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In this study, we aimed to screen potential antagonistic microorganisms against Erwinia amylovora , the causal agent of fire blight. From 127 unknown bacterial isolates tested, 2 bacterial strains (BCA3 and BCA19) were identified to show distinct antagonistic activity against E. amylovora in agar plate assay. Phylogenetic analysis of the 16s rRNA sequence identified both BCA3 and BCA19 as Pantoea ananatis. Among these BCA19 showed 13.9% stronger antagonistic activity than BCA3. Thus we further characterized antagonistic activity of BCA19. Culture filtrates (CF) of BCA19 significantly inhibited the swimming and swarming motility of E. amylovora. Ethyl acetate and n-butanol extracts of CF of BCA19 exhibited antibacterial activity in disk diffusion assay. Furthermore, gas chromatography–mass spectrometry analysis of ethyl acetate and n-butanol extracts of CF of BCA19 identified antibacterial compounds, including indole and hexahydropyrrolo[1,2-a]pyrazine-1,4-dione. Importantly, indole inhibited growth of E. amylovora with IC50 value of 0.109 ± 0.02 mg/mL (~930.4 μM). Whole genome sequence analysis of BCA 19 revealed gene clusters related with siderphore, andrimid, arylpolyene and carotenoid-type terpene production. This study indicates that BCA19 can be used as a potential biological control agent against Erwinia amylovora. [ABSTRACT FROM AUTHOR]

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.

Endophytic fungi are microorganisms known as plant-associated fungi and are typically found asymptomatically inside plant tissue. By directly generating secondary metabolites, endophytic fungi help their host plants grow and become more resistant to plant diseases. Furthermore, they can also biosynthesize bioactive compounds used for antimicrobials, which were previously believed to be produced only by the host plant. Medicinal plants as host plants for endophytic fungi which produce secondary metabolites and their ability as biological agents against pathogens. Calabash tree is a medicinal plant that contains active compounds that function as antifungal and antibacterial. This study aims to determine the antagonistic activity of endophytic fungi from calabash tree leaves against F. oxysporum Fos, the pathogen that causes fusarium wilt in shallot plants. Twelve endophytic fungi were obtained from isolation from the leaves of the calabash tree, namely EnM6C22, EnM11P2, EnM6A2, EnM5H21, EnM10H22, EnM12P, EnM11P, EnM111, EnM5H22, EnM9Pt22, EnM5H1 and EnM5K. Five of the twelve endophytic fungi of calabash tree leaves have been identified, as Fusarium sp., Rhizoctonia sp., Pestalotia sp., Colletotrichum sp., and Bipolaris sp. with inhibition percentages of 36.43%, 32.19%, 25.41%, 32.19%, and 27.53% respectively at 7 days after inoculation.

Abstract Purpose Rot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. Methods The disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. Results The findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. Conclusion These findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development.

This study was designed to investigate the acute toxicity (mortality) and sublethal effects (fertility and potential natality) of carlina oxide, the main constituent of Carlina acaulis essential oil (EO), against adults of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae). Moreover, its toxicity was evaluated against two aphid natural enemies, i.e., Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) and Chrysoperla carnea Stephens (Neuroptera: Chrysopidae). The highest tested concentration (3.0 mL L−1) resulted in 96.7% mortality of adults of the target pest, highlighting that this concentration of carlina oxide had a similar effectiveness as the positive control we used. Furthermore, probit analysis allowed the estimation of a LC50 of 1.06 mL L−1 and a LC90 of 2.58 mL L−1 for the target pest, which resulted in a much higher mortality rate than that found on natural enemies, i.e., A. aphidimyza (6.7 ± 4.7% ± SD when exposed to the aphid LC90) and C. carnea (7.0 ± 5.5% ± SD when exposed to the aphid LC90), showing the limited non-target impact of carlina oxide. The use of LC30 and LC50 of this compound allowed the fertility inhibition of the target pest by 35.68 ± 6.21% and 23.66 ± 10.58%, respectively, and potential natality inhibition of the target pest by 52.78 ± 4.48% and 59.69 ± 5.60%, respectively. Of note, carlina oxide showed excellent insecticidal activity against M. dirhodum, comparable to the commercial insecticide considered. Overall, the low toxicity of carlina oxide toward A. aphidimyza and C. carnea makes it a safe compound for non-target organisms as well as suitable for developing a green insecticide for the management of M. dirhodum and perhaps other insects of agricultural or medical and veterinary interest. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In February 2024, the ficus whitefly Singhiella simplex (Singh, 1931) (Hemiptera: Aleyrodidae) was first reported in a tropical greenhouse and inside a private house in Northern Italy (Vertemate con Minoprio and Monza, respectively – Lombardy Region). The observed ficus whiteflies caused severe defoliation on different Ficus species including Ficus benjamina and Ficus retusa. Several third and fourth larval instars of Singhiella simplex were associated with the parasitoid wasp Encarsia hispida De Santis, 1948 (Hymenoptera: Aphelinidae). Morphological and molecular analyses were performed to identify both S. simplex and E. hispida. Based on current knowledge, this is the first report of the ficus whitefly in Northern Italy as well as the first observation of its association with the parasitoid wasp E. hispida in Europe. [ABSTRACT FROM AUTHOR]

Purpose: Rot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. Methods: The disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. Results: The findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. Conclusion: These findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development. [ABSTRACT FROM AUTHOR]

