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1.
Sci Rep ; 12(1): 2340, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35149696

RESUMO

The western corn rootworm is an invasive species to Europe and is a major agricultural pest that causes widespread economic and yield losses to maize producers. The Gompertz curve was originally used to model human population mortality. It is a sigmoidal curve where the beginning and end of a period shows the slowest time for growth, and adequately describes observed dynamics of many phenomena. We propose the use of the Gompertz function in a Bayesian Hierarchical framework to model the emergence dynamics of the western corn rootworm beetle. The proposed model includes the use of climatic variables to assess how weather can influence the observed dynamics. We apply the model to Austrian monitoring data collected in 2004-2015.


Assuntos
Besouros/crescimento & desenvolvimento , Modelos Biológicos , Animais , Teorema de Bayes , Clima , Conjuntos de Dados como Assunto , Masculino , Dinâmica Populacional , Temperatura
2.
J Therm Biol ; 101: 103001, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34879907

RESUMO

Modeling the impact of temperature on each life stage of a beetle population represents a continuing challenge. This study evaluates the effects of five temperature treatments (20, 23, 26, 29 and 32 °C) on population abundance and timing of a colony of ambrosia beetles Xyleborus affinis reared under laboratory conditions and use this data to develop demographic and phenological models. Abundances at each life stage (eggs, larvae, pupae and adult) were examined through periodic destructive sampling; given that it was not possible to track individuals. To assess the effects of temperature on oviposition, development and survival rates we developed a novel estimation strategy based on cohorts, which does not require individual developmental data. Since oviposition was entirely unwitnessed, we assessed competing empirical ovipositional models. Rates of development were computed using a modal rate curve for each life stage, and rates were projected to cohorts in life stages assuming log-normal developmental variance. Temperature-driven survival rates were assumed to be logistic with a quadratic exponent to capture modal temperature dependence. Parameters were estimated simultaneously using minimum negative log posterior likelihood, assuming Poisson distribution of observations and using priors to inform unobserved developmental rates and enforce mechanistic constraints on oviposition models. A parabolic function best described oviposition rate. Optimal developmental temperatures were 30.5 °C, 29 °C and 27.5 °C, with maximum developmental rates of 0.26/day, 0.12/day and 0.23/day for eggs, larvae and pupae, respectively. The survival rates in the range 20-29 °C were equal to 1 in the eggs-to-larvae transition, from 0.72 to 0.35 in larvae-to-pupae transition, and from 0.2 to 0.89 in pupae-to-adults transition. This procedure effectively characterized the direct thermal effects on development and survival of each life stage in the X. affinis under laboratory conditions and would be suitable for estimating temperature dependence for other species in which individual observations are not possible.


Assuntos
Besouros , Modelos Teóricos , Temperatura , Animais , Besouros/crescimento & desenvolvimento , Besouros/fisiologia , Feminino , Laboratórios , Estágios do Ciclo de Vida , Oviposição , Densidade Demográfica
3.
PLoS One ; 16(12): e0260532, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34928980

RESUMO

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major maize pest in the United States causing significant economic loss. The emergence of field-evolved resistant WCR to Bacillus thuringiensis (Bt) traits has prompted the need to discover and deploy new insecticidal proteins in transgenic maize. In the current study we determined the crystal structure and mode of action (MOA) of the Vpb4Da2 protein (formerly known as Vip4Da2) from Bt, the first identified insecticidal Vpb4 protein with commercial level control against WCR. The Vpb4Da2 structure exhibits a six-domain architecture mainly comprised of antiparallel ß-sheets organized into ß-sandwich layers. The amino-terminal domains 1-3 of the protein share structural homology with the protective antigen (PA) PA14 domain and encompass a long ß-pore forming loop as in the clostridial binary-toxB module. Domains 5 and 6 at the carboxyl-terminal half of Vpb4Da2 are unique as this extension is not observed in PA or any other structurally-related protein other than Vpb4 homologs. These unique Vpb4 domains adopt the topologies of carbohydrate-binding modules known to participate in receptor-recognition. Functional assessment of Vpb4Da2 suggests that domains 4-6 comprise the WCR receptor binding region and are key in conferring the observed insecticidal activity against WCR. The current structural analysis was complemented by in vitro and in vivo characterizations, including immuno-histochemistry, demonstrating that Vpb4Da2 follows a MOA that is consistent with well-characterized 3-domain Bt insecticidal proteins despite significant structural differences.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/química , Inseticidas/farmacologia , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Cristalografia por Raios X , Inseticidas/química , Intestinos/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Mutagênese Sítio-Dirigida , Multimerização Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Zea mays/metabolismo , Zea mays/parasitologia
4.
Toxins (Basel) ; 13(11)2021 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-34822531

