Biological Control Research Articles

Isolation and characterization of halophilic Bacillus thuringiensis from local Egyptian sites and their potential against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Abstract Background Bacillus thuringiensis (Bt) serves as a peculiar soil microbe that is Gram-positive, rod-shaped, spore-forming, and aerobic facultative. It endures across a range of conditions and has been demonstrated to be an effective biological pest control agent against several insect pests. The main objective of the study is to isolate and recognize Bt bacteria from saline environments in Egyptian soil for biological surveillance uses. Results Isolates three, four, five, ten, eleven, twelve, and thirteen were found to be moderately tolerant, while isolate eight showed highly tolerant, but isolate six was found to be borderline extreme halophile. On the other hand, the other isolates showed extreme halophiles. To find out the presence of crystals, a scanning electron microscope was carried out and the result showed that the crystals ranged from spherical to bi-pyramidal spherical. Molecular analysis was carried out using universal primers to confirm the presence of cry genes. The results showed that 84.6% of the isolates contain cry seven and eight, whereas cry one and four are distributed by 92.3%. Cry two genes were found to be 100 percent in all tested and isolated cultures. Cry genes were present and distribution among isolated was detected using gene-specific primers. cry3Ba1 and cry8B showed the lowest and equal distribution among the isolates, while the cry2Ab2gene frequency distribution was (84.6%) among isolated cultures. Around six cry genes were found to be absent in all isolated cultures. The bioinsecticidal activity and bioassays were carried out to check the potential effect of halophilic Bt isolates against 1st instar larvae of the Fall Armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Mortality was calculated after infecting S. frugiperda with thirteen Bt isolates. The most virulent Bt isolate was isolate 7, followed by isolate 10, with LC50 values of 9.542 × 107 spores/ml and 1.289 × 108 spores/ml, respectively, after 72 h. Morphological traits of the larvae were carried out, to check the effect of Bt isolates as a biological control against the FAW. Conclusion To protect and enhance the sustainability of field crops and vegetables, especially in new high salinity lands, from disease-causing insects such as FAW, it is necessary to identify new strains of Bt from these saline lands. In this field, local isolates of Bt from several regions in Egypt known for their high levels of salinity were documented and showed an effective bioinsecticide on FAW larvae.

Plant Growth Promoting Microorganisms and Emerging Biotechnological Approaches for Sugarcane Disease Management

Sugarcane (Saccharum officinarum L.) is a highly valuable agricultural crop, cultivated globally in tropical and subtropical regions, primarily for its sugar content. Out of the 110 countries that grow sugarcane, India and Brazil together account for half of the world’s total production. Being an annual crop, it is prone to many diseases. The major diseases that can affect the sugarcane are red rot, wilt, sett rot, grassy shoot and pokkah boeng. Among the diseases Colletotrichum falcatum, Fusarium sacchari, Ceratocystis paradoxa, Candidatus Phytoplasma and Fusarium fujikuroi pathogen leads to more yield loss. Traditional disease management strategies, such as chemical treatments, conventional methods and biological control, offer limited protection throughout the crop cycle and raise concerns regarding environmental impact and sustainability. In recent years, plant growth-promoting microorganisms (PGPMs) have emerged as a promising alternative, offering environmentally friendly solutions to enhance plant health and manage diseases. RNAi has been explored to manage various diseases caused by viruses, fungi, and bacteria. By silencing key pathogenicity genes in the causal organisms, sugarcane mosaic virus (SCMV), smut, and leaf scald. The integration of PGPMs with RNAi emerging biotechnological tools and transcriptomics presents a sustainable approach to disease control, potentially reducing the dependency on chemical pesticides and promoting eco-friendly agricultural practices.

Biological control of nosemosis in Apis mellifera L. with Acacia nilotica extract.

