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1.
Sci Rep ; 14(1): 15259, 2024 07 03.
Article in English | MEDLINE | ID: mdl-38956259

ABSTRACT

Greenhouse whitefly (Trialeurodes vaporariorum) is a major global pest, causing direct damage to plants and transmitting viral plant diseases. Management of T. vaporariorum is problematic because of widespread pesticide resistance, and many greenhouse growers rely on biological control agents to regulate T. vaporariorum populations. However, these are often slow and vary in efficacy, leading to subsequent application of chemical insecticides when pest populations exceed threshold levels. Combining chemical and biological pesticides has great potential but can result in different outcomes, from positive to negative interactions. In this study, we evaluated co-applications of the entomopathogenic fungi (EPF) Beauveria bassiana and Cordyceps farinosa and the chemical insecticide spiromesifen in laboratory bioassays. Complex interactions between the EPFs and insecticide were described using an ecotoxicological mixtures model, the MixTox analysis. Depending on the EPF and chemical concentrations applied, mixtures resulted in additivity, synergism, or antagonism in terms of total whitefly mortality. Combinations of B. bassiana and spiromesifen, compared to single treatments, increased the rate of kill by 5 days. Results indicate the potential for combined applications of EPF and spiromesifen as an effective integrated pest management strategy and demonstrate the applicability of the MixTox model to describe complex mixture interactions.


Subject(s)
Beauveria , Hemiptera , Insecticides , Pest Control, Biological , Animals , Hemiptera/drug effects , Hemiptera/microbiology , Insecticides/pharmacology , Beauveria/physiology , Pest Control, Biological/methods , Cordyceps , Spiro Compounds/pharmacology
2.
Sci Total Environ ; 947: 174521, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38972414

ABSTRACT

Chlorination is the most widely used disinfection technology due to its simplicity and continuous disinfection ability. However, the drawbacks of disinfection by-products and chlorine-resistant bacteria have gained increasing attention. Nowadays, ferrate (Fe(VI)) is a multifunctional and environmentally friendly agent which has great potential in wastewater reclamation and reuse. This study investigated synergistic Fe(VI) and chlorine technology for reclaimed water disinfection in terms of microbial control and chlorine decay mitigation. Specifically, synergistic disinfection significantly improved the inactivation efficiency on total coliform, Escherichia coli and heterotrophic bacteria compared to sole chlorination. Synergistic disinfection also exhibited superior performance on controlling the relative abundance of chlorine-resistant bacteria and pathogenic bacteria. In addition, the decay rate of residual chlorine was relatively lower after Fe(VI) pretreatment, which was beneficial for microbial control during the reclaimed water distribution process. Technical and economic analyses revealed that synergistic Fe(VI) and chlorine disinfection was suitable and feasible. Results of this study are believed to provide useful information and alternative options on the optimization of reclaimed water disinfection.

3.
J Invertebr Pathol ; 205: 108121, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38705355

ABSTRACT

The oak processionary moth (OPM) Thaumetopoea processionea is a pest of oak trees and poses health risks to humans due to the urticating setae of later instar larvae. For this reason, it is difficult to rear OPM under laboratory conditions, carry out bioassays or examine larvae for pathogens. Biological control targets the early larval instars and is based primarily on commercial preparations of Bacillus thuringiensis ssp. kurstaki (Btk). To test the entomopathogenic potential of other spore-forming bacteria, a user-friendly bioassay system was developed that (i) applies bacterial spore suspensions by oak bud dipping, (ii) targets first instar larvae through feeding exposure and (iii) takes into account their group-feeding behavior. A negligible mortality in the untreated control proved the functionality of the newly established bioassay system. Whereas the commercial Btk HD-1 strain was used as a bioassay standard and confirmed as being highly efficient, a Bacillus wiedmannii strain was ineffective in killing OPM larvae. Larvae, which died during the infection experiment, were further subjected to Nanopore sequencing for a metagenomic approach for entomopathogen detection. It further corroborated that B.wiedmannii was not able to infect and establish in OPM, but identified potential insect pathogenic species from the genera Serratia and Pseudomonas.


