorder using strictly controlled in-laboratory studies. Behavioral data showed that TSD increased negative mood in healthy participants but reduced depressive symptoms in 43% of patients. Imaging data showed that TSD enhanced both amygdala- and DN-related connectivity in healthy participants. Moreover, enhanced amygdala connectivity to the anterior cingulate cortex (ACC) after TSD associated with better mood in healthy participants and antidepressant effects in depressed patients. These findings support the key role of the amygdala-cingulate circuit in mood regulation in both healthy and depressed populations and suggest that rapid antidepressant treatment may target the enhancement of amygdala-ACC connectivity.

Condensations on electrowetting surfaces: An electrostatic liquid conveyor from dropwise-filmwise competition

In contrast to the traditional point of view, electrowetting creates a dynamic wetting regime. Hydrophilicity can penetrate or recede from the working surface –depending on the liquid locale rather than the substrate structures. Size regulation forms droplet clusters as condensation accumulates. Coalescence cascades and mass imbalances transfer the liquid from one zone to the next. What ensues is a passive electrostatic liquid conveyor that takes the condensation away from its constant self-stagnating cycles. Each working zone functions independently from one another according to its intended purpose: nucleation and diffusion, accumulation and collection. 40 to 50 percent of the increase in liquid recovery traces its root to the spatial-size regulation of the droplet population. Simultaneously, the gain from higher nucleations runs parabolically with electrostatic voltage. The competition between dropwise and filmwise tendencies determines the migration of condensates. Yet, the autonomy of the two means that nucleations are direct and unhindered as to how high an electrostatic voltage can be: the only limit is the material strength and endurance to sustain this concentration of electric potentials.

Plant diversity and ecological intensification in crop production systems

AbstractEcological intensification (EI) is the enhancement of ecosystem services to complement or substitute for the role of anthropogenic inputs in maintaining or increasing yields. EI has potential to increase farming’s environmental sustainability, e.g. reducing environmentally harmful management activities while sustaining yields. EI is based upon ecological processes which in turn are influenced by biodiversity. We review how biodiversity, particularly vascular plant diversity, can regulate ecosystem processes relevant to EI at multiple spatial scales. At an individual plant genotype level, complementarity in functional traits has a direct impact on productivity. At in-field, population level, mixtures of crop types confer resilience to minimize the risk of pest and disease incidence and spread. Scaling up to the field level, a diversity of non-crop plants (i.e. weeds) provides resources necessary for in-field functional processes, both below ground (carbon inputs, decomposition) and above ground (resource continuity for pollinators and natural enemies). At the landscape scale, mosaics of semi-natural and managed vegetation provide buffers against extreme events through flood and drought risk mitigation, climate amelioration and pest population regulation. Overall this emphasizes the importance of heterogeneity across scales in maintaining ecosystem functions in farmland. Major research challenges highlighted by our review include the need: to better integrate plant functional diversity (from traits to habitat scales) into cropping system design; to quantify the (likely interactive) contribution of plant diversity for effective EI relative to other management options; and to optimize through targeted management the system function benefits of biodiversity for resilient, efficient and productive agroecosystems.

Characterization of Chemotaxis-Associated Gene Dysregulation in Myeloid Cell Populations in the Lungs during Lipopolysaccharide-Mediated Acute Lung Injury.

During endotoxin-induced acute lung injury (ALI), immune cell recruitment resulting from chemotaxis is mediated by CXC and CC chemokines and their receptors. In this study, we investigated the role of chemokines and their receptors in the regulation of myeloid cell populations in the circulation and the lungs of C57BL/6J mice exhibiting LPS-mediated ALI using single-cell RNA sequencing. During ALI, there was an increase in the myeloid cells, M1 macrophages, monocytes, neutrophils, and other granulocytes, whereas there was a decrease in the residential alveolar macrophages and M2 macrophages. Interestingly, LPS triggered the upregulation of CCL3, CCL4, CXCL2/3, and CXCL10 genes associated with cellular migration of various subsets of macrophages, neutrophils, and granulocytes. Furthermore, there was an increase in the frequency of myeloid cells expressing CCR1, CCR3, CCR5, and CXCR2 receptors during ALI. MicroRNA sequencing studies of vehicle versus LPS groups identified several dysregulated microRNAs targeting the upregulated chemokine genes. This study suggests that chemokine ligand-receptors interactions are responsible for myeloid cell heterogenicity and cellular recruitment to the lungs during ALI. The single-cell transcriptomics allowed for an in-depth assessment and characterization of myeloid cells involved in immune cell trafficking during ALI.

