Biological Control Research Articles

Optimizing aquatic weed management in Lake Ossa, Cameroon: Harnessing the power of biological control and real-time satellite monitoring

Salvinia, Salvinia molesta Mitchell (Salviniaceae) is a free-floating aquatic fern native to Brazil and considered one of the worst weeds in the world. When left unchecked, salvinia forms dense mats on the water surface, limiting sunlight penetration and altering water quality that disrupt ecosystem processes. In 2016, salvinia was first reported in Lake Ossa, Cameroon, and by summer 2021, had expanded to cover almost 49 % of the lake’s 4,000-hectare surface. A multinational team initiated a biological control and monitoring program, importing the salvinia weevil, Cyrtobagous salviniae Calder & Sands (Coleoptera: Curculionidae) from Louisiana, USA, in summer 2021. The objectives of this study were to: quantify the changes in salvinia cover and other floating vegetation, document the establishment and impact of the biological control program, and deliver a tool for near-real time monitoring of floating vegetation. We developed a satellite-based remote sensing application to document in near real-time the changes in coverage of floating vegetation. Using this tool, we quantified the reduction in the salvinia coverage by 80 % within three years of the release of the weevil. Field surveys in 2022 and 2023, demonstrated weevil establishment in the lake and widespread salvinia browning that was associated with weevil damage. Linear regressions of the percent cover of floating vegetation over time, demonstrated that after the weevil release, the rate of change decreased to −1.7 % per 60 days. Field monitoring and satellite imagery showed the establishment of a sedge (Oxycaryum sp., Cyperaceae) within the salvinia mat in late 2021. This secondary invasion slowed the reduction in coverage of floating vegetation from −1.7 % to −0.6 % per 60 days, and warrants further research. By late 2023, the revitalization of Lake Ossa restored fishing and transportation opportunities for the community, and also the comeback the emblematic African manatee. The success of the biological control of salvinia in Lake Ossa is not surprising due to its tropical conditions. However, it highlights the importance of early intervention and continuous monitoring. We propose that the integration of biological control and remote sensing technology is becoming more accessible and can be automated; therefore, a replicable model for future invasive weed programs around the world.

Neem (Azadirachta indica A. Juss; Meliaceae) as the source for plant-based pesticides as an effective and sustainable biocontrol alternative

The neem tree has strengths such as effective and environmentally friendly active compounds, as well as the ability to improve the quality and productivity of plants organically. However, the use of botanical pesticides has several challenges, such as potentially lower effectiveness compared to chemical insecticides, high production costs, and requiring specific knowledge in formulation and application. Botanical pesticides are readily available tools for insect pest management and are eco-friendly. The research results show that a neem formula at a concentration of 20 ml.l-1 water can cause mortality of brown planthopper is 48.75 - 70%, while mortality in the synthetic insecticide (positive control) at a concentration of 2 ml.l-1 water (as recommended) resulted in 45% mortality. It is obvious that there is a need to develop biological control as alternatives for eco-friendly and sustainable for pests’ control in insect’s pest management strategies. This research study has both qualitative and quantitative approach, data collection strategies were desk review of information and will be based on empirical data and literature. For the desk study, relevant internet web pages were browsed to have an overview of the key concepts of the research issue, problem of pests and diseases control and benefit of neem tree as botanical pesticides. Nevertheless, the use of botanical pesticides can provide long-term benefits to the environment and human health and support more sustainable agriculture. There is a great opportunity for the development of more effective and affordable technology for botanical pesticide production for farmers, but there are also threats such as strong competition from synthetic pesticides. The objective this study aims to determine the potential of neem (Azadirachta indica A.Juss) as a plant producing botanical pesticides as an effective and sustainable biological control alternative.

A novel antifungal peptide, SP1.2, from Rhodopseudomonas palustris against the rice blast pathogen.

Rice blast has a significant detrimental impact on rice yields, so developing efficient biological control technologies is an effective means for rice blast prevention and control. The GroEL protein has proven to be effective at preventing and managing the pathogenicity of rice blast. Here, we analyzed the amino acid sequence of the GroEL protein and synthesized the '60 kDa chaperonin signature' (350-373 amino acids) peptide SP1.2, which has potent antifungal activity. Notably, the SP1.2 peptide exhibited potent fungicidal activity against Magnaporthe oryzae, effectively inhibiting appressorium germination. Electron microscopy revealed that SP1.2 disrupted the fungal plasma membrane and bound to multiple bioactive phosphoinositides in vitro, triggering the production of reactive oxygen species. Furthermore, it also caused an increase in the acetylation of M. oryzae and induced autophagy in cells. The spray application of SP1.2 significantly reduced the number of disease spots caused by the fungal pathogen M. oryzae in rice, enhancing the defense response of rice plants. Field trials showed that the control effect was 64.59% after spraying SP1.2. Our study illustrates the antifungal activity of the structurally unique SP1.2 peptide against plant fungal pathogens and paves the way for the future development of this class of peptides as antifungal agents. © 2024 Society of Chemical Industry.