Subject(s)
Biological Assay , Larva , Moths , Pest Control, Biological , Animals , Moths/microbiology , Biological Assay/methods , Pest Control, Biological/methods , Larva/microbiology , Metagenome , Quercus/microbiology , Bacillus thuringiensis/genetics
4.
Biotechnol Prog ; 40(3): e3431, 2024.
Article in English | MEDLINE | ID: mdl-38450889

ABSTRACT

The move to integrated continuous bioprocessing (ICB), while providing a means for process intensification, can put added strain on process analytics when conventional methods are used. For instance, traditional microbial methods provide minimal value to ICB processes given that the time required for data to become available is much longer than a typical full cycle of the manufacturing process. Although rapid microbial detection has been in discussion for over 30 years, it is still not routinely deployed in commercial biopharmaceutical manufacturing. One contributing factor is the ability to integrate this technology into a process control strategy and existing quality systems. An understanding of the capability of microbial detection technology available today can be leveraged to implement a control strategy for bioburden monitoring in real time for process intermediates. One key tenet of this proposed control strategy is the use of a "two-tiered approach" wherein a fast (but possibly less sensitive) test is used to monitor the process and trigger further action for a second, longer duration test which is used to confirm and quantify the presence of bioburden and identify the organism. This approach, presented here alongside several case studies for microbial monitoring, can have broader application for other process analytical technologies where fit for purpose methods could be employed to establish process control alongside real time continuous processes.


Subject(s)
Quality Control , Bioreactors/microbiology , Biotechnology/methods , Bacteria/isolation & purification
5.
J Invertebr Pathol ; 204: 108079, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38447862

ABSTRACT

Studies on community composition and population structure of entomopathogenic fungi are imperative to link ecosystem functions to conservation biological control. We studied the diversity and abundance of Metarhizium spp. from soil of conventionally and organically farmed strawberry crops and from the adjacent field margins in two different climatic zones: Brazil (tropical) and Denmark (temperate), using the same isolating methods. In Brazilian strawberry soil, Metarhizium robertsii (n = 129 isolates) was the most abundant species, followed by M. humberi (n = 16); M. anisopliae (n = 6); one new taxonomically unassigned lineage Metarhizium sp. indet. 5 (n = 4); M. pingshaense (n = 1) and M. brunneum (n = 1). In Denmark, species composition was very different, with M. brunneum (n = 33) being isolated most commonly, followed by M. flavoviride (n = 6) and M. pemphigi (n = 5), described for the first time in Denmark. In total, 17 haplotypes were determined based on MzFG543igs sequences, four representing Danish isolates and 13 representing Brazilian isolates. No overall difference between the two climatic regimes was detected regarding the abundance of Metarhizium spp. in the soil in strawberry fields and the field margins. However, we found a higher Shannon's diversity index in organically managed soils, confirming a more diverse Metarhizium community than in soils of conventionally managed agroecosystems in both countries. These findings contribute to the knowledge of the indigenous diversity of Metarhizium in agricultural field margins with the potential to contribute to pest regulation in strawberry cropping systems.


Subject(s)
Fragaria , Metarhizium , Soil Microbiology , Fragaria/microbiology , Brazil , Denmark , Pest Control, Biological
6.
Compr Rev Food Sci Food Saf ; 23(1): e13290, 2024 01.
Article in English | MEDLINE | ID: mdl-38284591

ABSTRACT

Aquatic foods are nutritious, enjoyable, and highly favored by consumers. In recent years, young consumers have shown a preference for prefabricated food due to its convenience, nutritional value, safety, and increasing market share. However, aquatic foods are prone to microbial spoilage due to their high moisture content, protein content, and unsaturated fatty acids. Furthermore, traditional processing methods of aquatic foods can lead to issues such as protein denaturation, lipid peroxidation, and other food safety and nutritional health problems. Therefore, there is a growing interest in exploring new technologies that can achieve a balance between antimicrobial efficiency and food quality. This review examines the mechanisms of cold plasma, high-pressure processing, photodynamic inactivation, pulsed electric field treatment, and ultraviolet irradiation. It also summarizes the research progress in nonthermal physical field technologies and their application combined with other technologies in prefabricated aquatic food. Additionally, the review discusses the current trends and developments in the field of prefabricated aquatic foods. The aim of this paper is to provide a theoretical basis for the development of new technologies and their implementation in the industrial production of prefabricated aquatic food.