Tadpole shrimp (Triops longicaudatus) has become a major pest for California rice farmers. Currently, management relies solely on the insecticide lambda-cyhalothrin. However, resistance to this pyrethroid was confirmed in 2016; thus, identifying an effective and practical biological control method for TPS is a priority. Field trials were conducted from 2017 to 2018 to (1) evaluate the efficacy of the predatory fish Gambusia affinis and the predatory beetles, Laccophilus maculosus (Say) and Tropisternus lateralis (Fabricius), in controlling TPS, (2) test the efficacy of several inoculation rates of Gambusia affinis at controlling TPS and (3) to explore early indicators of TPS activity and damage as monitoring tools. Both Gambusia affinis and the predatory beetle treatments were not significantly different from the commercial standard (lambda-cyhalothrin). Both four and five Gambusia per 1 m2 controlled TPS as well as lambda-cyhalothrin, and we observed that Gambusia affinis was able to reproduce in the field. Water turbidity was significantly correlated with TPS counts (R = 0.85, N = 20, p < 0.0001 (2017); R = 0.58, N = 30, p = 0.0007 (2018)). The number of dislodged seedlings was less reliably correlated with TPS count; in 2017, correlations were significant (R = 0.84, N = 20, p < 0.0001); however, in 2018, correlations were not significant (R = 0.18, N = 30, p = 0.35). With further refinement, water turbidity could play a valuable role in monitoring TPS populations. [ABSTRACT FROM AUTHOR]

The parasitoids Microctonus aethiopoides Loan (Moroccan and Irish ecotypes) and M. hyperodae Loan (Hymenoptera: Braconidae) have been introduced to New Zealand as biological control agents for agricultural pest weevils Sitona discoideus Gyllenhal, S. obsoletus Gmelin and Listronotus bonariensis (Kuschel). These parasitoids are also present in native tussock grassland habitats and a survey carried out over two years at nine tussock grassland sites demonstrated that several endemic weevil species were parasitized by these biological control agents within these habitats. New records of non-target parasitism were found for the endemic species of Chalepistes, Nicaeana, and Eugnomus. It was found that M. aethiopoides is established and cycling within weevil communities in these environments, using endemic weevil hosts in part, but pathways also exist via three pest weevil species for spillover from agricultural environments. Parasitism of endemic weevils was not found to be ubiquitous in these environments and parasitism levels were mostly below 10%.

In this study, we aimed to screen potential antagonistic microorganisms against Erwinia amylovora, the causal agent of fire blight. From 127 unknown bacterial isolates tested, 2 bacterial strains (BCA3 and BCA19) were identified to show distinct antagonistic activity against E. amylovora in agar plate assay. Phylogenetic analysis of the 16s rRNA sequence identified both BCA3 and BCA19 as Pantoea ananatis. Among these BCA19 showed 13.9% stronger antagonistic activity than BCA3. Thus we further characterized antagonistic activity of BCA19. Culture filtrates (CF) of BCA19 significantly inhibited the swimming and swarming motility of E. amylovora. Ethyl acetate and n-butanol extracts of CF of BCA19 exhibited antibacterial activity in disk diffusion assay. Furthermore, gas chromatography–mass spectrometry analysis of ethyl acetate and n-butanol extracts of CF of BCA19 identified antibacterial compounds, including indole and hexahydropyrrolo[1,2-a]pyrazine-1,4-dione. Importantly, indole inhibited growth of E. amylovora with IC50 value of 0.109 ± 0.02 mg/mL (~930.4 μM). Whole genome sequence analysis of BCA 19 revealed gene clusters related with siderphore, andrimid, arylpolyene and carotenoid-type terpene production. This study indicates that BCA19 can be used as a potential biological control agent against Erwinia amylovora.

Cherry leaf spot (CLS) disease is one of the most common and deleterious disease of flowering cherry seedlings which lowers frost tolerance, growth, and biomass production during the season, and reduces flower production in following season. This study isolated two phytopathogens, Alternaria alternata CH3 and Alternaria alternata CH10, and confirmed their pathogenicity of CLS disease in flowering cherry seedlings, causing brownish spots and necrotic lesions on the leaves. We also isolated a plant growth-promoting bacteria (PGPB), Bacillus subtilis strain CV21, and investigated its antifungal and plant growth-promoting properties. The bacterium produced cell wall-degrading enzymes such as chitinase, β-1,3-glucanase, and protease and effectively antagonized both A. alternata CH3 and A. alternata CH10 and the crude enzyme fraction (100 µl/mL) of B. subtilis CV21 inhibited spore germination by 40.1 % and 25.1 % and reduced mycelial growth by 29.1 % and 42.5 % against A. alternata CH3 and A. alternata CH10. The crude enzyme fraction degraded the cell walls of both phytopathogens in a concentration-dependent manner, causing swelling with bulbous structures in the hyphal cell, and cell wall lysis with severe perforations, loss of shape and aggregation of spores compared to control. Treatment with the bacterial culture broth on flowering cherry seedlings reduced CLS disease by 1.3-fold and 3.4-fold compared to the chemical treatment and the control group, respectively. In addition, B. subtilis CV21 also demonstrated plant growth-promoting properties such as indole-3-acetic acid (IAA) production up to a maximum concentration of 3.5 µg/mL during the experimental period and exhibited potential for phosphate solubilization and nitrogen fixation. The inoculation of nursery seedlings with B. subtilis CV21 culture broth improved the chlorophyll content, and increased seedling growth and biomass production compared to chemical treatment and the control group. The results demonstrate that the B. subtilis CV21 could be effectively applied as a bio-fungicide to control CLS and as bio-stimulant/bio-fertilizer to enhance the growth of flowering cherry seedlings.