RESUMO

The insect integument (exoskeleton) is an effective physiochemical barrier that limits disease-causing agents to a few portals of entry, including the gastrointestinal and reproductive tracts. The bacterial biopesticide Bacillus thuringiensis (Bt) enters the insect host via the mouth and must thwart gut-based defences to make its way into the body cavity (haemocoel) and establish infection. We sought to uncover the main antibacterial defences of the midgut and the pathophysiological features of Bt in a notable insect pest, the Colorado potato beetle Leptinotarsa decemlineata (CPB). Exposing the beetles to both Bt spores and their Cry3A toxins (crystalline δ-endotoxins) via oral inoculation led to higher mortality levels when compared to either spores or Cry3A toxins alone. Within 12 h post-exposure, Cry3A toxins caused a 1.5-fold increase in the levels of reactive oxygen species (ROS) and malondialdehyde (lipid peroxidation) within the midgut - key indicators of tissue damage. When Cry3A toxins are combined with spores, gross redox imbalance and 'oxidation stress' is apparent in beetle larvae. The insect detoxification system is activated when Bt spores and Cry3A toxins are administered alone or in combination to mitigate toxicosis, in addition to elevated mRNA levels of candidate defence genes (pattern-recognition receptor, stress-regulation, serine proteases, and prosaposin-like protein). The presence of bacterial spores and/or Cry3A toxins coincides with subtle changes in microbial community composition of the midgut, such as decreased Pseudomonas abundance at 48 h post inoculation. Both Bt spores and Cry3A toxins have negative impacts on larval health, and when combined, likely cause metabolic derangement, due to multiple tissue targets being compromised.


Assuntos
Toxinas de Bacillus thuringiensis/fisiologia , Bacillus thuringiensis/fisiologia , Besouros/microbiologia , Endotoxinas/fisiologia , Proteínas Hemolisinas/fisiologia , Controle de Insetos , Controle Biológico de Vetores , Esporos Bacterianos/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Longevidade
5.
Sci Rep ; 11(1): 20699, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34667179

RESUMO

The non-persistent impact of biocontrol agents can be revealed for pest control when associated entomopathogenic fungi (EPFs) negatively affect the natural enemies. In this assay, impacts of Beauvaria bassiana (Balsamo) Vuillemin, and Metarhizium anisopliae (Metschnikoff) Sorokin were studied for their compatibility or side effects on life table parameters of an important generalist predator, Coccinella septempunctata L. The results indicated non-significant impacts of both EPFs on life table parameters of C. septempunctata. The development time (egg-adult) was not significantly different in control (69.79 days) and EPFs treated C. septempunctata (69.35-80.07 days). Both fungi did not induce any significant changes in the fecundity, adult pre-oviposition period (APOP), total preoviposition period (TPOP), and mean generation time (T) as compared to control treatment. Similarly, no difference in fecundity rate of C. septempunctata was observed after EPFs treatment (287.7-288.5) compared to control (290.0). The highest net reproductive rate (R0) occurred in control (87.05 offspring individual-1) and M. anisopliae (86.31 offspring individual-1) as compared to B. bassiana treated beetles (76.97 offspring individual-1). The age-specific fecundity curves indicated that the C. septempunctata had a similar fecundity rate in both EPFs treatments and control. This study demonstrates no significant side effects of B. bassiana and M. anispoliae on the performance and biology of C. septempunctata. Considering the compatibility of both EPFs with C. septempunctata, their combinations can be recommended in various integrated pest management programs.