Subject(s)
Food Handling , Food Preservation , Food Quality , Nutritive Value , Food Safety
7.
Pest Manag Sci ; 80(3): 1053-1064, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37837273

ABSTRACT

BACKGROUND: The red palm weevil (RPW), Rhynchophorus ferrugineus, is one of the gravest threats to palm trees. The challenge in monitoring RPW primarily arises from the inconspicuous presence of larvae within the stem, which is often devoid of noticeable symptoms. This study looks at the use of seismic sensors in RPW management in commercial date palm plantations. It explores whether the data garnered from the sensor domain, and its translation into the health status of date palms, can reliably inform precise decision-making. RESULTS: Sensor and damage index values, as gauged by the Agrint IoTree seismic sensor, vividly mirrored RPW colonization activity. They also accurately portrayed the impact of three distinct insecticides: imidacloprid, phosphine, and entomopathogenic nematodes. The seismic values and damage index of healthy untreated palms strongly supported the decision to pursue tree recovery. Furthermore, this facilitated the computation of recovery pace discrepancies across the tested treatments, measured as the number of days required for tree restoration. CONCLUSIONS: Our findings underscore the practicality of employing seismic sensors, as exemplified by the IoTree system and its network services, to both monitor and assess palm tree health. Furthermore, it validates their efficacy in evaluating the efficiency of management strategies adopted against RPW, all grounded in a wealth of sensor-derived data. © 2023 Society of Chemical Industry.


Subject(s)
Insecticides , Phoeniceae , Weevils , Animals , Larva
8.
Pest Manag Sci ; 80(1): 81-86, 2024 Jan.
Article in English | MEDLINE | ID: mdl-36765405

ABSTRACT

Biopesticides (commonly called Biocontrol or more recently bioprotection) have been experiencing double digit growth and now comprise about 10% of the global pesticide market driven by increased return on investment, restrictions on chemical pesticides, and pesticide resistance and residue management. However, despite the large need for new herbicides due to widespread and increasing resistance to herbicides with almost most of the chemical modes of action, bioherbicides are an insignificant percentage of the total. The technical difficulty in finding bioherbicides that can compete with the spectrum and price of chemical herbicides has left agriculture with a paucity of new bioherbicides. Billions of dollars of investment capital are being invested in new, innovative startups, but only a small number focus on bioherbicide discovery and development, due to a perception of higher risk than plant biotech, biostimulants, bionutrients and other categories of biopesticides. However, the exciting new technologies that these startups are developing such as RNAi, sterile pollen, and systemic metabolites have potential to impact the market in 10 years or less. © 2023 Society of Chemical Industry.


Subject(s)
Herbicides , Pesticides , Biological Control Agents/pharmacology , Pesticides/pharmacology , Pesticides/chemistry , Herbicides/pharmacology , Agriculture
9.
Insects ; 14(12)2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38132592

ABSTRACT

The red palm weevil (RPW) Rhynchophorus ferrugineus is a highly destructive invasive pest for palms whose management is mainly by application of synthetic pesticides. As a key pest of date palm plantations, it is necessary to integrate environmentally safe measures for its management. Entomopathogenic fungi (EPF) have been primarily studied as a preventative control measure due to the horizontal transfer of conidia within the RPW population. We previously demonstrated the horizontal transmission of fungal conidia from an egg-laying surface to the female weevil and then to the eggs and larvae. Based on that strategy, this study aimed to evaluate the virulence of commercial EPF products and laboratory EPF preparations to RPW females and their progeny, and their ability to protect palms against infestation. As such, it serves as a screening platform for field experiments. Mortality rates of females and eggs depended on the applied treatment formulation and fungal strain. Velifer®, a Beauveria bassiana product, and Metarhizium brunneum (Mb7) resulted in 60-88% female mortality. Mb7-as a conidial suspension or powder-resulted in 18-21% egg-hatching rates, approximately 3 times less than in the non-treated control. Treating palms with Mb7 suspension or dry formulation significantly inhibits infestation signs and results in protection. These results lay the foundation for investigating the protective rate of EPF products against RPW in date plantations.

