Control Agents Research Articles

Reproductive parameters of a new biocontrol agent, Eupeodes americanus (Diptera: Syrphidae) and comparison with the commercialized Aphidoletes aphidimyza (Diptera: Cecidomyiidae).

The American hoverfly Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) is an aphidophagous predator during its larval stage and is currently being evaluated for inclusion in biocontrol programs as a new biocontrol agent. However, little is known about its reproductive aptitudes. The objective of the present study was to determine the reproductive parameters of E. americanus and to compare them with those of a commercialized and widely used biological control agent for aphids, the aphid midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). The preoviposition period, oviposition period, adult longevity, lifetime and daily fecundity, egg hatching rate, and fertility were determined for E. americanus females and compared to those of A. aphidimyza. Trials were conducted under laboratory conditions in rearing cages on the broad bean plant Vicia faba L. (Fabaceae), infested with pea aphids Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the preoviposition period, oviposition period, and adult longevity were significantly longer in E. americanus than in A. aphidimyza. The daily fecundity and egg-hatching rate were similar in both species. However, lifetime fecundity and fertility were considerably higher in E. americanus than in A. aphidimyza. This study demonstrates that the reproductive capacity of E. americanus is clearly superior to that of A. aphidimyza and therefore supports its inclusion in the aphid pest management program as a new biocontrol agent.

Peptide-based immunoprotection against Rhipicephalus microplus tick

The main agents for tick control are chemical acaricides. However, when used without technical guidance, they can lead to environmental damage and the development of resistant tick strains. In this context, vaccines are alternative o be used in integrated tick management format by combining with other effective tools. We isolated RNA from ticks Rhipicephalus microplus, prepared the library, and performed next-generation sequencing; a pipeline analysis was applied to identify the hypothetical proteins having immunogenic potential and their predicted immunogenic peptides. Twelve peptides, ranging from 12 to 38 amino acid residues, containing the selected epitopes from different targets were selected and synthesized in two forms: the pure peptide; and the peptide conjugated to keyhole limpet hemocyanin (KLH) carrier. These peptides were divided into two groups of six peptides each. The antigen formulations (groups 1 and 2) were prepared with conjugated peptides containing 200 µg of each peptide per dose emulsified with Montanide ISA 61VG (SEPPIC); the control treatment had the adjuvant formulation without peptides (group 3). To evaluate the protective efficacy, 15 weaned male calves (Angus breed) aged around 6 months to one year and weighing approximately 200–250 kg were divided into three groups of five animals each; they were immunized thrice, at an interval of 28 days. After immunization, all the calves infested with 15,000 larvae of Rhipicephalus microplus. Peptide epitopes were recognized by antibodies against host-specific IgGs using indirect ELISA. The mean of the antibody level was determined for each group and compared using analysis of variance with two factors (ANOVA). F-test was used to determine the significance of differences observed between the groups. The percentage efficacy was calculated based on the number of ticks, the weight of teleoginas, and the weight and hatchability of the eggs, compared to that in the control group. The evaluation of immunoprotection indicated efficacies of 69 and 51 %, respectively in Group 1 and 2.

A comprehensive review of long‐distance hover fly migration (Diptera: Syrphidae)

Abstract Hover flies (Diptera: Syrphidae) are a group of insects containing many migratory species that provide critical ecosystem services including pollination, decomposition and biological control. Their migratory behaviour remains largely overlooked and unacknowledged, but an influx of contemporary research is beginning to shift this. The goal of this review is to summarise and synthesise the past 150+ years of global hover fly migration research from over 50 papers in multiple languages. Here, we provide comprehensive evidence for hover fly migration through the lens of the methodologies used for studying these phenomena, the biological mechanisms for migration and the associated ecological and economic impacts. We also include an inventory of all recognised migratory species and discuss taxonomic patterns. In total, we compiled accounts of 46 species that are considered migratory, most of which were sourced from Europe. Recent reports, however, have also described hover fly migration in North America, Asia, the Middle East and Australia. Approximately 70% of these species are from the subfamily Syrphinae, which are important biological control agents. The migratory behaviour of hover flies has substantial impacts on ecosystem services and may be linked to long‐distance gene flow for many angiosperms via pollen transportation. These insects are also likely redistributing biological control services at a continental scale on an annual basis, which has major repercussions for the management of crop pests such as aphids. The sensitivity of hover fly migration to anthropogenic impacts is not well known, but shifting climatic conditions, pollution and increased habitat fragmentation are likely impactful and should be further explored. Despite recent advances and increased interest in the subject, hover fly migration remains understudied and many major knowledge gaps continue to persist.