Assuntos
Besouros/crescimento & desenvolvimento , Besouros/microbiologia , Fungos/patogenicidade , Animais , Feminino , Fertilidade/fisiologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Tábuas de Vida , Masculino , Controle de Pragas/métodos , Controle Biológico de Vetores/métodos , Reprodução/fisiologia
6.
Sci Rep ; 11(1): 20496, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34650106

RESUMO

Cereal leaf beetle (CLB, Oulema melanopus, Coleoptera, Chrysomelidae) is a serious agricultural pest that causes considerable damages to agricultural production. The aim of this study was to characterize the bacterial communities associated with larvae and imagoes of CLB collected from various cereal host species and locations. The bacterial profile was characterized by 16S rRNA gene sequencing at the V3-V4 hypervariable region. Using taxonomy-based analysis, the bacterial community of CLB containing 16 phyla, 26 classes, 49 orders, 78 families, 94 genera, and 63 species of bacteria was identified. The abundance of Wolbachia, Rickettsia, and Lactococcus genus was significantly higher in CLB imagoes than in larvae. Statistical analysis confirmed that the bacterial community of the larvae is more diverse in comparison to imagoes and that insects collected from spring barley and wheat are characterized by a much higher biodiversity level of bacterial genera and species than insects collected from other cereals. Obtained results indicated that the developmental stage, the host plant, and the insect's sampling location affected the CLB's microbiome. Additionally, the CLB core microbiome was determined. It consists of 2 genera (Wolbachia and Rickettsia) shared by at least 90% tested CLB insects, regardless of the variables analysed.


Assuntos
Bactérias/isolamento & purificação , Besouros/microbiologia , Microbiota , Animais , Bactérias/classificação , Bactérias/genética , Besouros/crescimento & desenvolvimento , Hordeum , Larva/microbiologia , RNA Ribossômico 16S , Rickettsia/isolamento & purificação , Triticum , Wolbachia/isolamento & purificação
7.
Pak J Biol Sci ; 24(6): 688-698, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34486345

RESUMO

<b>Background and Objective:</b> Control of the stored date insects by an eco-friendly method is essential to maintain the fruit for prolonged periods, especially that dates are eaten fresh. The search for a safe method, as an alternative to commonly used chemical pesticides, is needed. The objective is to investigate CO<sub>2</sub> enriched atmosphere on the Mortality Percentage (MP) of the Saw-toothed grain beetle, <i>O. surinamensis</i>, life stages with special emphasis on reducing damage to stored dates. <b>Materials and Methods:</b> The effect of high levels of CO<sub>2</sub> as an alternative control method against the Saw-toothed grain beetle, <i>Oryzaephilus surinamensis</i> L., at different life stages was studied on infested 'Saqie' dates. Four CO<sub>2</sub> pressures (25, 50, 75 and 90 kPa, balance is nitrogen) were tested for 6, 12, 18, 24, 48, 72 and 96 hrs intervals. The response of different life stages of <i>O. surinamensis</i> to the different treatments varied according to CO<sub>2</sub> level, developmental stage and exposure period. <b>Results:</b> Mortality (%) was higher during the larval stage, followed by adults, pupae and eggs, in descending order. The larvae and adult stages were more sensitive to CO<sub>2</sub> treatment than the pupal and egg. Exposure time was more effective on eggs, larval and adult MP than the CO<sub>2</sub> atmosphere level. Mortality% at 96 hrs exposure time was almost 100% with CO<sub>2</sub> atmospheres of 50, 75 and 90 kPa. Mathematical equations were developed to model the relationship between mortality% and CO<sub>2</sub> treatments using multiple regression analyses for each life stage. <b>Conclusion:</b> The results confirmed that CO<sub>2</sub> could be applied to final food products during packaging to control the residual occurrence of insect pests after storage and before the packaging process to prevent further infestation in the final packages.