Photo-Response with Radical Afterglow by Regulation of Spin Populations and Hole-Electron Distributions.

No matter photoinduced organic radicals have been reported frequently, they are usually non-luminescent at ambient conditions. The internal mechanism on stability and electronic transitions of photoinduced radicals, is thus crucial for the development of relevant materials. Herein, a series of photoinduced radical emission systems were developed conveniently through doping benzoic acids into the hydrogen donor polyvinyl alcohol (PVA) matrix. Visual photoinduced radical emission and photochromism could be observed on Ph-3COOH@PVA film with the formation of cyclohexadienyl-type structure. For the first time, radical afterglow appeared with energy transfer from triplet state. The appropriate introduction of carboxylic groups to three nonadjacent carbon atoms on the benzene ring was the best for decreasing spin population and promoting electronic transitions of the radical. This study largely expands the radical emission property from both internal mechanism and practical application.

Photo‐Response with Radical Afterglow by Regulation of Spin Populations and Hole‐Electron Distributions

AbstractNo matter photoinduced organic radicals have been reported frequently, they are usually non‐luminescent at ambient conditions. The internal mechanism on stability and electronic transitions of photoinduced radicals, is thus crucial for the development of relevant materials. Herein, a series of photoinduced radical emission systems were developed conveniently through doping benzoic acids into the hydrogen donor polyvinyl alcohol (PVA) matrix. Visual photoinduced radical emission and photochromism could be observed on Ph‐3COOH@PVA film with the formation of cyclohexadienyl‐type structure. For the first time, radical afterglow appeared with energy transfer from triplet state. The appropriate introduction of carboxylic groups to three nonadjacent carbon atoms on the benzene ring was the best for decreasing spin population and promoting electronic transitions of the radical. This study largely expands the radical emission property from both internal mechanism and practical application.

PRESENCIA DE HONGOS ENTOMOPATÓGENOS ASOCIADOS A SUELOS CULTIVADOS CON AGUACATE (Persea americana Mill.) EN COLIMA, MÉXICO

<p><strong>Background: </strong>Entomopathogenic fungi (EF) play a key role in the regulation of arthropod populations and biotransformation in natural systems, as well as biological pest control agents in different agroecosystems, including avocado cultivation (<em>Persea americana</em> Mill.), where Mexico is a leader in production and export worldwide.<strong> Objective</strong>: Determine the presence of EF in soil in commercial avocado orchards in the state of Colima, Mexico. <strong>Methodology</strong>: Sampling was carried out in three avocado orchards (Piedra rajada, El Guardián, and Montitlán) located in Comala and Cuauhtémoc in the state of Colima, Mexico, from July 2016 to June 2017. Soil samples were collected around avocado trees. Isolation of entomopathogenic fungi was performed using the <em>Galleria mellonella</em> Linnaeus insect trap technique. The isolates were identified considering their micro- and macroscopic characteristics with the taxonomic keys of Humber (2012). <strong>Results</strong>: A total of 108 samples were collected, of those, 120 isolates were obtained, of which 112 belong to the genus <em>Metarhizium</em> and eight to <em>Beauveria</em>. <strong>Implications</strong>: The recovered fungi have a great value for the avocado-growing areas of the state of Colima, either for the conservation of natural enemies of soil pests or for their potential use as an alternative to synthetic insecticides. <strong>Conclusion</strong>: Knowing the native micro-biota of the soil should be considered within biological pest control strategies, since it allows selecting the best adapted species, and including sustainable alternatives for the environment. </p>