Characterization and Identification of Potential Lactic Acid Bacteria as Biological Control Agent against Ralstonia syzygii subsp. celebesensis of the Banana Blood Disease

Banana is one of the primary fruits cultivated in Malaysia and currently decimated by the emergence of a disease, known as banana blood disease (BBD) which caused by Ralstonia syzygii subsp. celebesensis (Rsc). The BBD has significantly affected the yield and profits of the worldwide banana industry. To date, various approaches including chemical and biological controls have been attempted to manage this disease but none of them succeed in controlling the disease. The uses of lactic acid bacteria (LAB) in managing plant diseases have been reported earlier but little information is available. Therefore, this project is designed to identify and investigate potential plant-associated LAB as biological control agent (BCA) against Rsc by using agar well diffusion method. The inhibition zones of each well were observed after 72h and the isolated LAB that showed inhibition zones were proceed for molecular characterization using PCR amplification followed by gel electrophoresis. The sequences were used for phylogenetic analysis. In addition, each of the potential LAB were used to identify their morphological characterizations and biochemical testing. Throughout the study, the highest inhibition zones of LAB from kimchi and fermented milk achieved a diameter of 21.30 mm and 28.70 mm, respectively. Kimchi isolates showed the highest similarity which is 97% as Lactiplantibacillus plantarum species. Among the fermented milk isolates, the highest similarity which is 98% identified as Lacticaseibacillus paracasei.

Characterization and screening of new Metarhizium isolates to control the coconut rhinoceros beetle in the Pacific islands

The coconut rhinoceros beetle (CRB; Oryctes rhinoceros) is one of the most destructive insect pests of coconut and oil palms in tropical Asia and the Pacific islands. Members of a new variant, known as CRB-G (clade I), have recently spread into the Pacific islands, causing significant damage. Biopesticides containing Metarhizium spp. are the strongest candidates for inundative biological control against the emerging CRB threat. Selection of the most virulent and robust isolate may determine the impact of this control option on the pest. In this work, CRB specimens with natural fungal infection were collected in Papua New Guinea (PNG) and Solomon Islands (SI). Putative entomopathogenic fungi were isolated and identified. These new isolates and some previously obtained from other Pacific countries were molecularly identified, characterized, and tested for virulence against CRB larval populations in PNG and SI in laboratory bioassays. Of the new isolates collected, four obtained from SI were identified as Metarhizium majus (conidia length ⁓11–15 μm), and four from PNG were identified as Metarhizium pingshaense (conidia length ⁓4–6 μm). The most virulent isolate was M. majus AgR-F717, which caused 100 % mortality in 20–23 days against a CRB variant from the CRB-S grouping (clade II) in laboratory bioassays carried out in PNG. Isolates of M. pingshaense did not show pathogenicity against CRB larvae. M. majus AgR-F717 was also the most virulent in laboratory bioassays using the mixed SI population (from both CRB-S and CRB-G groupings) and was selected for further evaluation using artificial breeding sites. Under field conditions, this isolate demonstrated its ability to infect CRB, dispersal up to 100 m from treated artificial breeding sites, and persistence in soil for at least four months. The new isolate AgR-F717 of M. majus has demonstrated potential as an augmentative biological control agent for CRB in PNG and SI.