Assuntos
Dióxido de Carbono/farmacologia , Besouros/efeitos dos fármacos , Embalagem de Alimentos , Parasitologia de Alimentos , Armazenamento de Alimentos , Frutas/parasitologia , Inseticidas/farmacologia , Phoeniceae/parasitologia , Animais , Besouros/crescimento & desenvolvimento , Estágios do Ciclo de Vida
8.
J Therm Biol ; 100: 103043, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503790

RESUMO

Temperature plays an important role in different biological activities of organisms. The relationship between temperature and insect development has long been recognized as an important environmental parameter in modeling insect population dynamics. Although few studies have investigated the existence of developmental rate polymorphism within a cohort, the role of abiotic and biotic factors on such developmental variation has so far been meagerly investigated. The present study was designed to investigate the effect of thermal extremes on the developmental rate polymorphism and its influence on reproductive potential of Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae). The study will also be helpful in solving hitherto whether the existence of slow and fast developers within a cohort has a purely genetic basis or this developmental polymorphism is presided by environmental factors. Our result reveals a clear bimodal pattern of distribution with two peaks at each temperature (20, 25, 27, 30 and 35 °C) where the first peak represents the fast developers and second peak represents the slow developers. Both developmental variants took the longest duration for development at 20 °C followed by 25, 27, 30 °C and minimum at 35 °C. More fast developers were found at higher temperatures. Slow developing individuals were heavier than the fast developing individuals regardless of rearing temperature. Slow developers have higher reproductive success in terms of fecundity and egg viability than the fast developers. The results of this study denote the constancy of the developmental rate polymorphism within a cohort and the possibility that this polymorphism was owing to the exogenous cues inclined differential rates of mortality.


Assuntos
Besouros/crescimento & desenvolvimento , Variação Genética , Resposta ao Choque Térmico , Estágios do Ciclo de Vida , Animais , Besouros/genética , Besouros/fisiologia , Feminino , Masculino , Reprodução , Caracteres Sexuais
9.
Sci Rep ; 11(1): 19377, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588559

RESUMO

Coleoptera are currently considered a fundamental tool to help solve criminal investigations, allowing forensic entomologists to estimate post-mortem intervals and obtain other ecology-related information. Thanatophilus rugosus (Linnaeus, 1758) is an important necrophagous beetle distributed through most of the Palaearctic region, where it is readily found on human bodies and animal carcasses. In this study, the new thermal summation models for all the developmental stages of Thanatophilus rugosus are provided. Beetles were reared at six different constant and ecologically relevant temperatures (12, 14, 16, 18, 20, and 22 °C), and their developmental times were measured. Thermal summation constants were calculated for each developmental stage (egg, three larval instars, post-feeding stage, and pupa).


Assuntos
Besouros/crescimento & desenvolvimento , Entomologia Forense/métodos , Animais , Comportamento Alimentar , Temperatura
10.
PLoS One ; 16(9): e0255660, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34555059

RESUMO

Nicrophorus is a genus of beetles that bury and transform small vertebrate carcasses into a brood ball coated with their oral and anal secretions to prevent decay and that will serve as a food source for their young. Nicrophorus pustulatus is an unusual species with the ability to overtake brood of other burying beetles and whose secretions, unlike other Nicrophorus species, has been reported not to exhibit antimicrobial properties. This work aims to better understand how the presence or absence of a food source influences the expression of genes involved in the feeding process of N. pustulatus. To achieve that, total RNA was extracted from pooled samples of salivary gland tissue from N. pustulatus and sequenced using an Illumina platform. The resulting reads were used to assemble a de novo transcriptome using Trinity. Duplicates with more than 95% similarity were removed to obtain a "unigene" set. Annotation of the unigene set was done using the Trinotate pipeline. Transcript abundance was determined using Kallisto and differential gene expression analysis was performed using edgeR. A total of 651 genes were found to be differentially expressed, including 390 upregulated and 261 downregulated genes in fed insects compared to starved. Several genes upregulated in fed beetles are associated with the insect immune response and detoxification processes with only one transcript encoding for the antimicrobial peptide (AMP) defensin. These results confirm that N. pustulatus does not upregulate the production of genes encoding AMPs during feeding. This study provides a snapshot of the changes in gene expression in the salivary glands of N. pustulatus following feeding while providing a well described transcriptome for the further analysis of this unique burying beetle.