ABSTRACTMacro- and microscopic morphological studies and multilocus phylogenetic analysis were made on larval specimens of a ghost moth collected from a pigeon pea plantation in Huánuco, Peru. DNA sequences from the cadaver and the fungal isolates obtained represented a monophyletic clade based on the phylogeny. All morphological characters and molecular data showed that the pathogenic fungus infecting the ghost moth larvae was an unknown cordycipitoid species, herein described as, Harposporium incensis sp. nov. based on morphological features and multilocus phylogenetic analysis on the cadaver and fungus isolated from the same specimen. The far-related and ecologically different hosts of teleomorph and anamorph of this new species display a peculiar inter-phylum host jumping between the insect Trichophassus giganteus of the phylum Arthropoda and the nematode Caenorhabditis elegans of the phylum Nematoda and have biological control potential.

Erwinia amylovora is a plant pathogen that causes fire blight on apples and pears. Bacteriophages, which are viruses that selectively infect specific species of bacteria and are harmless to animal cells, have been considered as biological control agents for the prevention of bacterial pathogens. In this study, we aimed to use bacteriophages that infect E. amylovora as biocontrol agents against fire blight. We isolated bacteriophages Fifi044 and Fifi318 infecting E. amylovora, and characterized their morphology, plaque form, and genetic diversity to use as cocktails for disease control. The stabilities of the two phages were investigated at various temperatures and pH values and under sunlight, and long-term storage experiment was conducted for a year. To evaluate whether the two phages were suitable for use in cocktail form, growth curves of E. amylovora were prepared after treating the bacterial cells with single phages and a phage cocktail. In addition, a disease control test was conducted using immature apples and in vitro cultured apple plantlets to determine the biocontrol effects of the phage cocktail. The two phages were morphologically and genetically different, and highly stable up to 50°C and pH value from 4 to 10. The phages showed synergistic effect when used as a cocktail in the inhibition of host bacterial growth and the disease control. This study demonstrated that the potential of the phage cocktail as a biocontrol agent for commercial use.

Efficient and sustainable food production is crucial in global agricultural development. Overuse of chemical fertilizers leads to soil acidification, destruction of soil properties, and harm to soil micro-organisms. Plant growth-promoting rhizobacteria (PGPR) have emerged as a solution, enhancing soil fertility and crop yields while reducing chemical fertilizer dependency and disease occurrence. In this study, Bacillus strains KHC2, KHH5, and KHH13, isolated from organic rice field soils in Taiwan, were identified through molecular techniques as B. velezensis (KHC2, KHH13) and B. amyloliquefaciens (KHH5). The strains exhibited various hydrolytic enzymes (including protease, cellulase, amylase, and lecithinase), with KHH13 showing the highest phosphate solubilization (2186.1 µg mL−1 day−1) and indole-3-acetic acid (IAA) production (63.067 ± 0.595 ppm mL−1). These properties indicate KHH13's potential as a bio-enhancer for plant growth. Therefore, we hypothesized that KHH13 can enhance plant growth and control soil-borne diseases. A greenhouse experiment demonstrated that KHH13, KHC2, and KHH5 effectively promoted the growth of red lettuce, with KHH13 showing superior efficacy. The study also found KHH13's treatment enhanced the growth of various vegetables, including tomato, cucumber, and red lettuce. In terms of disease control, KHH13 significantly reduced Fusarium wilt in cucumbers, as evidenced by the reduction in disease index from 74.33% to 41.67% after KHH13 treatment. The treatment group displayed better plant growth, including plant height and fresh weight, compared to the control group in the greenhouse experiment. Furthermore, oral and pulmonary acute toxicity analysis in rats showed no adverse effects on rat weight or mortality, indicating KHH13's safety for mammalian use. These findings suggest B. velezensis KHH13 as a safe, effective, and sustainable biological agent for enhancing vegetable growth and controlling soil-borne diseases, with potential applications in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Macro- and microscopic morphological studies and multilocus phylogenetic analysis were made on larval specimens of a ghost moth collected from a pigeon pea plantation in Huánuco, Peru. DNA sequences from the cadaver and the fungal isolates obtained represented a monophyletic clade based on the phylogeny. All morphological characters and molecular data showed that the pathogenic fungus infecting the ghost moth larvae was an unknown cordycipitoid species, herein described as, Harposporium incensis sp. nov. based on morphological features and multilocus phylogenetic analysis on the cadaver and fungus isolated from the same specimen. The far-related and ecologically different hosts of teleomorph and anamorph of this new species display a peculiar inter-phylum host jumping between the insect Trichophassus giganteus of the phylum Arthropoda and the nematode Caenorhabditis elegans of the phylum Nematoda and have biological control potential. [ABSTRACT FROM AUTHOR]

Banana (Musa acuminata) is the most important crop in the Canary Islands (38.9% of the total cultivated area). The main pathogen affecting this crop is the soil fungal Fusarium oxysporum f. sp. cubense subtropical race 4 (Foc-STR4), for which there is no effective control method under field conditions. Therefore, the use of native biological control agents may be an effective and sustainable alternative. This study aims to: (i) investigate the diversity and distribution of Trichoderma species in the rhizosphere of different banana agroecosystems affected by Foc-STR4 in Tenerife (the island with the greatest bioclimatic diversity and cultivated area), (ii) develop and preserve a culture collection of native Trichoderma species, and (iii) evaluate the influence of soil chemical properties on the Trichoderma community. A total of 131 Trichoderma isolates were obtained from 84 soil samples collected from 14 farms located in different agroecosystems on the northern (cooler and wetter) and southern (warmer and drier) slopes of Tenerife. Ten Trichoderma species, including T. afroharzianum, T. asperellum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hamatum, T. harzianum, T. hirsutum, T. longibrachiatum, and T. virens, and two putative novel species, named T. aff. harzianum and T. aff. hortense, were identified based on the tef1-a sequences. Trichoderma virens (35.89% relative abundance) and T. aff. harzianum (27.48%) were the most abundant and dominant species on both slopes, while other species were observed only on one slope (north or south). Biodiversity indices (Margalef, Shannon, Simpson, and Pielou) showed that species diversity and evenness were highest in the healthy soils of the northern slope. The Spearman analysis showed significant correlations between Trichoderma species and soil chemistry parameters (mainly with phosphorus and soil pH). To the best of our knowledge, six species are reported for the first time in the Canary Islands (T. afroharzianum, T. asperellum, T. atrobrunneum, T. guizhouense, T. hamatum, T. hirsutum) and in the rhizosphere of banana soils (T. afroharzianum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hirsutum, T. virens). This study provides essential information on the diversity/distribution of native Trichoderma species for the benefit of future applications in the control of Foc-STR4. [ABSTRACT FROM AUTHOR]