Nosemosis is one of the most devastating diseases of Apis mellifera (Honey bees) caused by the single-celled spore-forming fungiNosema apis,N. ceranae and N. neumanii, causing a severe loss on the colony vitality and productivity. Fumagillin, a MetAP2 inhibitor, was a certified treatment for controlling nosemosis, nevertheless, due to its deleterious effects on honey bees and humans, it is prohibited. So, searching for novel biological agents with affordable selectivity to target Nosema species infecting Apis mellifera, with nil toxicity to bees and humans is the main objective of this study. Nosema species were isolated from naturally infected honey bees. The methanolic extracts of Acacia nilotica, Elaeis guineensis, and Catharanthus roseus were tested to selectively control the growth of Nosema spp of honeybees. The spores of Nosema species were molecularly and morphologically identified. Among the tested plant extracts, the methanolic extracts (0.1%) of A. nilotica had the most activity towards Nosema spp causing about 37.8 and 32.5% reduction in the spores' load at 5- and 9-days post-infection, respectively, compared to the untreated control. At 0.1%, the A. nilotica methanolic extract exhibited the highest inhibitory effect for Nosema spores, without any obvious bee mortality. Catharanthus roseus displayed a reduction of spores by 27.02%, with bee mortality rate of 27.02%. At 1% for 5 dpi, the A. nilotica extracts led to 18.18% bee mortality, while the C. roseus extracts resulted in 100% mortality, as revealed from the toxicity and quantification bioassays. So, the extracts of A. nilotica and C. roseus had a significant effect in controlling the N. apis and N. ceranae titer compared to the infected untreated control at both time points. The titer of N. apis and N. ceranae was noticeably decreased by more than 80% and 90%, in response to A. nilotica, compared to the control. From the metabolic profiling by GC-MS analysis, the most frequent active compounds of A. nilotica were 2,4,6-trihy-droxybenzoic acid, 1,2-dihydroxybenzene, myristic acid, and linoleic acid. These compounds were analyzed in silico to assess their binding affinity to the ATP binding protein, methionine aminopeptidase and polar tube protein of Nosema species as target enzymes. The compound 2,4,6-trihydroxybenzoic acid had the lowest energy to bind with ATP binding protein, methionine aminopeptidase and polar tube protein of Nosema, followed by 1,2-dihydroxybenzene and myristic acid, compared to fumagilin. So, from the experimental and molecular docking analysis, the extracts of A. nilotica had the highest activity to attack the cellular growth machinery of Nosema species without an obvious effect to the honeybees, ensuring their prospective promising application.

Testing the efficacy of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) as a inundative biological control agent in Western Nebraska.

The western bean cutworm (Striacosta albicosta) is a primary pest of corn and dry edible bean, for which control measures are often warranted. Inundative releases of Trichogramma ostriniae have been used to control lepidopterous pests, such as the European corn borer (Ostrinia nubilalis), in eastern North America (e.g., New York, Virginia). However, no prior field studies have assessed T. ostriniae as a biological control agent in the North American Great Plains. Objectives for this study were (i) to determine the suitability of S. albicosta as a host for T. ostriniae and (ii) to assess the feasibility of T. ostriniae as a biological control agent of S. albicosta in Nebraska corn and dry edible bean fields. Dispersal and parasitism were monitored with yellow sticky cards and sentinel egg masses (O. nubilalis, S. albicosta, and Ephestia kuehniella) at 36 locations surrounding a central release point. Trichogramma ostriniae adults tended to be concentrated near the point of release. However, egg parasitism was so low that the minimum rates of T. ostriniae needed for effective control could not be determined. Our evidence indicates that the low parasitism measured in this study may indicate low suitability of T. ostriniae to Western Nebraska and, possibly, the Great Plains.

Seven New Species of Anastatus Motschulsky (Hymenoptera: Chalcidoidea: Eupelmidae) from China Identified Based on Morphological and Molecular Data