Assuntos
Besouros/genética , Comportamento Alimentar , Alimentos , Regulação da Expressão Gênica , Proteínas de Insetos/genética , Glândulas Salivares/metabolismo , Transcriptoma , Animais , Secreções Corporais , Besouros/crescimento & desenvolvimento , Proteínas de Insetos/metabolismo
11.
Sci Total Environ ; 799: 149377, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34364282

RESUMO

Present-day disturbances are transforming European forest landscapes, and their legacies determine the vulnerability and resilience of the emergent forest generation. To understand these legacy effects, we investigated the resilience of the aboveground forest biomass (Babg) to a sequence of disturbances affecting the forest in different recovery phases from the initial large-scale impact. We used the model iLand to simulate windthrows that affected 13-24% of the Babg in a Central European forest landscape. An additional wind event was simulated 20, 40, 60, or 80 years after the initial impact (i.e., sequences of two windthrows were defined). Each windthrow triggered an outbreak of bark beetles that interacted with the recovery processes. We evaluated the resistance of the Babg to and recovery after the impact. Random Forest models were used to identify factors influencing resilience. We found that Babg resistance was the lowest 20 years after the initial impact when the increased proportion of emergent wind-exposed forest edges prevailed the disturbance-dampening effect of reduced biomass levels and increased landscape heterogeneity. This forest had a remarkably high recovery rate and reached the pre-disturbance Babg within 28 years. The forest exhibited a higher resistance and a slower recovery rate in the more advanced recovery phases, reaching the pre-disturbance Babg within 60-80 years. The recovery was enhanced by higher levels of alpha and beta diversity. Under elevated air temperature, the bark beetle outbreak triggered by windthrow delayed the recovery. However, the positive effect of increased temperature on forest productivity caused the recovery rate to be higher under the warming scenario than under the reference climate. We conclude that resilience is not a static property, but its magnitude and drivers vary in time, depending on vegetation feedbacks, interactions between disturbances, and climate. Understanding these mechanisms is an essential step towards the operationalization of resilience-oriented stewardship.


Assuntos
Mudança Climática , Besouros , Florestas , Animais , Biomassa , Besouros/crescimento & desenvolvimento , Europa (Continente) , Vento
12.
J Chem Ecol ; 47(10-11): 889-906, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34415498

RESUMO

How climate change will modify belowground tritrophic interactions is poorly understood, despite their importance for agricultural productivity. Here, we manipulated the three major abiotic factors associated with climate change (atmospheric CO2, temperature, and soil moisture) and investigated their individual and joint effects on the interaction between maize, the banded cucumber beetle (Diabrotica balteata), and the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora. Changes in individual abiotic parameters had a strong influence on plant biomass, leaf wilting, sugar concentrations, protein levels, and benzoxazinoid contents. Yet, when combined to simulate a predicted climate scenario (Representative Concentration Pathway 8.5, RCP 8.5), their effects mostly counter-balanced each other. Only the sharp negative impact of drought on leaf wilting was not fully compensated. In both current and predicted scenarios, root damage resulted in increased leaf wilting, reduced root biomass, and reconfigured the plant sugar metabolism. Single climatic variables modulated the herbivore performance and survival in an additive manner, although slight interactions were also observed. Increased temperature and CO2 levels both enhanced the performance of the insect, but elevated temperature also decreased its survival. Elevated temperatures and CO2 further directly impeded the EPN infectivity potential, while lower moisture levels improved it through plant- and/or herbivore-mediated changes. In the RCP 8.5 scenario, temperature and CO2 showed interactive effects on EPN infectivity, which was overall decreased by 40%. We conclude that root pest problems may worsen with climate change due to increased herbivore performance and reduced top-down control by biological control agents.