Invasive fungal diseases represent a major threat to forest ecosystems worldwide. As the application of fungicides is often unfeasible and not a sustainable solution, only a few other control options are available, including biological control. In this context, the use of parasitic mycoviruses as biocontrol agents of fungal pathogens has recently gained particular attention. Since the 1990s, the Asian fungus Hymenoscyphus fraxineus has been causing lethal ash dieback across Europe. In the present study, we investigated the biocontrol potential of the mitovirus Hymenoscyphus fraxineus mitovirus 2 (HfMV2) previously identified in Japanese populations of the pathogen. HfMV2 could be successfully introduced via co-culturing into 16 of 105 HfMV2-free isolates. Infection with HfMV2 had contrasting effects on fungal growth in vitro, from cryptic to detrimental or beneficial. Virus-infected H. fraxineus isolates whose growth was reduced by HfMV2 showed overall a lower virulence on ash (Fraxinus excelsior) saplings as compared with their isogenic HfMV2-free lines. The results suggest that mycoviruses exist in the native populations of H. fraxineus in Asia that have the potential for biological control of ash dieback in Europe. [ABSTRACT FROM AUTHOR]

Radiata pine is one of the most commonly planted tree species in Chile due to its fast growth and desirable wood and pulp properties. However, its productivity is hampered by several diseases. Pitch canker disease (PCC) caused by Fusarium circinatum, is considered the most damaging disease to the pine forest industry. Several control measures have been established, with biological control emerging as an environmentally friendly and effective way for F. circinatum control. Previous studies support the value of Clonostachys rosea in reducing PCC damage, with evidence suggesting a potential induced systemic resistance (ISR) triggered in radiata pines by this agent. Ten-month-old radiata pine plants were pre-treated with C. rosea on a substrate at 8 and 1 days before inoculation with F. circinatum on the stem tip, and expression levels were determined for DXS1, LOX, PAL, and PR3 genes 24 h later. Lesion length was 45% lower on plants pre-treated with C. rosea and infected with F. circinatum compared to non-pre-treated and infected plants. Additionally, LOX and PR3 were induced 23 and 62 times more, respectively, in comparison to untreated plants. Our results indicate that C. rosea causes an ISR response in pre-treated plants, significantly increasing the expression of resistance genes and reducing lesion length. [ABSTRACT FROM AUTHOR]

This study examined the impact of Metarhizium anisopliae (Hypocreales: Clavicipitaceae) conidia on the eggs, larvae, pupae, and adults of Spodoptera frugiperda. The results showed that eggs, larvae, pupae, and adults exhibited mortality rates that were dependent on the dose. An increased amount of conidia (1.5 × 109 conidia/mL) was found to be toxic to larvae, pupae, and adults after 9 days of treatment, resulting in a 100% mortality rate in eggs, 98% in larvae, 76% in pupae, and 85% in adults. A study using earthworms as bioindicators found that after 3 days of exposure, M. anisopliae conidia did not cause any harmful effects on the earthworms. In contrast, the chemical treatment (positive control) resulted in 100% mortality at a concentration of 40 ppm. Histopathological studies showed that earthworm gut tissues treated with fungal conidia did not show significant differences compared with those of the negative control. The gut tissues of earthworms treated with monocrotophos exhibited significant damage, and notable differences were observed in the chemical treatment. The treatments with 70 and 100 µg/mL solutions of Eudrilus eugeniae epidermal mucus showed no fungal growth. An analysis of the enzymes at a biochemical level revealed a decrease in the levels of acetylcholinesterase, α‐carboxylesterase, and β‐carboxylesterase in S. frugiperda larvae after exposure to fungal conidia. This study found that M. anisopliae is effective against S. frugiperda, highlighting the potential of this entomopathogenic fungus in controlling this agricultural insect pest. [ABSTRACT FROM AUTHOR]