Anastatus is the second-largest genus in the family Eupelmidae, with 150 species found worldwide and fourteen known species in China. Most species in this genus are the primary parasitoids of insect eggs, particularly those of Lepidoptera and Hemiptera, and several species have been used for the biological control of various insect pests. In this paper, seven new species of Anastatus Motschulsky, 1859 (Hymenoptera: Eupelmidae) from China are described, of which A. caeruleus Wang and Peng n. sp. and A. garygibsoni Zhou and Peng n. sp. were reared from the eggs of Tessaratoma papillosa (Hemiptera: Tessaratomidae), while A. daiyunensis Wang and Peng n. sp., A. makrysourus Zhou and Peng n. sp., A. polikiarkoudus Wang and Peng n. sp., A. taibaiensis Wang and Peng n. sp., and A. zdenekbouceki Zhou and Peng n. sp. were collected by malaise traps or sweeping. The new species are all described and illustrated based on female specimens, and the key to all 21 Chinese Anastatus species, based on females, is provided. Partial COI sequences of A. caeruleus n. sp., A. garygibsoni n. sp., and A. taibaiensis n. sp. are provided, and a phylogenetic reconstruction based on maximum likelihood analyses, while showing similar results at high taxonomic levels to our morphological feature classification results, provides additional information on the placement of Anastatus at the species level.

The impact of humidity on the functional response of Blattisocius Mali (Acari: Blattisociidae) preying on the acarid mite Tyrophagus putrescentiae.

Humidity influences the life table parameters and foraging behaviours of various terrestrial arthropods. The soil mite, Blattisocius mali Oudemans is a potential biological control agent of some acarid mites, moths, and nematodes. In the current study, we investigated the functional response of B. mali preying on the eggs of the mould mite Tyrophagus putrescentiae Schrank (Acari: Acaridae) at different humidity levels between 33% and 92%. To determine the type of functional response, we used logistic regression and a generalized functional response equation suggested by Real. The functional response parameters were estimated using models proposed by Hassell and Cabello et al. Blattisocius mali exhibited Type II functional response at 33% and Type III at other tested humidities (52%, 72%, 82%, and 92%). The potential for prey mortality (α) was the highest, i.e., 0.05923, and the handling time was the shortest, i.e., 0.00463day, at 92% humidity, indicating the highest efficiency of B. mali at this humidity. Our findings revealed that B. mali was more efficient at higher humidity levels as compared to lower humidity levels. Humidity affected the predation rate and might have played an important role in stabilizing the predator-prey system by shifting the functional response with humidity.

Sex-ratio distortion in a weed biological control agent, Ceratapion basicorne (Coleoptera: Brentidae), associated with a species of Rickettsia.

Many endosymbionts of insects have been shown to manipulate and alter their hosts' reproduction with implications for agriculture, disease transmission, and ecological systems. Less studied are the microbiota of classical biological control agents and the implications of inadvertent endosymbionts in laboratory colonies for field establishment and effects on target pests or nontarget organisms. While native-range field populations of agents may have a low incidence of vertically transmitted endosymbionts, quarantine and laboratory rearing of inbred populations may increase this low prevalence to fixation in relatively few generations. Fixation of detrimental endosymbionts in founding biological control agent populations prior to release may have far-reaching effects. Significant female-biased sex-ratio distortion was found within laboratory populations of the weevil Ceratapion basicorne (Illiger), a classical biological control agent that was recently approved for use against yellow starthistle (Centaurea solstitialis L.). This sex-ratio distortion was observed to be vertically inherited and reversible through antibiotic treatment of the host insect. Molecular diagnostics identified a Rickettsia sp. as the only bacterial endosymbiont present in breeding lines with distorted sex ratios and implicated this as the first reported Rickettsia associated with sex-ratio distortion within the superfamily Curculionoidea.

Innovative Approaches for Sustainable Greenhouse Pest Management: Integrating Advanced Diagnostics and Preventive Strategies for Optimal Crop Health

Sustainable greenhouse pest management is critical for achieving good crop yields while reducing environmental impact. This paper investigates novel ways that incorporate improved diagnostic tools and preventive tactics into the framework of Integrated Pest Management (IPM) in greenhouse ecosystem. Understanding pest life cycles and utilizing cutting-edge tools such as DNA barcoding and enzyme-linked immunosorbent assays (ELISA) might help greenhouse managers achieve precise pest diagnosis and early responses. Preventive measures, such as tight cleanliness protocols, quarantine techniques, and the use of physical barriers, are critical in lowering pest incidence. Furthermore, biological controls, cultural methods such as crop rotation and intercropping, and the selective use of insecticides and biopesticides collectively help to ensure long-term pest management. This complete approach not only reduces insect damage but also creates a healthier, more resilient agricultural ecology. Furthermore, traditional diagnostic and preventive measures were also discussed in the article. The and recommendations are validated by recent studies and data, demonstrating the success of these integrated tactics in modern greenhouse operations.