Polyphasic approach to the selection of Esteya isolates for the control of the pinewood nematode, Bursaphelenchus xylophilus

Pine wilt disease, caused by the pinewood nematode, Bursaphelenchus xylophilus, is a major phytosanitary concern to pine forests worldwide. Managing pine wilt disease involves a complex logistical undertaking, with limited effectiveness and significant ecological repercussions. An increasing demand for biosolutions has sparked an interest in microbial antagonists capable of controlling the nematode. Esteya spp. are promising fungal biocontrol agents of the pinewood nematode. Here, we carry out an integrative characterization of E. vermicola and E. floridanum isolates, through biological, biochemical, and molecular methods, and provide insights into the selection of these isolates for the biological control of the pinewood nematode. Dual culture assays revealed that Esteya spp. can compete with ophiostomatoid fungi (Leptographium terebrantis and Ophiostoma ips) occurring in the pathosystem of pine wilt disease, an often-neglected ecological perspective that could hinder their success as biocontrol agents. Moreover, E. vermicola can metabolize more carbon sources than E. floridanum, which can have implications on their successful establishment in pine trees. Our experimental approach further shows that both Esteya spp. are equally competent in suppressing the pinewood nematode in vitro. Overall, our results suggest that a prophylactic application of Esteya in pine trees may be preferable for optimal bioprotective effects against the pinewood nematode and fungal pathogens.

Fusarium oxysporum and soil nutrient amendments provide short-term inhibition of Cosmopolites sordidus raising questions on biopesticide and plant nutrition potentials in tissue culture banana

Endophytic Fusarium oxysporum strain V5w2 has been suggested to offer the ecosystem service of suppressing Cosmopolites sordidus and other pests that attack tissue culture banana plants in agroecosystems. The effects of endophytic F. oxysporum V5w2 and nutrient supply on C. sordidus in potted tissue culture banana plants were investigated. In the screenhouse, rhizome damage by C. sordidus larvae was lower in F. oxysporum V5w2-inoculated plants than in non-inoculated ones. Banana plants inoculated with F. oxysporum V5w2 were larger and suffered less rhizome damage but with low chlorophyll content. Weights of C. sordidus larvae were not different between those reared on F. oxysporum V5w2-inoculated banana plants and the non-inoculated ones. Larval C. sordidus from nutrient-treated plants had lower weight than those that fed on plants that did not receive nutrients. In the field, fewer adult C. sordidus were found on F. oxysporum V5w2-inoculated banana plants than on non-inoculated plants 12 h after insect release. The number of adult C. sordidus and their eggs did not vary between F. oxysporum V5w2-inoculated banana plants and controls at the end of the experiment. Adult C. sordidus did not discriminate between nutrient-treated banana plants and those without nutrient treatment. However, non-beneficial interactions between F. oxysporum V5w2 and plant-parasitic nematodes negate the chances of its application as an endophytic biological control agent. In conclusion, while F. oxysporum V5w2 is not quite viable for application as an endophytic biological control agent for C. sordidus and other banana pests, this fungus may still have some potential to offer alternative ecosystem services through the provisioning of pest-inhibitive organic compounds.

Dispersal ability of the predatory mites Blattisocius tarsalis and Cheyletus malaccensis in grain piles and storage facilities

Predatory mites can be released into storage facilities to control various stored product pests. However, their ability to disperse within grain piles and structures (warehouses and processing facilities) has not been well assessed. This study aimed to evaluate two predatory mites, Blattisocius tarsalis and Cheyletus malaccensis, as biological control agents by examining their dispersal abilities in piles of rice grains and storage facilities. The mites were evaluated for their capacity to navigate vertically through polyvinyl chloride (PVC) tubes filled with paddy rice at depths of 40 and 100 cm to determine if they could reach the eggs of various lepidopteran pests at the bottom. Additionally, their dispersal ability over varying time intervals and their preferences concerning light intensity were assessed in 2-metre-long channels coated with rice flour residues. An integrated assessment of their vertical and horizontal dispersal capacities, along with the influence of light, was conducted in a controlled pilot storage room (4 × 3 × 3 m). Blattisocius tarsalis demonstrated impressive dispersal capabilities, reaching pest eggs at vertical depths of 40 and 100 cm through rice and dispersing 2 m horizontally in just 4 h. This proficiency extended to pilot storage room conditions, where it successfully navigated all distances, both horizontally and vertically, showing a preference for navigating away from the light. Cheyletus malaccensis proved to be an effective predator at close range to pest eggs but demonstrated limited dispersal capabilities in complex setups. This study underlines the suitability of B. tarsalis as a biological control agent capable of dispersing in various environments. Conversely, the utility of C. malaccensis may be more specialised and effective within a narrow movement range. These findings highlight the importance of understanding mite dispersal behaviours for optimising pest management strategies and contributing to the more sustainable and effective storage of rice grains.