Simple Summary: The tomato bug is a generalist predator commonly used to control insect pests. This exotic mirid was found in 2012 in South Texas and has been established in this region. It was initially observed feeding on nymphs of the potato psyllid in tomato crops. The potato psyllid is the vector of the fastidious bacterium that causes disease in various night-shade crops, including potato zebra chip disease (ZC), with economic losses that by the mid-2000s escalated to tens of millions of dollars in the United States, Mexico, and Central America. We assessed interactions between tomato bugs and potato psyllids in three different environmental settings. First, we estimated the numeric response of tomato bugs preying on potato psyllids under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Third, we exposed tomato bugs under controlled field release conditions to the natural occurrence of potato psyllids under a reduced insecticide program. Finally, we assessed its impact on ZC disease incidence, severity in potato tubers, and potato yield. In laboratory and greenhouse experiments, tomato bug response preying resulted in the potentially beneficial effects of the predacious tomato bug reducing potato psyllid populations. Overall, the controlled release of tomato bugs under field conditions significantly reduced potato psyllid incidence in potatoes. Furthermore, the combination of tomato bugs with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of the two potato cultivars evaluated in one season. Findings from these studies indicate that tomato bugs could be effective as a biological control agent for potato psyllids in potato production. Nesidiocoris tenuis (Hemiptera: Miridae) is a generalist predator commonly used to control the whitefly Bemisia tabaci in Europe. This mirid has been found and established in South Texas, where it was initially observed feeding on nymphs of the psyllid Bactericera cockerelli (Hemiptera: Triozidae) in open tomato fields. B. cockerelli is the vector of the fastidious bacterium "Candidatus Liberibacter solanacearum" that causes diseases in several solanaceous crops, including zebra chip (ZC) disease in potatoes. There is a need to better understand how this predator impacts the control of important crop pests, such as potato psyllids. We assessed the interactions between N. tenuis and B. cockerelli in three different environmental settings. First, we estimated the numeric response of N. tenuis preying on B. cockerelli under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Then, we exposed N. tenuis under controlled field release conditions to the natural occurrence of B. cockerelli. Finally, we assessed the compatibility between the use of N. tenuis as a biological control agent in a field study and its impact on ZC disease incidence, severity in potato tubers, and potato yield. Laboratory and greenhouse experiments resulted in diverse types of functional model responses, including exponential and linear mathematical models. Our findings revealed a significant predation effect exerted by N. tenuis, resulting in a reduction of more than fourfold in the number of B. cockerelli nymphs per cage. Specifically, the nymphal population decreased from 21 ± 3.2 in the absence of N. tenuis to 5 ± 1.6 when N. tenuis was present. Furthermore, the combination of N. tenuis with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of two potato cultivars evaluated, and in one season. Findings from these studies indicate that N. tenuis could be effective as a biological control agent for B. cockerelli in potato production in South Texas. This is the first report of N. tenuis preying on immature stages of any psyllid species. [ABSTRACT FROM AUTHOR]

Monochamus alternatus is a serious wood borer of pine trees and is a widespread vector of pine wilt disease in Asia. Cyanopterus ninghais, as a biological control agent of M. alternatus found in China, is expected to be applied for management of M. alternatus in Asia through introduction or augmentative release. To examine the host range of C. ninghais and minimize potential risk to non-target hosts in the release areas, the parasitism of this wasp on 22 species of wood boring insects from pine and other forests was determined by non-choice tests. Cyanopterus ninghais parasitized Spondylis buprestoides and M. saltuarius which also infested trees in Pinaceae, but the parasitism rates on these two beetles were significantly lower than its natural host, M. alternatus. Cyanopterus ninghais always preferred to parasitize M. alternatus in the choice tests. In addition, host plant selection tests revealed that C. ninghais was only attracted to Pinaceae, especially Masson Pine, Pinus massoniana. Changing the host plant species did not affect the preference of this parasitoid to the test hosts. The results suggested that C. ninghais had high host specificity for M. alternatus, and the combination of M. alternatus larvae and Masson Pine branches was the best combination for rearing this parasitoid.

Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens apple and pear production. It is mainly controlled by using antibiotics, such as streptomycin. Due to development of E. amylovora resistant strains and the excessive agricultural use of antibiotics, there is an increased awareness of the possibility of antibiotic resistance gene transfer to other microbes. Urgent development of biocontrol agents (BCAs) is needed that can be incorporated into integrated pest management programs as antibiotic alternatives. A novel phage-carrier system (PCS) that combines an antagonistic bacterium, Pantoea agglomerans, with its ability to act as a phage-carrier bacterium for Erwinia phages has been developed. The low viability of P. agglomerans cells following spray-drying (SD) has been a challenge for the industrial-scale production of this PCS. Here, an SD protocol was developed for P. agglomerans by modifying the growth medium and bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to the industrial-scale production of the BCA/PCS. The P. agglomerans viability was greater than 90% after SD and had a shelf life at 4 °C of 4 months, and reconstituted cells showed a 3 log reduction in E. amylovora counts with a pear disc assay. [ABSTRACT FROM AUTHOR]

Crop plants are vulnerable to a variety of diseases, including anthracnose, caused by various species of Colletotrichum fungi that damages major crops, including apples and hot peppers. The use of chemical fungicides for pathogen control may lead to environmental pollution and disease resistance. Therefore, we conducted this research to develop a Bacillus subtilis-based biological control agent (BCA). B. subtilis GYUN-2311 (GYUN-2311), isolated from the rhizosphere soil of an apple orchard, exhibited antagonistic activity against a total of 12 fungal pathogens, including eight Colletotrichum species. The volatile organic compounds (VOCs) and culture filtrate (CF) from GYUN-2311 displayed antifungal activity against all 12 pathogens, with 81% control efficiency against Fusarium oxysporum for VOCs and 81.4% control efficacy against Botryosphaeria dothidea for CF. CF also inhibited germination and appressorium formation in Colletotrichum siamense and C. acutatum. The CF from GYUN-2311 showed antifungal activity against all 12 pathogens in different media, particularly in LB medium. It also exhibited plant growthpromoting (PGP) activity, lytic enzyme activity, siderophore production, and the ability to solubilize insoluble phosphate. In trials on apples and hot peppers, GYUN-2311 effectively controlled disease, with 75 and 70% control efficacies against C. siamense in wounded and unwounded apples, respectively. Similarly, the control efficacy of hot pepper against C. acutatum in wounded inoculation was 72%. Combined application of GYUN-2311 and chemical suppressed hot pepper anthracnose to a larger extent than other treatments, such as chemical control, pyraclostrobin, TK®, GYUN-2311 and cross-spraying of chemical and GYUN-2311 under field conditions. The genome analysis of GYUN-2311 identified a circular chromosome comprising 4,043 predicted protein-coding sequences (CDSs) and 4,096,969 bp. B. subtilis SRCM104005 was the strain with the highest average nucleotide identity (ANI) to GYUN-2311. AntiSMASH analysis identified secondary metabolite biosynthetic genes, such as subtilomycin, bacillaene, fengycin, bacillibactin, pulcherriminic acid, subtilosin A, and bacilysin, whereas BAGEL analysis confirmed the presence of competence (ComX). Six secondary metabolite biosynthetic genes were induced during dual culture in the presence of C. siamense. These findings demonstrate the biological control potential of GYUN-2311 against apple and hot pepper anthracnose. [ABSTRACT FROM AUTHOR]