Isolation and identification of antifungal, antibacterial and nematocide agents from marine bacillus gottheilii MSB1.

Pathogenic fungi employ numerous strategies to colonize plants, infect them, reduce crop yield and quality, and cause significant losses in agricultural production. The increasing use of chemical pesticides has led to various ecological and environmental issues, including the emergence of resistant weeds, soil compaction, and water pollution, all negatively impacting agricultural sustainability. Additionally, the extensive development of synthetic fungicides has adverse effects on animal and human health, prompting the exploration of alternative approaches and green strategies for phytopathogen control. Microorganisms living in sponges represent a promising source of novel bioactive secondary metabolites, potentially useful in developing new nematicidal and antimicrobial agents. This study focuses on extracting bioactive compounds from endosymbiotic bacteria associated with the marine sponge Hyrtios erect sp. (collected from NIOF Station, Hurghada, Red Sea, Egypt) using various organic solvents. Bacillus sp. was isolated and identified through 16S rRNA gene sequencing. The biocidal activity of Bacillus gotheilii MSB1 extracts was screened against plant pathogenic bacteria, fungi, and nematodes. The n-butanol extract showed significant potential as a biological fungicide against Alternaria alternata and Fusarium oxysporum. Both n-hexane and ethyl acetate extracts exhibited negative impacts against the plant pathogenic bacteria Erwinia carotovora and Ralstonia solanacearum, whereas the n-butanol extract had a positive effect. Regarding nematicidal activity, ethyl acetate and n-butanol extracts demonstrated in-vitro activity against the root-knot nematode Meloidogyne incognita, which causes serious vegetable crop diseases, but the n-hexane extract showed no positive effects. The findings suggest that bioactive compounds from endosymbiotic bacteria associated with marine sponges, particularly B. gotheilii MSB1, hold significant potential as alternative biological control agents against plant pathogens. The n-butanol extract, in particular, displayed promising biocidal activities against various plant pathogenic fungi, bacteria, and nematodes. These results support further exploration and development of such bioactive compounds as sustainable, environmentally friendly alternatives to synthetic pesticides and fungicides in agricultural practices.

Diversity of Diptera and their parasitoids associated with Inga vera Willd. (1806) (Fabaceae) with new host record in Minas Gerais, Brazil

Diptera belonging to four different families, as well as four associated parasitoids were reared from fruits of Inga vera Willd. (Fabaceae) in Lavras, Minas Gerais, southeast Brazil. We collected 450 fruits from five trees of I. vera between 2020 and 2021 in various localities situated within the University Federal of Lavras. We reared specimens belonging to four different dipteran families: Anastrepha distincta Greene (Tephritidae), Asteromyia sp. (Cecidomyiidae), Drosophila zottii Vilela (Drosophilidae), and Neosilba pendula (Bezzi) (Lonchaeidae). Lopheucoilasp.(Hymenoptera: Figitidae) probably is a parasitoid of N. pendulawhereas Eupelmus sp. (Hymenoptera: Eupelmidae), and two species of Sycophila (Hymenoptera, Eurytomidae) appear to be parasitoids of Asteromyia sp.. We additionally conducted molecular characterization using the DNA barcoding locus for the majority of the species reared in this study. This study provides valuable insights into the biology and ecology of frugivorous flies in Brazil, and sheds light on potential biological control agents, enabling better management practices.