Assuntos
Mudança Climática , Besouros/fisiologia , Cadeia Alimentar , Strongyloidea/fisiologia , Zea mays/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Zea mays/crescimento & desenvolvimento
13.
J Chem Ecol ; 47(10-11): 822-833, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34415500

RESUMO

Chemical cues play important roles in predator-prey interactions. Semiochemicals can aid predator foraging and alert prey organisms to the presence of predators. Previous work suggests that predator traits differentially influence prey behavior, however, empirical data on how prey organisms respond to chemical cues from predator species with different hunting strategies, and how foraging predators react to cues from potential competitors, is lacking. Furthermore, most research in this area has focused on aquatic and aboveground terrestrial systems, while interactions among belowground, soiling-dwelling organisms have received relatively little attention. Here, we assessed how chemical cues from three species of entomopathogenic nematodes (EPNs), each with a different foraging strategy, influenced herbivore (cucumber beetle) and natural enemy (EPN) foraging behavior. We predicted these cues could serve as chemical indicators of increased predation risk, prey availability, or competition. Our findings revealed that foraging cucumber beetle larvae avoided chemical cues from Heterorhabditis bacteriophora (active-foraging cruiser EPNs), but not Steinernema carpocapsae (ambusher EPNs) or Steinernema riobrave (intermediate-foraging EPNs). In contrast, foraging H. bacteriophora EPNs were attracted to cues produced by the two Steinernema species but not conspecific cues. Notably, the three EPN species produced distinct blends of olfactory cues, with only a few semi-conserved compounds across species. These results indicate that a belowground insect herbivore responds differently to chemical cues from different EPN species, with some EPN species avoiding prey detection. Moreover, the active-hunting EPNs were attracted to heterospecific cues, suggesting these cues indicate a greater probability of available prey, rather than strong interspecific competition.


Assuntos
Besouros/fisiologia , Cadeia Alimentar , Feromônios/fisiologia , Comportamento Predatório , Rabditídios/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Rabditídios/química , Especificidade da Espécie
14.
J Med Entomol ; 58(6): 2124-2129, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34426839

RESUMO

This study examined the effects of various diets on the development time and survival of the carrion beetle Thanatophilus rugosus (Fabricius, 1775). We attempted to find the best diet for rearing the species in laboratory conditions for entomological research and forensic purposes, and to further understand its feeding habits. The larval stages were monitored while feeding on three types of meat under a constant temperature. We discovered that the shortest development time in total was achieved in larvae fed with pork liver, followed closely by pork muscle. The longest development and lowest survival rates were observed when introducing a chicken diet. We were also able to identify specific stages during which the diet significantly affected the development.


Assuntos
Besouros/crescimento & desenvolvimento , Animais , Dieta , Entomologia , Entomologia Forense , Larva/crescimento & desenvolvimento
15.
World J Microbiol Biotechnol ; 37(9): 156, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34406525

RESUMO

The control of root-feeding wireworms has become more challenging as synthetic soil insecticides have been progressively phased out due to environmental risk concerns. Innovative microbial control alternatives such as the so-called attract-and-kill strategy depend on the rapid and successful development of dried encapsulated microorganisms, which is initiated by rehydration. Casein is a functional additive that is already used in food or pharmaceutical industry due to its water binding capacity. Cross-linked forms such as formalin-casein (FC), exhibit altered network structures. To determine whether FC influences the rehydration of alginate beads in order to increase the efficacy of an attract-and-kill formulation for wireworm pest control, we incorporated either casein or FC in different alginate/starch formulations. We investigated the porous properties of alginate/starch beads and subsequently evaluated the activities of the encapsulated entomopathogenic fungus Metarhizium brunneum and the CO2 producing yeast Saccharomyces cerevisiae. Adding caseins altered the porous structure of beads. FC decreased the bead density from (1.0197 ± 0.0008) g/mL to (1.0144 ± 0.0008) g/mL and the pore diameter by 31%. In contrast to casein, FC enhanced the water absorbency of alginate/starch beads by 40%. Furthermore, incorporating FC quadrupled the spore density on beads containing M. brunneum and S. cerevisiae, and simultaneous venting increased the spore density even by a factor of 18. Moreover, FC increased the total CO2 produced by M. brunneum and S. cerevisiae by 29%. Thus, our findings suggest that rehydration is enhanced by larger capillaries, resulting in an increased water absorption capacity. Our data further suggest that gas exchange is improved by FC. Therefore, our results indicate that FC enhances the fungal activity of both fungi M. brunneum and S. cerevisiae, presumably leading to an enhanced attract-and-kill efficacy for pest control.