Effect of herbicides on the redox metabolism and longevity of Lema praeusta (Fab.) (Coleoptera: Chrysomelidae): a biological control agent of Commelinaceae weeds

Effect of herbicides on the redox metabolism and longevity of Lema praeusta (Fab.) (Coleoptera: Chrysomelidae): a biological control agent of Commelinaceae weeds

Calcium Ion-Coupled Polyphosphates with Different Degrees of Polymerization for Bleeding Control.

The development of efficient hemostatic materials is crucial for achieving rapid hemorrhage control and effective wound healing. Inorganic polyphosphate (polyP) is recognized as an effective modulator of the blood coagulation process. However, the specific effect of polyP chain length on coagulation is not yet fully understood. Furthermore, calcium ions (Ca2+) are essential for the coagulation process, promoting multiple enzyme-catalyzed reactions within the coagulation cascade. Hence, calcium ion-coupled polyphosphate powders with three different degrees of polymerization (CaPP-n, n = 20, 50, and 1500) are synthesized by an ion-exchange reaction. CaPP exhibits a crystalline phase at a low polymerization degree and transitions to an amorphous phase as the polymerization degree increases. Notably, the addition of Ca2+ enhances the wettability of polyP, and CaPP promotes hemostasis, with varying degrees of effectiveness related to chain length. CaPP-50 exhibits the most promising hemostatic performance, with the lowest blood clotting index (BCI, 12.1 ± 0.7%) and the shortest clotting time (302.0 ± 10.5 s). By combining Ca2+ with polyP of medium-chain length, CaPP-50 demonstrates an enhanced ability to accelerate the adhesion and activation of blood cells, initiate the intrinsic coagulation cascade, and form a stable blood clot, outperforming both CaPP-20 and CaPP-1500. The hemostatic efficacy of CaPP-50 is further validated using rat liver bleeding and femoral artery puncture models. CaPP-50 is proven to possess hemostatic properties comparable to those of commercial calcium-based zeolite hemostatic powder and superior to kaolin. In addition, CaPP-50 exhibits excellent biocompatibility and long-term storage stability. These results suggest that CaPP-50 has significant clinical and commercial potential as an active inorganic hemostatic agent for rapid control of bleeding.

Larvicidal potency of four Egyptian herbs on Culex pipiens larvae: Phytochemical composition and molecular networking for most potent extracts

Utilizing synthetic insecticides to control mosquito populations has many adverse side effects as they can cause environmental pollution and insecticide resistance. Therefore, the search for eco-friendly and effective mosquito control agents has led to the exploration of plant extracts with larvicidal efficacy. In this study, we aimed to explore the larvicidal activity of four Egyptian plant extracts: Rosmarinus officinalis, Melissa officinalis, Cichorium intybus, and Beta vulgaris var. cicla against Culex pipiens and to identify the chemical constituents present in the active extracts. The methanolic extracts of the four plants were prepared and tested against the third instar larvae of C. pipiens using a standard method. The lethal concentrations (LC50 and LC90) were calculated using probit analysis. The active extracts were subjected to ultra-performance liquid chromatography-mass spectroscopy (UPLC-MS/MS) analysis and the data were processed using the global natural products social molecular networking (GNPS) platform to generate molecular networks and identify the compounds based on spectral similarity and database matching. The methanolic extracts of R. officinalis L. and M. officinalis L. had the highest larvicidal activity, where LC50 values were 9.795 and 26.505 μg/mL, respectively. Their exposure caused a high mortality rate and disrupted the biochemical and physiological parameters (total carbohydrates, total lipids, total protein, acetylcholinesterase (AChE), and glutathione S-transferase (GST) in the body of C. pipiens when compared with Cichorium intybus (Chicory) and Beta vulgaris var. cicla (Chard). The UPLC-MS/MS analysis with the aid of the GNPS platform, revealed the presence of 23 and 41 metabolites from R. officinalis L. and M. officinalis L., respectively. The identified metabolites may act as larvicidal agents by interfering with the physiological or biochemical processes of the mosquito larvae. Overall, the findings suggest that the methanolic extracts of R. officinalis and M. officinalis are potential sources of natural larvicides for mosquito control.