Endophytic fungi are microorganisms known as plant-associated fungi and are typically found asymptomatically inside plant tissue. By directly generating secondary metabolites, endophytic fungi help their host plants grow and become more resistant to plant diseases. Furthermore, they can also biosynthesize bioactive compounds used for antimicrobials, which were previously believed to be produced only by the host plant. Medicinal plants as host plants for endophytic fungi which produce secondary metabolites and their ability as biological agents against pathogens. Calabash tree is a medicinal plant that contains active compounds that function as antifungal and antibacterial. This study aims to determine the antagonistic activity of endophytic fungi from calabash tree leaves against F. oxysporum Fos, the pathogen that causes fusarium wilt in shallot plants. Twelve endophytic fungi were obtained from isolation from the leaves of the calabash tree, namely EnM6C22, EnM11P2, EnM6A2, EnM5H21, EnM10H22, EnM12P, EnM11P, EnM111, EnM5H22, EnM9Pt22, EnM5H1 and EnM5K. Five of the twelve endophytic fungi of calabash tree leaves have been identified, as Fusarium sp., Rhizoctonia sp., Pestalotia sp., Colletotrichum sp., and Bipolaris sp. with inhibition percentages of 36.43%, 32.19%, 25.41%, 32.19%, and 27.53% respectively at 7 days after inoculation. [ABSTRACT FROM AUTHOR]

We model the spatiotemporal dynamics of a community consisting of competing weed and cultivated plant species and a population of specialized phytophagous insects used as the weed biocontrol agent. The model is formulated as a PDE system of taxis–diffusion–reaction type and computer-implemented for one-dimensional and two-dimensional cases of spatial habitat for the Neumann zero-flux boundary condition. In order to discretize the original continuous system, we applied the method of lines. The obtained system of ODEs is integrated using the Runge–Kutta method with a variable time step and control of the integration accuracy. The numerical simulations provide insights into the mechanism of formation of solitary population waves (SPWs) of the phytophage, revealing the factors that determine the efficacy of combined application of the phytophagous insect (classical biological method) and cultivated plant (phytocenotic method) to suppress weed foci. In particular, the presented results illustrate the stabilizing action of cultivated plants, which fix the SPW effect by occupying the free area behind the wave front so that the weed remains suppressed in the absence of a phytophage. [ABSTRACT FROM AUTHOR]

Root-knot nematodes (RKNs) can result in severe losses to crop production and economies. Virgibacillus dokdonensis MCCC 1A00493, a deep-sea bacterium, has demonstrated potent antagonistic effects against Meloidogyne incognita in vitro. However, the control efficacy under greenhouse and field conditions remains unclear. In this study, we investigated the nematicidal effect of MCCC 1A00493 fermentation liquid and its synergism with black soldier fly (BSF) larval frass organic fertilizer both in greenhouse and field experiments. MCCC 1A00493 fermentation liquid demonstrated a significant control efficacy on RKNs both in greenhouse and field experiments, with the highest control efficacy reaching 68.97 % and 74.87 %, respectively. Meanwhile, the synergistic effects of MCCC 1A00493 and BSF larvae frass organic fertilizer was investigated by adding 10 % suspension (1 × 109 CFU/mL) of MCCC 1A00493 into 71.51 kg of chicken manure organic fertilizer produced by co-conversion of BSF larvae and Bacillus subtilis BSF-CL. It was noted that MCCC 1A00493 microbial organic fertilizer reduced disease incidence of RKNs significantly both in greenhouse and field experiments, with the root gall index decreasing by 51.75 % and 63.22 %, respectively. MCCC 1A00493 fermentation liquid and microbial organic fertilizer demonstrated a control efficacy on RKNs exceeded commercial nematicide avermectin and commercial bio-organic fertilizer, respectively. In addition, MCCC 1A00493 fermentation liquid and microbial organic fertilizer had positive effects on the growth of tomato plants. These findings confirmed that V.dokdonensis MCCC 1A00493 as a biological control agent and microbial organic fertilizer have significant effect on RKNs and can be used as potential biocontrol preparations.

Tadpole shrimp (Triops longicaudatus) has become a major pest for California rice farmers. Currently, management relies solely on the insecticide lambda-cyhalothrin. However, resistance to this pyrethroid was confirmed in 2016; thus, identifying an effective and practical biological control method for TPS is a priority. Field trials were conducted from 2017 to 2018 to (1) evaluate the efficacy of the predatory fish Gambusia affinis and the predatory beetles, Laccophilus maculosus (Say) and Tropisternus lateralis (Fabricius), in controlling TPS, (2) test the efficacy of several inoculation rates of Gambusia affinis at controlling TPS and (3) to explore early indicators of TPS activity and damage as monitoring tools. Both Gambusia affinis and the predatory beetle treatments were not significantly different from the commercial standard (lambda-cyhalothrin). Both four and five Gambusia per 1 m2 controlled TPS as well as lambda-cyhalothrin, and we observed that Gambusia affinis was able to reproduce in the field. Water turbidity was significantly correlated with TPS counts (R = 0.85, N = 20, p < 0.0001 (2017); R = 0.58, N = 30, p = 0.0007 (2018)). The number of dislodged seedlings was less reliably correlated with TPS count; in 2017, correlations were significant (R = 0.84, N = 20, p < 0.0001); however, in 2018, correlations were not significant (R = 0.18, N = 30, p = 0.35). With further refinement, water turbidity could play a valuable role in monitoring TPS populations.