Assuntos
Caseínas/química , Composição de Medicamentos/métodos , Formaldeído/química , Metarhizium/química , Saccharomyces cerevisiae/química , Água/química , Adsorção , Alginatos/química , Animais , Besouros/crescimento & desenvolvimento , Besouros/microbiologia , Composição de Medicamentos/instrumentação , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metarhizium/fisiologia , Controle Biológico de Vetores , Porosidade , Saccharomyces cerevisiae/fisiologia
16.
PLoS One ; 16(7): e0255029, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34297754

RESUMO

Entomopathogenic fungi are regarded as effective biocontrol agents in pest management. Different fungi isolates exhibit varying degree of pathogenicity against red palm weevil [Rhynchophorus ferrugineus (Olivier)]. The pathogenicity of four native isolate from Saudi Arabia (three Beauveria bassiana named as BbSA-1, BbSA-2, BbSA-3 and one Metarhizium anisopliae regarded as MaSA-1) and three exotic isolates from Indonesia (B. bassiana coded as BbIDN-1 and M. anisopliae named as MaIDN-1 and MaIDN-2) was evaluated against red palm weevil under laboratory conditions. The isolates were applied to eggs (1 day old), larvae (3 and 35 days old), pupae (5 days old) and adults (10 days old). The average mortality rate of eggs and hatched larvae was 100% in all of the isolates except BbSA-2 and BbIDN-1, where mortality was 93.3 and 90%, respectively. The lowest mortality rate (73.3%) was recorded for BbSA-3 against 3-days-old larvae; however, all other isolates caused >80% larval mortality. Meanwhile, 93.3% mortality of 35-day-old larvae was noted for MaSA-1 isolate. The highest pupa mortality (80%) was observed for MaSA-1, while remaining isolates caused >60% mortality. The isolates BbSA-1 and MaSA-1 caused 61 and 74.3% mortality in adults, respectively. The tested fungi isolates exhibited high virulence against all life stages of red palm weevil. Local isolates had higher pathogenicity than exotic isolates. The findings of the current study suggest that entomopathogenic fungi could be used as biological control agents for the management of red palm weevil. However, field studies are needed to reach the sound conclusions and practical applications.


Assuntos
Ascomicetos/patogenicidade , Besouros/microbiologia , Controle Biológico de Vetores/métodos , Animais , Besouros/crescimento & desenvolvimento , Larva/microbiologia , Pupa/microbiologia
17.
Sci Rep ; 11(1): 14030, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234157

RESUMO

Because it is important to develop new sustainable sources of edible protein, insects have been recommended as a new protein source. This study applied Life Cycle Assessment (LCA) to investigate the environmental impact of small-scale edible insect production unit in South Korea. IMPACT 2002 + was applied as the baseline impact assessment (IA) methodology. The CML-IA baseline, EDIP 2003, EDP 2013, ILCD 2011 Midpoint, and ReCiPe midpoint IA methodologies were also used for LCIA methodology sensitivity analysis. The protein, fat contents, and fatty acid profile of the investigated insect (Protaetia brevitarsis seulensis larvae) were analyzed to determine its potential food application. The results revealed that the studied edible insect production system has beneficial environmental effects on various impact categories (ICs), i.e., land occupation, mineral extraction, aquatic and terrestrial ecotoxicity, due to utilization of bio-waste to feed insects. This food production system can mitigate the negative environmental effects of those ICs, but has negative environmental impact on some other ICs such as global warming potential. By managing the consumption of various inputs, edible insects can become an environmentally efficient food production system for human nutrition.