10.
Microorganisms ; 11(6)2023 Jun 16.
Article in English | MEDLINE | ID: mdl-37375101

ABSTRACT

The discovery of biomolecules has been the subject of extensive research for several years due to their potential to combat harmful pathogens that can lead to environmental contamination and infections in both humans and animals. This study aimed to identify the chemical profile of endophytic fungi, namely Neofusicoccum parvum and Buergenerula spartinae, which were isolated from Avecinnia schaueriana and Laguncularia racemosa. We identified several HPLC-MS compounds, including Ethylidene-3,39-biplumbagin, Pestauvicolactone A, Phenylalanine, 2-Isopropylmalic acid, Fusaproliferin, Sespendole, Ansellone, Calanone derivative, Terpestacin, and others. Solid-state fermentation was conducted for 14-21 days, and methanol and dichloromethane extraction were performed to obtain a crude extract. The results of our cytotoxicity assay revealed a CC50 value > 500 µg/mL, while the virucide, Trypanosoma, leishmania, and yeast assay demonstrated no inhibition. Nevertheless, the bacteriostatic assay showed a 98% reduction in Listeria monocytogenes and Escherichia coli. Our findings suggest that these endophytic fungi species with distinct chemical profiles represent a promising niche for further exploring new biomolecules.

11.
Foods ; 12(5)2023 Feb 26.
Article in English | MEDLINE | ID: mdl-36900504

ABSTRACT

The dairy field has considerable economic relevance in the agri-food system, but also has the need to develop new 'green' supply chain actions to ensure that sustainable products are in line with consumer requirements. In recent years, the dairy farming industry has generally improved in terms of equipment and product performance, but innovation must be linked to traditional product specifications. During cheese ripening, the storage areas and the direct contact of the cheese with the wood must be carefully managed because the proliferation of contaminating microorganisms, parasites, and insects increases significantly and product quality quickly declines, notably from a sensory level. The use of ozone (as gas or as ozonated water) can be effective for sanitizing air, water, and surfaces in contact with food, and its use can also be extended to the treatment of waste and process water. Ozone is easily generated and is eco-sustainable as it tends to disappear in a short time, leaving no residues of ozone. However, its oxidation potential can lead to the peroxidation of cheese polyunsaturated fatty acids. In this review we intend to investigate the use of ozone in the dairy sector, selecting the studies that have been most relevant over the last years.

12.
Microb Ecol ; 86(1): 647-657, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36002667

ABSTRACT

Entomopathogenic fungi may play a crucial role in the regulation of caterpillar populations in soybean crops, either through natural occurrences or applied as mycopesticides. In the present work, we reported the naturally occurring entomopathogenic fungus Pandora gammae attacking the caterpillar Chrysodeixis includens, with infection rates in field trials ran in two consecutive years in the 10-35% range. As many chemicals are potentially harmful to entomopathogenic fungi, this work aimed to investigate the potential impact of two chemical fungicides (azoxystrobin + benzovindiflupyr and trifloxistrobina + prothioconazole) used to control soybean rust (Phakopsora pachyrhizi) on the natural occurrence of P. gammae and Metarhizium rileyi, as well as the efficacy of the latter fungus applied as different formulations against the soybean caterpillars Anticarsia gemmatalis and C. includens. Under laboratory conditions, fungicides used at field-recommended rates had a considerable negative impact on the germinability of M. riley on the medium surface, and all tested formulations did not protect conidia from damage by these chemicals. This harmful effect also impacted host infectivity, as the larval mortality owing to this fungus was reduced by 30-40% compared to that of the fungicide-free treatments. In field trials conducted in two subsequent years, unformulated and formulated M. rileyi conidia applied to soybean plants produced primary infection sites in caterpillar populations after a single spray. Spraying unformulated or formulated M. rileyi conidia following fungicide application on plants did not affect host infection rates over time. Moreover, the use of M. rileyi-based formulations or chemical fungicide did not interfere with the natural infection rates by P. gammae on its host, C. includens. Although a higher degree of exposure to non-selective fungicides can negatively affect fungal entomopathogens, a single foliar application of fungicides may be harmless to both M. rileyi and P. gammae in soybean fields. Additionally, this work showed that naturally occurring wasps and tachnids also play an important role in the regulation of A. gemmatalis and, notably, C. includens, with parasitism rates above 40-50% in some cases.