The ecological fitness of the biological control strains Bacillus velezensis A17 and Lactiplantibacillus plantarum PM411 was evaluated in different crops, geographical zones, and growing seasons. Both strains (2 g L−1 of dried formulation) were spray-inoculated on apricot trees, peach trees, and grapevines. Depending on the crop, flowers, fruits, and leaves were picked at several sampling time points. The population dynamics of viable, viable but non-culturable, and dead cells were studied by comparing viability qPCR (v-qPCR), qPCR, and plate counting estimations. A17 showed high survival rates in apricot, peach, and grapevine organs. The A17 viability was confirmed since qPCR and v-qPCR estimations did not significantly differ and were rather constant after field applications. However, higher population levels were estimated by plate counting due to the non-selective characteristics of the medium used. The viability of PM411 was constrained by plant organ, crop, and climate conditions, being higher in apricot than in grapevine. PM411 survival declined after field application, indicating difficulties in its establishment. The PM411 population level was made up of dead, culturable, and viable but non-culturable cells since significant differences between the three methods were observed. In conclusion, A17 and PM411 differ strongly in their survival in grapevine, peach, and apricot.

Continuous cropping is the primary cultivation method in Chinese facility agriculture, and the challenge of it stands as a global issue in soil remediation. Growing tomatoes continuously on the same plot for an extended period can result in outbreaks of tomato bacterial wilt. It is caused by the soil-borne bacterium Ralstonia solanacearum, a widespread plant pathogen that inflicts considerable damage on economically significant crops worldwide. Simultaneously, this plant pathogen proves extremely resilient, as it can adhere to plant residues and persist through the winter, continuing to infect plants in subsequent years. Scientists have dedicated considerable efforts towards finding effective methods to manage this disease. This article delineates the characteristics of tomato bacterial wilt and the various types of pathogenic bacteria involved. It systematically reviews the progress in research aimed at controlling tomato bacterial wilt, encompassing both physical and biological aspects concerning soil and plants. Emphasis is placed on the principles and current applications of these control measures, alongside proposed improvements to address their limitations. It is anticipated that the future of tomato bacterial wilt control will revolve around the development of a novel environmental protection system and efficient control strategies, focusing on microecological management and enhancing tomato resistance against bacterial wilt through breeding. [ABSTRACT FROM AUTHOR]

Penicillium rubens strain 212 (PO212) is an effective inducer of resistance mechanisms in tomato plants against Fusarium oxysporum f.sp. lycopersici. During the interaction of PO212 with the plant, different classes of molecules may act as elicitors such as certain secreted endo-xylanases. The aim of this work was to elucidate the possible role of the xylanolytic system of PO212 in its biocontrol activity. We identified potential genes coding for xylanases (xlnA, xlnE, xylP), β-xylosidase (xlnD) and their transcriptional regulators (xlnR and araR) in PO212, and evaluated their transcriptional patterns in response to tomato root extracts or synthetic medium containing xylan as main carbon source. For this work we compared data from biocontrol strain PO212 with those of two strains of Penicillium, P. rubens S27, and P. chrysogenum IPLA33001, lacking the biocontrol efficacy. Time-course experiments showed the effect of these carbon sources on the expression rates of xylanase genes. To achieve a strong reduction in expression of xylanolytic genes, we generated a null allele of XlnR, as the specific regulator of the xylanase pathway. Absence of XlnR function prevented growth of PO212 on media containing xylan as main carbon source and consequently, expression levels of xylanases were downregulated. The relationship of the xlnR gene regulated pathway to the efficacy of PO212 as a biological control agent was evaluated. Null xlnR strains did not reduce either disease severity or incidence as wild-type PO212 does. Thus, there is a relationship between a correct expression of xylanolytic system and the capability of these enzymes as effective elicitors to trigger of plant defense systems in tomato plants against F. oxysporum f.sp. lycopersici. [ABSTRACT FROM AUTHOR]

Pistia stratiotes L. is an invasive floating plant that alters native habitats in Florida by forming thick mats that shade out submerged vegetation and obstruct navigation. Multiple genotypes of this plant have been identified from locations across its native and adventive ranges including types from throughout the Americas, the Caribbean, Asia, and Australia. We investigated the performance of a known monophagous insect, Lepidelphax pistiae, on nine P. stratiotes haplotypes (from four clades) in no-choice experiments and found that while L. pistiae performance varied on different haplotypes, there was considerable overlap in fitness and impact among haplotypes. Lepidelphax pistiae did not distinguish between purported 'native' and 'non-native' haplotypes and did not perform better or cause more damage to South American haplotypes specifically, which would have supported its utility as a biocontrol agent on the exotic haplotypes found in Florida. While L. pistiae is monophagous on P. stratiotes, it was not specific enough to differentiate consistently among the tested haplotypes and thus, may not be suitable as a biological control agent because of the potential threat they pose to native haplotypes of P. stratiotes in Florida. [ABSTRACT FROM AUTHOR]