Strain-Specific Infection of Phage AP1 to Rice Bacterial Brown Stripe Pathogen Acidovorax oryzae

Bacteriophage (phage) AP1 has been reported to effectively lyse Acidovorax oryzae, the causative agent of bacterial brown stripe in rice. However, phage AP1 exhibits strain-specific lysis patterns. In order to enhance the potential of phages for biological control of rice bacterial brown stripe, this study investigated the possible mechanism of strain-specific infection by characterizing phage AP1 and its susceptible (RS-2) and resistant (RS-1) strains. Based on the current classification standards and available database information, phage AP1 was classified into the class Caudoviricetes, and it is a kind of podophage. Comparative analysis of the susceptible and resistant strains showed no significant differences in growth kinetics, motility, biofilm formation, or effector Hcp production. Interestingly, the resistant strain demonstrated enhanced virulence compared to the susceptible strain. Prokaryotic expression studies indicated that six putative structural proteins of phage AP1 exhibited varying degrees of binding affinity (1.90–9.15%) to lipopolysaccharide (LPS). However, pull-down assays and bacterial two-hybrid analyses revealed that only gp66 can interact with four host proteins, which were identified as glycosyltransferase, RcnB, ClpB, and ImpB through immunoprecipitation and mass spectrometry analyses. The role of LPS in the specific infection mechanism of phage AP1 was further elucidated through the construction of knockout mutant strains and complementary strains targeting a unique gene cluster (wbzB, wbzC, wbzE, and wbzF) involved in LPS precursor biosynthesis. These findings provide novel insights into the mechanisms of phage-host specificity, which are crucial for the effective application of phage AP1 in controlling rice bacterial brown stripe.

An Algerian Soil-Living Streptomyces alboflavus Strain as Source of Antifungal Compounds for the Management of the Pea Pathogen Fusarium oxysporum f. sp. pisi

Fusarium wilt caused by Fusarium oxysporum f. sp. pisi (Fop) poses significant threats to pea cultivation worldwide. Controlling this disease is mainly achieved through the integration of various disease management procedures, among which biological control has proven to be a safe and effective approach. This study aims to extract and identify antifungal secondary metabolites from Streptomyces alboflavus KRO3 strain and assess their effectiveness in inhibiting the in vitro growth of Fop. This bacterial strain exerts in vitro antagonistic activity against Fop, achieving highly significant inhibition over one week. The ethyl acetate extract, obtained from its ISP2 agar medium culture, also exhibited strong antifungal activity, maintaining an inhibition rate of approximately 90% at concentrations up to 250 µg/plug compared to the control. Thus, the organic extract has been fractionated using chromatographic techniques and its bioguided purification allowed us to isolate the main bioactive compound. This latter was identified as metacycloprodigiosin using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and specific optical rotation data. Metacycloprodigiosin demonstrates dose-dependent inhibitory activity against the phytopathogen with an effective concentration of 125 µg/plug. The other secondary metabolites present in the ethyl acetate extract were also identified by gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). This study highlighted the potential of S. alboflavus KRO3 strain and its antimicrobial compounds for the management of the pea pathogen Fusarium oxysporum f. sp. pisi.

Rediscovery of Microbrachida Bierig, 1939, description of a new species from the Brazilian Amazon and its potential for biological control (Coleoptera, Staphylinidae)

The genus Microbrachida was described by Alexander Bierig based on one tiny rove beetle. Since then, it has not been studied. Recently, a set of small rove beetle specimens were collected in the heart of the Brazilian Amazon, where they occur foraging mushrooms that grow on logs of cultivated trees. These mushrooms cause an infection known as witches' broom disease on those plants. Here, we redescribe Microbrachida and describe a new species in it. We also provide images of the diagnostic characteristics of the genus (including scanning electron micrographs), a key to the New World genera of Gyrophaenina, a key to the species of Microbrachida and a preliminary discussion about the potential biological control of the new species.

Crop rotation and fungicides impact microbial biomass, diversity and enzyme activities in the wheat rhizosphere