Exploration of Developmental Variants of Predatory Ladybird, Coccinella septumpunctata L. (Coleoptera: Coccinellidae) on an Artificial Diet.

This study aimed to focus on the identification, rearing, and exploration of developmental variants of the predatory ladybird, Coccinella septempunctata L., renowned for its efficacy as a biological control agent and its predation on agricultural pests. However, comprehensive knowledge concerning the occurrence and characteristics of developmental variants in this species remains limited. In this study, through meticulous monitoring and exploration, we identified developmental variants exhibiting distinct sexual attributes, as well as survival rates. The research outcomes enhance our understanding of the developmental variations within an egg batch of C. septempunctata. Moreover, the findings hold practical implications for the implementation of biological control strategies in agriculture, as specific variants may possess unique characteristics that enhance their effectiveness as natural enemies against pests.

Entomopathogenic Bacillus cereus impairs the fitness of the spotted-wing drosophila, Drosophila suzukii.

Drosophila suzukii is a notorious pest which causes devastating damage to thin-skinned fruits, and the larvae feed on the fruit, causing extensive agricultural economic loss. The current application of insecticides to manage this pest results in serious resistance and environmental hazards, so an alternative strategy for D. suzukii biocontrol is urgently needed. Here, we reported that entomopathogenic Bacillus cereus has the potential to biocontrol D. suzukii. We isolated and identified the bacterial strain, B. cereus H1, that was detrimental to the fitness of both D. suzukii progenies and parents. D. suzukii was robustly repelled to depositing eggs on the halves with metabolites of B. cereus H1. Both males and females of D. suzukii were susceptible to B. cereus H1. B. cereus H1 significantly arrested larval development with at least 40% lethal larvae. The median lethal time (LT50) of males and females of D. suzukii challenged with B. cereus H1 was 3 and 2d, respectively. Moreover, B. cereus H1 disrupted the intestinal integrity and pH value of D. suzukii and resulted in an increase in bacterial load of guts and hemolymph. Mechanistically, infection of B. cereus H1 led to the activation of the dual oxidase (DUOX)-ROS-Jun N-terminal kinase (JNK) pathway. The findings showed that the entomopathogen B. cereus H1 could potentially act as a biological control agent against D. suzukii, advancing fundamental concepts of integrated pest management programs against D. suzukii.

Inhibition of Aspergillus spp. growth and ochratoxin A production in Conilon and Arabica coffees based-medium by Saccharomyces cerevisiae

Saccharomyces cerevisiae CCMA 0159 is reported as a promising biocontrol agent against ochratoxin A (OTA)-producing fungi in coffee. Coffea arabica and Coffea canephora (var. Conilon or Robusta) are the most widely consumed coffee species around the world, cultivated in tropical and subtropical regions, each exhibiting distinct physicochemical and sensory characteristics. The objective of this study was to compare the growth and OTA production by Aspergillus carbonarius, A. ochraceus, and A. westerdijkiae in C. arabica and C. canephora, along with assessing the efficiency of S. cerevisiae CCMA 0159 in biocontrolling ochratoxigenic fungi in both coffee varieties. A. carbonarius exhibited a higher growth rate and OTA production in both coffee varieties, with C. canephora showing particular susceptibility. Conversely, A. ochraceus and A. westerdijkiae demonstrated lower growth and OTA production. S. cerevisiae was effective in biocontrolling the fungal isolates, inhibiting over 80 % of A. carbonarius growth in both coffee varieties. Among the mechanisms of action of the biological control agent, the production of volatile organic compounds stands out. The results of this study confirm the significant potential of S. cerevisiae CCMA 0159 as a biocontrol agent against Aspergillus for application in coffee-producing areas.