Subject(s)
Fungicides, Industrial , Metarhizium , Moths , Animals , Glycine max , Larva/microbiology , Crops, Agricultural , Fungicides, Industrial/pharmacology
13.
Int J Food Microbiol ; 384: 109984, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36341755

ABSTRACT

The current study aimed to incorporate Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus casei, and Lacticaseibacillus rhamnosus (~10 log CFU/ml) into gelatin­sodium alginate nanofibers via electrospinning process in order to investigate the influence of fabricated mats on the growth of food-related pathogenic bacteria and shelf-life extension of refrigerated silver carp fillets in a two-week period. The strain-loaded nanofibers exhibited lower water vapor permeability, swelling index, moisture content, and tensile strength than the straight nanofibers (P < 0.05). The survival order of probiotics in nanofibers stored at 4, 25, and 37 °C for 14 days are as follows: L. acidophilus (8.15-9.35 log CFU/g) > L. reuteri (7.42-9.24 log CFU/g) > L. casei (7.41-9.13 log CFU/g) > L. rhamnosus (7.37-8.92 log CFU/g). The probiotic mats significantly delayed the growth of Vibrio parahaemolyticus, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in silver carp fillets in comparison with the unpackaged sample (P < 0.05). Moreover, the designated nanofibers improved the bacterial, chemical, and sensory properties of treated samples in comparison with the unpackaged samples throughout the study period. Our findings indicate that gelatin­sodium alginate nanofibers are a suitable platform for the protection of living probiotics and present an alternative procedure for retarding the growth of food-borne pathogens and extending the shelf-life of fresh carp fillets under refrigerated storage conditions.


Subject(s)
Carps , Listeria monocytogenes , Nanofibers , Probiotics , Animals , Gelatin/pharmacology , Alginates/pharmacology , Colony Count, Microbial
14.
J Microorg Control ; 28(4): 165-175, 2023.
Article in English | MEDLINE | ID: mdl-38233168

ABSTRACT

Hypochlorous acid (HOCl) is an active species in the chlorination process. Hypochlorite salts that release hypochlorite ion (OCl-) have been used for more than 200 years as disinfecting, cleaning, deodorizing, and decolorizing agents in various technological fields. In the food industry, sodium hypochlorite is the most widely used among chlorine compounds. The antimicrobial activity of a dilute hypochlorite solution is attributed largely to HOCl because of its cell membrane permeability. OCl- exhibits an excellent cleaning action for organic soils on solid surfaces. HOCl has been used as an aqueous solution, and its objects to be treated are things. In hypochlorite solution, HOCl is volatile and easily volatilized by stirring, bubbling, atomizing, or forced-air vaporization. On the other hand, OCl- is non-volatile and stays in the solution. Recently, the scope of objects to be treated with hypochlorite solution has been expanded to indoor spaces, and the use of gaseous hypochlorous acid (HOCl(g) ) has been studied intensively. This review describes the mechanisms of actions of hypochlorous acid as liquid-based and gaseous disinfectants and provides the evidence for the safety and effectiveness of HOCl(g) for controlling microorganisms in indoor spaces.