Sustainable crop production systems should promote large and diverse soil microbial communities to enhance biological soil processes rather than depend solely on chemical interventions that include pesticide applications. Crop rotation increases above-ground temporal diversity which, relative to monoculture, usually increases soil microbial diversity. But comparisons between short and long crop rotations that also include pesticide effects are rare. A 5-yr (2013-2017) field study was conducted to investigate crop rotation and fungicide effects on the soil microbiome and activity. There were nine rotations, with or without fungicide applications, that included four 2-yr rotations (wheat preceded by canola, barley, pea, or flax), four 3-yr rotations where barley or canola were added to the 2-yr rotations, and one rotation where canola and wheat were stacked (canola-canola-wheat-wheat). In 2017, soil microbial biomass, composition, diversity and enzyme activities were measured in the rhizosphere of the final wheat crop in each rotation. Fungicides reduced fungal richness (the number of different fungal taxa) in the wheat rhizosphere (e.g., Chao1 indices of 64.0 vs. 79.9) especially in 2-yr rotations, but rotation length/type and the crops that preceded wheat had different effects on different taxa. Two of the three most predominant prokaryotic phyla, Proteobacteriota and Actinobacteriota, responded differently to rotation length: 3-yr rotations enriched the former (27.4% vs. 20.1% relative abundances), but 2-yr rotations enriched the latter (19.9% vs. 28.3% relative abundances). Relative to oilseed crops preceding the sampled wheat, a field pea preceding crop enriched Actinobacteriota (31.7% vs. 24.8% relative abundances) and the most abundant fungal class, Sordariomycetes (39.1% vs. 22.1% relative abundances), in addition to increasing microbial biomass carbon (MBC) and arylsulphatase activity by 33% and 57%, respectively. Correlations of the relative abundances of fungal or prokaryotic genera with β-glucosidase and arylsulphatase activities were similar (both positive or negative), but they were the opposite of correlations with acid phosphomonoesterase, suggesting a close link between C and S cycling. Besides the nutrient cycling implications of these soil microbial characteristics, there is need to study their biological disease control significance.

Overview of Brinjal (Solanum melongena L.) Pests and Their Management: A Review

Brinjal (eggplant or aubergine), a widely cultivated vegetable in tropical and subtropical regions, faces significant threats from a variety of insect pests. These pests cause substantial damage at different stages of crop growth, leading to reduced yields and compromised fruit quality. This review provides a comprehensive overview on the major insect pests that affect brinjal cultivation, focusing on their biology, damage mechanisms, and current management practices. Special emphasis is placed on integrated pest management (IPM) strategies, combining cultural, biological and chemical control methods to promote sustainable brinjal production.

Atractylodes macrocephala Root Rot Affects Microbial Communities in Various Root-Associated Niches

Atractylodes macrocephala, a perennial herb widely used in traditional Chinese medicine, is highly prone to root rot, which significantly reduces its yield and quality. This study compared the physicochemical properties of soil from healthy and diseased A. macrocephala plants and analyzed the microbial diversity in the endophytic, rhizosphere, and root zone soils. The results showed that the diseased plants had higher levels of available potassium and electrical conductivity in the rhizosphere, both positively correlated with the severity of root rot, while soil pH was negatively correlated. The diversity and richness of endophytic bacterial and fungal communities were significantly reduced in diseased plants. Additionally, root rot led to major changes in the rhizosphere microbial community, with an increased abundance of Proteobacteria and Ascomycota, and a decrease in Firmicutes, Bacteroidetes, Actinobacteria, and Basidiomycota. Fusarium oxysporum, Fusarium solani, and Fusarium fujikuroi were identified as key pathogens associated with root rot. This study enhances our understanding of the microbial interactions in soils affected by root rot, offering a foundation for developing soil improvement and biological control strategies to mitigate this disease in A. macrocephala cultivation.

The economic, social, and environmental impact of ecologically centered integrated pest management practices in East Africa

Agricultural pest management faces mounting challenges with increasing pressure to reduce chemical pesticide use while ensuring food security, and environmental sustainability. Ecologically centered approaches, such as integrated pest management (IPM), offer promising sustainable agroecological crop protection alternative solutions to pesticides. This study assesses the investment viability and environmental sustainability of two IPM interventions—mango fruit fly IPM (FF-IPM) and push-pull technology (PPT) in Kenya and Uganda, using project investment and adoption data from 2007 to 2021. The study also evaluates these technologies contribution to food security and poverty reduction. FF-IPM integrates biological control, cultural practices, and targeted bait traps to manage fruit flies in mango production, while PPT employs Desmodium and Brachiaria grass to control stemborers and striga weed. The findings highlight that these IPM interventions achieved a combined net present value of $500 million, with a benefit-cost ratio of about 8:1, and an internal rate of return of 21%, comparable to returns from improved crop varieties. These technologies also improved food security for 641,000 people, lifted 445,349 people above the poverty line, representing 2% of the poor population in both countries, and generated an average income increase of $5 per capita in Kenya and Uganda annually. Environmentally, they sequestered 2.7 million tons of CO2 equivalent, valued at $12.2 million, and are reducing pesticide use by 86,000 to 204,000 L per year. These results demonstrate the potential of IPM approaches to simultaneously enhance livelihoods, local economies, and generate global environmental public goods, suggesting that addressing adoption barriers could further amplify these positive outcomes.