Molecular characterization and gene expression of pattern recognition receptors in brown-marbled grouper (Epinephelus fuscoguttatus) fingerlings responding to vibriosis infection

The pathogen recognition system involves receptors and genes that play a crucial role in activating innate immune response in brown-marbled grouper (Epinephelus fuscoguttatus) as a control agent against various infections including vibriosis. Here, we report the molecular cloning of partial open reading frames, sequences characterization, and expression profiles of Pattern Recognition Receptors (PRRs) in brown-marbled grouper. The PRRs, namely pglyrp5, tlr5, ctlD, and ctlE in brown-marbled grouper, possess conserved domains and showed shared evolutionary relationships with other fishes, humans, mammals, birds, reptilians, amphibians, and insects. In infection experiments, up to 50% mortality was found in brown-marbled grouper fingerlings infected with Vibrio alginolyticus compared to 27% mortality infected Vibrio parahaemolyticus and 100% survival of control groups. It is also demonstrated that all four PRRs had higher expression in samples infected with V. alginolyticus compared to V. parahaemolyticus. This PRRs gene expression analysis revealed that all four PRRs expressed rapidly at 4-h post-inoculation even though the Vibrio count was only detected earliest at 12-h post-inoculation in samples. The highest expression recorded was from V. alginolyticus inoculated fish spleen with up to 73-fold change for pglyrp5 gene, followed by 14 to 38-fold expression for the same treatment in spleen, head kidney, and blood samples for other PRRs, namely tlr5, ctlD, and ctlE genes. Meanwhile less than a 10% increase in expression of all four genes was detected in spleen, head kidney, and blood samples inoculated with V. parahaemolyticus. These findings indicated that pglyrp5, tlr5, ctlD, and ctlE play important roles in the early immune response to vibriosis infected, brown-marbled grouper fingerlings.

Bacillus velezensis Y6, a Potential and Efficient Biocontrol Agent in Control of Rice Sheath Blight Caused by Rhizoctonia solani.

Rice sheath blight is a serious disease caused by Rhizoctonia solani that reduces rice yield. Currently, there is a lack of efficient and environmentally friendly control methods. In this study, we found that Bacillus velezensis (B. velezensis) Y6 could significantly inhibit the growth of mycelium in Rhizoctonia solani, and its control efficiency against rice sheath blight was 58.67% (p < 0.01) in a pot experiment. Lipopeptides play an important role in the control of rice sheath blight by B. velezensis Y6, among which iturin and fengycin are essential, and iturin W, a novel lipopeptide in B. velezensis, plays a major role in lipopeptide antagonism to Rhizoctonia solani. In the field, we also found that inoculation with B. velezensis Y6 can increase rice yield (dry weight) by 11.75%. Furthermore, the transcriptome profiling results of the rice roots revealed that there were a total of 1227 differential genes (DEGs) regulated when treated with Y6, of which 468 genes were up-regulated and 971 genes were down-regulated in rice roots compared with the control. Among them, the DEGs were mainly distributed in biological processes (BP) and were mainly enriched in response to stimulus (GO:0050896), response to stress (GO:0006950), and response to abiotic stimulus (GO:0009628). According to the KEGG pathway analysis, there were 338 DEGs classified into 87 KEGG functional pathway categories. Compared with the control, a large number of enriched genes were distributed in phenylpropanoid biosynthesis (map00940), glutathione metabolism (map00480), glycolysis/gluconeogenesis (map00010), and amino sugar and nucleotide sugar metabolism (map00520). In summary, this investigation provides a new perspective for studying the molecular mechanism of B. velezensis in controlling rice sheath blight.

Efeito nematicida do fungo Duddingtonia flagrans em ovinos

The health of the sheep flock depends, among other factors, on effective sanitary control, and the use of fungus-based bioproducts has been a promising alternative against sheep gastrointestinal nematodes. The control of ovine gastrointestinal diseases caused by parasites requires good management practices that minimize the exposure of animals to the infective larvae of parasites present in the environment. The fungus Duddingtonia flagrans is an efficient agent for the biological control of nematodes due to its efficiency in controlling parasites in domestic animals. The aim of this literature review is to demonstrate the predatory activity of the fungus Duddingtonia flagrans against infective larvae (L) of gastrointestinal nematodes in ruminant sheep. The fungus in the form of D. flagrans chlamydospores proved to be resistant to the digestive process of ruminants and efficient against intestinal parasites. Its use in association with anthelmintics proved to be a good alternative for biological control. This possibility of using bioproducts and anthelmintics in combination reduces the effects of parasite resistance. Various methods of delivering the fungus orally, in pellets or powder, have obtained results that prove the efficacy of D. flagrans isolates in reducing infective nematode larvae.