Subject(s)
Disinfectants , Hypochlorous Acid , Hypochlorous Acid/pharmacology , Gases , Sodium Hypochlorite/pharmacology , Disinfectants/pharmacology , Water
15.
Front Insect Sci ; 3: 1195254, 2023.
Article in English | MEDLINE | ID: mdl-38469514

ABSTRACT

The term "microbial control" has been used to describe the use of microbial pathogens (bacteria, viruses, or fungi) or entomopathogenic nematodes (EPNs) to control various insect pest populations. EPNs are among the best biocontrol agents, and major developments in their use have occurred in recent decades, with many surveys having been conducted all over the world to identify EPNs that may have potential in the management of insect pests. For nematodes, the term "entomopathogenic" means "causing disease to insects" and is mainly used in reference to the bacterial symbionts of Steinernema and Heterorhabditis (Xenorhabdus and Photorhabdus, respectively), which cause EPN infectivity. A compendium of our multiannual experiences on EPN surveys and on their collection, identification, characterization, and use in agro-forestry ecosystems is presented here to testify and demonstrate once again that biological control with EPNs is possible and offers many advantages over chemicals, such as end-user safety, minimal damage to natural enemies, and lack of environmental pollution, which are essential conditions for an advanced IPM strategy.

16.
Food Res Int ; 162(Pt B): 112070, 2022 12.
Article in English | MEDLINE | ID: mdl-36461325

ABSTRACT

Deoxynivalenol (DON) is prevalent in wheat and threatens the health of humans and animals. It has been certificated that plasma activated water (PAW) can effectively degrade DON in wheat. However, the application of PAW used in the production of wheat flours was not reported nowadays. Thus, PAW was used to replace pure water in the traditional tempering process to eliminate DON in wheat, and DON degradation effect of PAW was compared with H2O2 and O3. The DON degradation rate was 58.78 % by tempering for 24 h with PAW prepared at 50 kV for 10 min. The H2O2 and O3 were found to be critical contributors in PAW for DON degradation. Afterwards, effects of PAW on microorganism inactivation and wheat qualities were studied. After tempering with PAW, the bacterial and fungal counts, the number of surviving Fusarium graminearum in wheat were decreased significantly. Moreover, no negative effects were observed except a slight decrease in vitamin E content. Therefore, tempering with PAW can be a promising strategy to control DON pollutant in wheat.


Subject(s)
Hydrogen Peroxide , Triticum , Animals , Humans , Plasma , Water
17.
J Invertebr Pathol ; 194: 107824, 2022 10.
Article in English | MEDLINE | ID: mdl-36030047

ABSTRACT

Fungal entomopathogens can greatly reduce the fitness of their hosts, and it is therefore expected that susceptible insects will be selected to avoid exposure to pathogens. Metarhizium brunneum is a fungal pathogen that can infect Agriotes obscurus, which in its larval form is a destructive agricultural pest and is repelled by the presence of M. brunneum conidia. Due to the subterranean nature of larval A. obscurus, recent research has focused on targeting adult A. obscurus with M. brunneum. No-choice and choice behavioural assays were conducted to determine if male adult A. obscurus avoid M. brunneum mycosed cadavers, or conidia applied to either food or soil. To further investigate the response of A. obscurus beetles to conspecific cadavers, the movement and behaviour of beetles placed at the centre of a semi-circular arrangement of mycosed or control cadavers was examined using motion tracking software. We found little evidence to suggest that A. obscurus male beetles avoid M. brunneum conidia or mycosed conspecific cadavers or alter their behaviour in their presence.