Characterization of autochthone biological control agents for pear protection against the brown spot of pear disease caused by Stemphylium vesicarium

AbstractStemphylium vesicarium is an important phytopathogen for many plant species, that switches between necrotrophic and saprophytic lifestyles. In the last decade, it has severely affected pear production worldwide, causing the so-called brown spot of pears (BSP), which led to the replacement of several pear orchards in northern Italy with consequent important economic losses. In the field, the management of the disease still relies on fungicide application, though several resistant genotypes of the pathogen emerged through the years. In the present study, three different bacterial species have been isolated from an infected orchard and evaluated as potential biological control agents (BCAs) against a local isolate of Stemphylium vesicarium. Two bacterial isolates belonging to the Bacillus genus demonstrated a significant ability to inhibit S. vesicarium growth in vitro, both through direct antagonism and the emission of volatile organic compounds (VOCs). The cell-free supernatant from one of these isolates exhibited a strong biocontrol activity, particularly through compounds extracted in acidic conditions. The protective effectiveness of the two most promising BCAs was further validated on detached pear fruits infected with S. vesicarium. Overall, the findings suggest that these two BCAs have the potential to be developed into a bio-based alternative to fungicides to control BSP, thus contributing to a more sustainable pear production.

Parasitism by Aleiodes ceres Shimbori, 2023 (Hymenoptera: Braconidae) of three species of Spodoptera Guenée, 1852: effects of preferential instar and host diet

AbstractA recently discovered koinobiont parasitoid species, Aleiodes ceres Shimbori, 2023, proved to be a promising biological control agent for larvae of Spodoptera cosmioides (Walker, 1858), S. eridania (Stoll, 1782), and S. frugiperda (J.E. Smith, 1797), all well-known pests that cause critical damage to soybean and corn crops. This study investigated the potential of parasitism by A. ceres in these three species, including different instars (1st, 2nd, 3rd, and 4th instar) and diets (artificial and natural). Parasitism was highest when it occurs in the second instar for all three host species. The egg-to-pupa period of A. ceres was shorter in the second and third instars in relation to the first instar. Parasitism was substantially enhanced by the use of natural diets (soybean and corn leaves) compared with the artificial diet in all three species of the Spodoptera complex, suggesting a possible allelochemical interaction. Based on the results from the three host species, the potential for control of Spodoptera spp. by A. ceres was evident.

Mechanisms of Biocontrolling Action of Yeasts in Post-Harvest Fruit: A Review

Objective: The aim of the research is to address the biological control developed by yeasts in the post-harvest of fruits, based on a brief literature review on the subject. Theoretical Framework: The use of chemical control mechanisms and biocontrol is based on the increasing need for sustainable agricultural practices that ensure human health and environmental preservation. While synthetic fungicides are effective in combating fungal diseases, their excessive use raises concerns about pathogen resistance and public health risks. In this context, the development of biocontrol agents, such as yeasts, emerges as a viable and ecological alternative, promoting food safety and crop protection with a lower environmental impact. Method: A narrative literature review was conducted using major scientific databases to collect articles on the biological control of yeasts in the post-harvest of fruits. Key studies were evaluated to measure effectiveness and understand the mechanisms related to the biocontrol action of these yeasts. Results and Discussion: The predominant chemical control for fungal diseases is being replaced by sustainable alternatives, such as yeast-based biofungicides, which demonstrate effectiveness against pathogens in post-harvest settings. Mechanisms such as killer activity and the production of hydrolytic enzymes stand out in biocontrol. Although promising, further research is needed to deepen the understanding of biocontrol agents and their applications.