Toxicological and physiological activity of lemongrass and peppermint essential oils as acaricidal agents on life-table parameters of Oligonychus mangiferus (Rahman & Sapra) and its predatory mite, Cydnoseius negevi (Swirskii & Amitai)

The goal of this study is to explore the effects of lemongrass and peppermint essential oils, specifically at their LC50 concentrations, on the demographic parameters of two mite species: Oligonychus mangiferus (Rahman & Sapra) and its predatory mite counterpart, Cydnoseius negevi (Swirskii & Amitai). By evaluating these essential oils, the study aims to contribute to eco-friendly pest management strategies within integrated pest management (IPM) programs. The effects of these oils were assessed in terms of measuring the activity of antioxidant and detoxifying enzymes. GC–MS was used to identify the chemical components of these oils. The main compounds identified by GC–MS in lemongrass and peppermint essential oils were D-Limonene (45.06%), β-Citral (10.30%), α-Citral (9.90%)) and (Menthol (32.03%), Menthone (30.18%), p-Menthan-3-one (11.53%), respectively. The results showed that lemongrass and peppermint were more toxic to O. mangiferus than to C. negevi. Exposure of O. mangiferus to the LC50 of these oils caused a significant increase in peroxidase and catalase enzymes, but it inhibited the detoxifying enzymes, α-esterase, β-esterase, and glutathione s-transferase. Also, these oils had disruptive effects on survival, longevity, and fecundity of O. mangiferus; as they reduced its demographic parameters such as (R0) (GRR) (rm), and (λ). However, they did not show any substantial change in the development time and demographic parameters of C. negevi. On the contrary, they improved its enzymes activity. According to these findings, these essential oils can be used in combination with biological control agents in the integrated pest management strategies against the mango spider mite, O. mangiferus.

Biocontrol potential of Bacillus velezensis QF-2 isolated from rhizosphere soil of Vickifunkia tianschanica

Plant diseases caused by pathogenic fungi result in substantial losses of human, material, and financial resources annually. The common practice of chemical control often leads to the development of drug resistance in target organisms and carries adverse environmental impacts. As an alternative, researchers are exploring the potential of microbial control agents found in the rhizosphere.Previous studies have identified numerous promising microbial strains that could be utilized as effective, ecologically-friendly, and sustainable solutions to manage plant diseases. In the present investigation, a bacterial strain designated QF-2 was isolated from the rhizosphere soil of Vickifunkia tianschanica. Through dual culture experiments and molecular biological analysis, the taxonomic status of this strain was clearly established, and its antagonistic activities against seven plant pathogens were observed. Furthermore, the researchers conducted a comprehensive analysis of the QF-2 genome. Concurrently, five secondary metabolites (1–5) produced by QF-2 were studied, isolated, and identified.

Composition of Parasitoid Wasps in Insect Pests of Rice (Rice Leaffolder, Cnaphalocrocis Medinalis Guenée)