Subject(s)
Coleoptera , Metarhizium , Animals , Cadaver , Coleoptera/microbiology , Larva/microbiology , Male , Metarhizium/physiology , Pest Control, Biological , Soil , Spores, Fungal
18.
Rev Sci Tech ; 41(1): 107-116, 2022 May.
Article in English | MEDLINE | ID: mdl-35925630

ABSTRACT

Honeybees, bumblebees and other insects have been used commercially for pollination for many years, and microbial biocontrol agents have also been widely used in pest control. Pollinators and formulations of microbial pest-control agents are routinely transported internationally on a large scale. A novel approach has been developed to use bees as vectors of microbial agents by inoculating the surface of the pollinators using dispensers in modified hives. This innovation extends the market for these products and results in better yields. A successful entomovector system requires selecting the vector pollinator most appropriate for the crop and location, based on various criteria, in combination with a registered microbial agent. Currently, pollinators and microbial agents are packed separately and combined at the point of use. Local sourcing of the pollinator in the system reduces the need for long-distance shipping of these live insects and may improve efficiency due to local adaptation; however, it will delay use and benefits of the system until research at each site/country catches up with the work already conducted in a few countries. In the meantime, clear guidance for innovative systems employing live insects could support the promising increase in food production.


Depuis plusieurs années, les abeilles mellifères, les bourdons et d'autres insectes sont commercialisés à des fins de pollinisation, parallèlement à l'utilisation désormais largement répandue de micro-organismes pour la lutte biologique contre les nuisibles. Les pollinisateurs et diverses formulations d'agents microbiens destinés à la lutte contre les nuisibles font régulièrement l'objet de transports internationaux à grande échelle. Une approche innovante mise au point récemment consiste à utiliser les abeilles en tant que vecteurs d'agents microbiens, en inoculant ces derniers sur la surface du pollinisateur par le biais de diffuseurs disposés dans les ruches modifiées à cette fin. Cette innovation amplifie le marché de ces produits et se traduit par un meilleur rendement. La réussite d'un système d'entomovection passe par la sélection judicieuse du vecteur pollinisateur en fonction des cultures à protéger et du site, sur la base de plusieurs critères, et par son utilisation en association avec un agent antimicrobien autorisé. À l'heure actuelle, les pollinisateurs et les agents microbiens sont conditionnés séparément et leur assemblage est effectué sur le site même d'utilisation. L'approvisionnement local en pollinisateurs au sein du système réduit la nécessité de transporter ces insectes vivants sur de longues distances et pourrait améliorer l'efficacité du système au moyen d'adaptations locales ; néanmoins, cela retardera la mise en oeuvre du système et l'obtention de résultats bénéfiques, le temps que la recherche conduite dans les sites ou les pays utilisateurs atteigne le niveau des avancées déjà enregistrées dans un petit nombre d'autres pays. En attendant, des directives claires en faveur des systèmes innovants basés sur l'utilisation d'insectes vivants pourraient oeuvrer à l'appui d'une croissance prometteuse de la production alimentaire.


El uso comercial de abejas melíferas, abejorros y otros insectos con fines de polinización tiene ya muchos años. También está muy extendido el empleo de agentes microbianos de control biológico como método de lucha contra las plagas. El transporte internacional y a gran escala de polinizadores y de ciertas formulaciones de plaguicidas microbianos es algo muy habitual. Ahora se ha concebido un novedoso planteamiento en el que se utilizan ápidos como vectores de agentes microbianos. Para ello, se impregna de estos agentes la superficie del insecto polinizador empleando dispensadores en colmenas modificadas. Tal innovación amplía el mercado de estos productos y depara mejores cosechas. Para que un sistema entomovectorial sea eficaz es preciso seleccionar el vector polinizador que mejor encaje con el cultivo y las condiciones locales atendiendo a diversos criterios y combinarlo con un agente microbiano registrado. Actualmente, los polinizadores y los agentes microbianos se embalan por separado y se combinan solo en el punto de aplicación. El aprovisionamiento del polinizador del sistema a partir de fuentes locales hace menos necesarios los envíos a larga distancia de estos insectos vivos y puede ofrecer más eficacia gracias al mayor grado de adaptación del insecto a las condiciones locales. Sin embargo, ello retrasará el uso del sistema y la obtención de los consiguientes beneficios, pues habrá que esperar a que en cada lugar o país se haya llevado el procedimiento tan lejos como se ha hecho hasta ahora en unos pocos países. Mientras tanto, la existencia de claras pautas sobre estos innovadores sistemas en que se emplean insectos vivos podría traducirse en un prometedor aumento de la producción alimentaria.