Assuntos
Proteínas Animais da Dieta , Besouros/crescimento & desenvolvimento , Gorduras na Dieta , Insetos Comestíveis/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Animais , Meio Ambiente , Valor Nutritivo , República da Coreia
18.
PLoS One ; 16(7): e0253885, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234367

RESUMO

Multigenerational effects (often called maternal effects) are components of the offspring phenotype that result from the parental phenotype and the parental environment as opposed to heritable genetic effects. Multigenerational effects are widespread in nature and are often studied because of their potentially important effects on offspring traits. Although multigenerational effects are commonly observed, few studies have addressed whether they affect offspring fitness. In this study we assess the effect of potential multigenerational effects of parental body size and natal carcass size on lifetime fitness in the burying beetle, Nicrophorus marginatus (Coleoptera; Silphidae). Lifespan, total number of offspring, and number of offspring in the first reproductive bout were not significantly related to parental body size or natal carcass size. However, current carcass size used for reproduction was a significant predictor for lifetime number of offspring and number of offspring in the first brood. We find no evidence that multigenerational effects from larger parents or larger natal carcasses contribute to increased fitness of offspring.


Assuntos
Tamanho Corporal/genética , Besouros/genética , Herança Materna , Animais , Besouros/crescimento & desenvolvimento , Feminino , Aptidão Genética , Larva/genética , Masculino
19.
J Insect Physiol ; 132: 104272, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34186071

RESUMO

Alterations in cell number and size are apparently associated with the body mass differences between species and sexes, but we rarely know which of the two mechanisms underlies the observed variance in body mass. We used phylogenetically informed comparisons of males and females of 19 Carabidae beetle species to compare body mass, resting metabolic rate, and cell size in the ommatidia and Malpighian tubules. We found that the larger species or larger sex (males or females, depending on the species) consistently possessed larger cells in the two tissues, indicating organism-wide coordination of cell size changes in different tissues and the contribution of these changes to the origin of evolutionary and sex differences in body mass. The species or sex with larger cells also exhibited lower mass-specific metabolic rates, and the interspecific mass scaling of metabolism was negatively allometric, indicating that large beetles with larger cells spent relatively less energy on maintenance than small beetles. These outcomes also support existing hypotheses about the fitness consequences of cell size changes, postulating that the low surface-to-volume ratio of large cells helps decrease the energetic demand of maintaining ionic gradients across cell membranes. Analyses with and without phylogenetic information yielded similar results, indicating that the observed patterns were not biased by shared ancestry. Overall, we suggest that natural selection does not operate on each trait independently and that the linkages between concerted cell size changes in different tissues, body mass and metabolic rate should thus be viewed as outcomes of correlational selection.


Assuntos
Metabolismo Basal , Evolução Biológica , Tamanho Corporal , Tamanho Celular , Besouros , Animais , Besouros/crescimento & desenvolvimento , Besouros/metabolismo , Besouros/fisiologia , Caracteres Sexuais
20.
Zootaxa ; 4970(2): 303312, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34186894

RESUMO

Sap beetle, Epuraea ocularis Fairmaire usually lays eggs and breeds on fermenting overripe fruits, and larvae pass through different instars before pupating on soil. In laboratory condition, mating pairs of adults copulated and females laid eggs in clusters; larva hatched out in 1 to 2 days, passed through four instars; mature larva migrated to soil for pupation. Larval development took about 12 to 17 days; and adult hatched out of pupa in about 4 to 5 days. Detailed morphology of egg, larva and pupa is presented herein, and significance of larva in taxonomy of beetles has been indicated.


Assuntos
Besouros/classificação , Animais , Besouros/crescimento & desenvolvimento , Feminino , Índia , Larva , Pupa , Solo
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