Biological control is one aspect of Integrated Pest Management (IPM). The method focusses on natural enemies; beneficial insects are applied for biological control of agricultural insect pests and also provide an environmentally friendly approach. For the rice pests including Rice Leaf Folder (RLF), several parasitoids tend to be natural enemies that could be used to control the pest from the egg stage to pupa. This study was conducted with two varieties of rice, namely “Sen Kra Oub” and “Sro Ngea” at Battambang Province of Cambodia. Parasitoid wasps were collected from egg to pupa stages of RLF and rice yellow stem borer by rearing method, and stored in 70% of alcohol solution before sending for identification in Vietnam’s Institute of Ecology and Biological Resources (IEBR) Laboratory. The outcomes revealed that five hymenopteran parasitic wasps of three different families were found, viz. Apanteles cypris Nixon, Bracon onukii Watanabe and Pentatermus striatus (Szepligeti) (Braconidae), Xanthopimla flavolineata Cameron (Ichneumonidae), and Telenomus rowani Gahan (Scelionidae) and being the primary parasitoids of rice leaffolder, Cnaphalocrocis medinalis Guenee; stemborer Scirpophaga incertulas Walker (Pyralidae) and black branded swift Pelopidas mathias (Hesperiidae). Parasitism was not found at the vegetative phase with Sen Kra Ob varieties but in reproductive phase. parasitism proportion was 16.66% and 28.57% to 50% in ripening phase, different from Sro Ngea variety where a proportion was found in vegetative phase 27.27%, reproductive phase at 28.57% to 40% and 28.57% to 43% in ripening phase. All the hymenopteran parasitoids were initially recorded in Cambodia, whereby all the parasitoids were potential agents for biological control for important rice insect pests. The outcome of this research suggests that the Government should invest more in the research and development for biological control in Cambodia.

Practical Suggestions for Assessing Rabbit Haemorrhagic Disease Virus 2 Risk to Endangered Native Lagomorphs in North America and Southern Africa.

A new form of the rabbit haemorrhagic disease virus, RHDV2, first observed in European rabbits, has spread widely among different species of hares in Europe, jackrabbits and cottontails in North America, and hares in southern Africa. However, only limited surveillance studies have been undertaken so far. It is suggested that methods developed for controlling the disease in farmed rabbits in Europe and studying the efficacy of RHDV as a biological control agent in Australia could facilitate epidemiological research on those recently affected lagomorph species. This would enable the assessment of the risk of RHDV2 to native lagomorphs, including endangered species, and the determination of the main host species of RHDV2. Because RHDV2 has not spread equally through all lagomorph species, epidemiological studies could give insights into factors important for determining host susceptibility.

Antagonistic Strain Bacillus velezensis JZ Mediates the Biocontrol of Bacillus altitudinis m-1, a Cause of Leaf Spot Disease in Strawberry.

Biofertilizers are environmentally friendly compounds that can enhance plant growth and substitute for chemically synthesized products. In this research, a new strain of the bacterium Bacillus velezensis, designated JZ, was isolated from the roots of strawberry plants and exhibited potent antagonistic properties against Bacillus altitudinis m-1, a pathogen responsible for leaf spot disease in strawberry. The fermentation broth of JZ exerted an inhibition rate of 47.43% against this pathogen. Using an optimized acid precipitation method, crude extracts of lipopeptides from the JZ fermentation broth were obtained. The crude extract of B. velezensis JZ fermentation broth did not significantly disrupt the cell permeability of B. altitudinis m-1, whereas it notably reduced the Ca2+-ATPase activity on the cell membrane and markedly elevated the intracellular reactive oxygen species (ROS) concentration. To identify the active compounds within the crude extract, QTOF-MS/MS was employed, revealing four antimicrobial compounds: fengycin, iturin, surfactin, and a polyene antibiotic known as bacillaene. The strain JZ also produced various plant-growth-promoting substances, such as protease, IAA, and siderophore, which assists plants to survive under pathogen infection. These findings suggest that the JZ strain holds significant potential as a biological control agent against B. altitudinis, providing a promising avenue for the management of plant bacterial disease.

Long-term post-release evaluation shows Hypogeococcus sp. is an effective biological control agent for queen of the night cactus in South Africa

ABSTRACT We conducted long-term monitoring of Hypogeococcus sp. (Pseudococcidae) as a biocontrol agent for queen of the night cactus (Cereus jamacaru De Candolle). The biocontrol agent was released at three sites representing the regions where the plant is problematic in South Africa, and both agent and plant populations were monitored over time. The proportion of plants producing fruits or flowers decreased by 36% each year, with all plants no longer flowering between two and seven years after release. Plant density reduced by 42% each year after release. Hypogeococcus sp. is an effective agent against C. jamacaru in South Africa.