Susceptibility of Lymantria dispar to Beauveria bassiana under short-term Cd stress: humoral immunostimulation cannot offset cellular immunotoxicity

Heavy metal is a serious environmental pollutant with all kinds of biotoxic effects. The immunomodulatory effects of Cd stress on Lymantria dispar larvae and its underlying mechanisms were investigated. The susceptibility of Cd-treated larvae to Beauveria bassiana (Bb) was significantly increased by 27.50%. The hemocyte count, melanization, encapsulation activities, and expression levels of related regulatory genes (e.g. PPO1 and DSCAM) in the Cd and Cd+Bb groups were markedly lower than those in CK and CK+Bb groups. Hemocyte compensation through the apoptosis inhibitor significantly increased the melanization, encapsulation, and the survival rate of larvae in the Cd+Bb group by 100.00%, 74.03%, and 18.33%, respectively. The expression of signal transduction and effector genes (e.g. Gloverin) was significantly elevated in Cd-treated larvae both before and after Bb infection. Silencing Gloverin resulted in a 9.17% increase in susceptibility of Cd-treated larvae to Bb. Cd exposure induced humoral immunostimulation in larvae through the CncC-Gloverin pathway, as evidenced by that silencing CncC resulted in a 71.07% decrease in Gloverin expression and a 19.73% increase in larval mortality in Cd+Bb group. Overall, the humoral immunostimulation induced by Cd stress in L. dispar larvae were insufficient to counteract the cellular immunotoxicity during Bb infection. Environmental implicationHeavy metal is a serious environmental pollutant with all kinds of biotoxic effects. In this study, the immunomodulatory effects of Cd stress on Lymantria dispar larvae and its underlying mechanisms were investigated. To our knowledge, this is the first study to investigate how heavy metal exposure modifies insect innate immunity. The findings of this study will facilitate a comprehensive evaluation of the immune modification effects of heavy metals and provide insights for optimizing biological control strategies for pests in heavy metal-polluted areas.

Lactic Acid Bacteria As Biological Control Agent For Controlling Aspergillus Growth and Aflatoxin Production: A Review

: Aspergillus sp., a ubiquitous filamentous fungus, poses significant challenges to the food industry as a common spoilage and mycotoxin producing organism. The conventional use of chemical preservatives to control Aspergillus contamination raises concerns about potential health risks and environmental impacts. Therefore, alternative approaches, such as the utilization of natural biopreservatives, as inexpensive, safe, and promising mycotoxin decontamination strategies are being explored. Lactic acid bacteria have gained considerable attention as potential candidates due to their antimicrobial properties and long-standing safe use in food fermentation. This review provides a thorough summary of the potential of lactic acid bacteria as biopreservatives against Aspergillus sp. The inhibitory mechanisms of lactic acid bacteria against the proliferation of Aspergillus and mycotoxin yield are explored, highlighting the role of organic acids, antimicrobial peptides, and other bioactive compounds. The versatile application of lactic acid bacteria based natural preservatives across a range of food matrices, storage conditions, etc. is also addressed. Further research is warranted to optimize lactic acid bacteria strains, explore synergistic combinations, and investigate their efficacy in real food systems. Implementing lactic acid bacteria based biopreservative strategies could significantly enhance food safety and quality by reducing Aspergillus contamination and mycotoxin risks.

Diel dissolved organic matter patterns reflect spatiotemporally varying sources and transformations along an intermittent stream

AbstractStream dissolved organic matter (DOM) is a globally important carbon flux and a locally important control on stream ecosystems, and therefore understanding controls on stream DOM fluxes and dynamics is crucial at both local and global scales. However, attributing process controls is challenging because both hydrological and biological controls on DOM are integrated and may vary over time and throughout stream networks. Our objective was to assess the patterns and corresponding controls of diel DOM cycles through a seasonal flow recession by using reach‐scale in situ sensors in a non‐perennial stream network. We identified five characteristic diel variations in DOM with differing phase and amplitude. During snowmelt flows, diel variations in DOM were consistent among sites and reflected diel flowpath shifts and photodegradation. Evapotranspiration‐driven diel stage oscillations emerged at two upstream sites, shaping diel DOM patterns indirectly, by creating conditions for instream DOM processing. At a spring‐fed site, minimal diel variation was observed throughout the summer whereas at an intermittent reach, daily drying and rewetting created biogeochemical hot moments. This research demonstrates that controls on DOM vary over time and space, even in close proximity, generating asynchronous fDOM patterns during low flows, illuminating shifts in biogeochemical processes and flowpaths.

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.