Subject(s)
Crop Protection , Pollination , Animals , Bees , Insecta
19.
J Invertebr Pathol ; 191: 107767, 2022 06.
Article in English | MEDLINE | ID: mdl-35500673

ABSTRACT

Viruses have been used successfully as biocontrol agents against several insect pests but not ants. Laboratory tests have shown that Solenopsis invicta virus 3 (SINV-3) may be an effective natural control agent against its host, the red imported fire ant (Solenopsis invicta Buren). In this field trial, SINV-3 was released into 12 active S. invicta nests within a 0.088-hectare area in Florida and the impact on the ants monitored. SINV-3 was successfully transmitted, established, and multiplied within treated colonies reaching a maximum mean value of 8.71 × 108 ± 8.26 × 108 SINV-3 genome equivalents/worker ant 77 days after inoculation. SINV-3 was not detected in any of the nests in the control group. A 7-fold decrease in nests was observed in the SINV-3-treated group compared with the untreated control. A correspondingly significant decrease in S. invicta nest size also was observed over the course of the evaluation. Based on the nest rating scale, nest size among those treated with SINV-3 decreased from 3.92 ± 1.24 on day 0 to 1.67 ± 2.06 on day 77, which represents a 57.4% decrease in size. Conversely, the nest rating for the control group increased 9.3%, from 4.42 ± 1.24 on day 0 to 4.83 ± 2.12 on day 77. A follow-up survey of SINV-3-treated and -untreated plots conducted 9 months after initial treatment revealed that fire ant populations rebounded, but at a different rate. A total of 11 and 19 nests were detected in the SINV-3-treated and -untreated areas, respectively. SINV-3 was still detected in the treated area 1.8 years after the initial virus treatment and the virus had spread into the adjacent control plot. Results demonstrate that SINV-3 is an effective natural control agent against the invasive ant, S. invicta; the virus causes no known detrimental ecological impacts, is host specific, and sustained in the environment.


Subject(s)
Ants , RNA Viruses , Animals , DNA Viruses , Florida , RNA Viruses/genetics
20.
Arch Microbiol ; 204(5): 271, 2022 Apr 20.
Article in English | MEDLINE | ID: mdl-35445346

ABSTRACT

Schistosoma mansoni is a heteroxenous parasite, meaning that during its life cycle needs the participation of obligatory intermediate and definitive hosts. The larval development occurs in aquatic molluscs belonging to the Biomphalaria genus, leading to the formation of cercariae, which emerge to infect the final vertebrate host. For this reason, studies for control of the diseases caused by digenetic trematodes often focus on combating the snail hosts. Thus, the objective of this study was to evaluate the susceptibility of Biomphalaria tenagophila embryos to the fungus Pochonia chlamydosporia (isolate Pc-10). The entire experiment was conducted in duplicate, with five replicates for each repetition (five egg masses/replicate), utilizing a total of 100 egg masses, with 20-30 eggs/egg mass. At the end of 15 days, the egg masses were evaluated under a stereomicroscope to analyze the hatching of B. tenagophila embryos in both experimental groups. After days of interaction, the exposure to the fungal hyphae bodies significantly impaired the viability of the B. tenagophila eggs, inhibiting the embryogenesis process by 83.7% in relation to the control group. Transmission and scanning electron microscopic images revealed relevant structural alterations in the egg masses exposed to the hyphae action of the fungus, interfering in the development and hatching of the young snails under analysis. These results indicate the susceptibility of B. tenagophila embryos to the fungus P. chlamydosporia (isolate Pc-10) and suggest the potential of Pc-10 to be used in the control of intermediate host, for its ovicidal capacity and for being an ecologically viable option, but in vivo experiments become necessary.


Subject(s)
Ascomycota , Biomphalaria , Animals , Biomphalaria/parasitology , Host-Parasite Interactions , Hypocreales , Schistosoma mansoni , Snails
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