The physics of fluid laminar flow through an idealised deutosternum assembly is used for the first time to review predatory feeding designs over 72 different-sized example species from 16 mesostigmatid families in order to inform the finding of new biological control agents. Gnathosomal data are digitised from published sources. Relevant gnathosomal macro- and micro-features are compared and contrasted in detail which may subtly impact the control of channel- or 'pipe'-based transport of prey liquids around various gnathosomal locations. Relative deutosternal groove width on the mesostigmatid subcapitulum is important but appears unrelated to the closing velocity ratio of the moveable digit. Big mites are adapted for handling large and watery prey. The repeated regular distance between deutosternal transverse ridges ('Querleisten') supports the idea of them enabling a regular fluctuating bulging or pulsing droplet-based fluid wave 'sticking' and 'slipping' along the groove. Phytoseiids are an outlier functional group with a low deutosternal pipe flow per body size designed for slot-like microchannel transport in low volume fluid threads arising from daintily nibbling nearby prey klinorhynchidly. Deutosternal groove denticles are orientated topographically in order to synergise flow and possible mixing of coxal gland-derived droplets and circumcapitular reservoir fluids across the venter of the gnathosomal base back via the hypostome to the prey being masticated by the chelicerae. As well as working with the tritosternum to mechanically clean the deutosternum, denticles may suppress fluid drag. Shallow grooves may support edge-crawling viscous flow. Lateral features may facilitate handling unusual amounts of fluid arising from opportunistic feeding on atypical prey. Various conjectures for confirmatory follow-up are highlighted. Suggestions as to how to triage non-uropodoid species as candidate plant pest control agents are included. [ABSTRACT FROM AUTHOR]

Efficient and sustainable food production is crucial in global agricultural development. Overuse of chemical fertilizers leads to soil acidification, destruction of soil properties, and harm to soil micro-organisms. Plant growth-promoting rhizobacteria (PGPR) have emerged as a solution, enhancing soil fertility and crop yields while reducing chemical fertilizer dependency and disease occurrence. In this study, Bacillus strains KHC2, KHH5, and KHH13, isolated from organic rice field soils in Taiwan, were identified through molecular techniques as B. velezensis (KHC2, KHH13) and B. amyloliquefaciens (KHH5). The strains exhibited various hydrolytic enzymes (including protease, cellulase, amylase, and lecithinase), with KHH13 showing the highest phosphate solubilization (2186.1 µg mL−1 day−1) and indole-3-acetic acid (IAA) production (63.067 ± 0.595 ppm mL−1). These properties indicate KHH13’s potential as a bio-enhancer for plant growth. Therefore, we hypothesized that KHH13 can enhance plant growth and control soil-borne diseases. A greenhouse experiment demonstrated that KHH13, KHC2, and KHH5 effectively promoted the growth of red lettuce, with KHH13 showing superior efficacy. The study also found KHH13’s treatment enhanced the growth of various vegetables, including tomato, cucumber, and red lettuce. In terms of disease control, KHH13 significantly reduced Fusarium wilt in cucumbers, as evidenced by the reduction in disease index from 74.33% to 41.67% after KHH13 treatment. The treatment group displayed better plant growth, including plant height and fresh weight, compared to the control group in the greenhouse experiment. Furthermore, oral and pulmonary acute toxicity analysis in rats showed no adverse effects on rat weight or mortality, indicating KHH13’s safety for mammalian use. These findings suggest B. velezensis KHH13 as a safe, effective, and sustainable biological agent for enhancing vegetable growth and controlling soil-borne diseases, with potential applications in sustainable agriculture.

Nesidiocoris tenuis (Hemiptera: Miridae) is a generalist predator commonly used to control the whitefly Bemisia tabaci in Europe. This mirid has been found and established in South Texas, where it was initially observed feeding on nymphs of the psyllid Bactericera cockerelli (Hemiptera: Triozidae) in open tomato fields. B. cockerelli is the vector of the fastidious bacterium “Candidatus Liberibacter solanacearum” that causes diseases in several solanaceous crops, including zebra chip (ZC) disease in potatoes. There is a need to better understand how this predator impacts the control of important crop pests, such as potato psyllids. We assessed the interactions between N. tenuis and B. cockerelli in three different environmental settings. First, we estimated the numeric response of N. tenuis preying on B. cockerelli under laboratory and greenhouse conditions. Second, we evaluated the predator–prey interaction under controlled field cage conditions. Then, we exposed N. tenuis under controlled field release conditions to the natural occurrence of B. cockerelli. Finally, we assessed the compatibility between the use of N. tenuis as a biological control agent in a field study and its impact on ZC disease incidence, severity in potato tubers, and potato yield. Laboratory and greenhouse experiments resulted in diverse types of functional model responses, including exponential and linear mathematical models. Our findings revealed a significant predation effect exerted by N. tenuis, resulting in a reduction of more than fourfold in the number of B. cockerelli nymphs per cage. Specifically, the nymphal population decreased from 21 ± 3.2 in the absence of N. tenuis to 5 ± 1.6 when N. tenuis was present. Furthermore, the combination of N. tenuis with a reduced insecticide program increased potato yields, but only reduced ZC tuber incidence in one of two potato cultivars evaluated, and in one season. Findings from these studies indicate that N. tenuis could be effective as a biological control agent for B. cockerelli in potato production in South Texas. This is the first report of N. tenuis preying on immature stages of any psyllid species.

There is evidence that all plants coexist with endophytes, indicating a fundamental role that is unknown. The objective was to evaluate the biotechnological potential of endophytes from Passiflora edulis f. edulis in two aspects: as a plant growth promoter and as a control for the pathogen Fusarium oxysporum. An in vitro phase was used in which the antifungal activity in a dual culture was studied, where the UNE075 and UNE004 fungi inhibited the radial growth of the pathogen by up to 67.63 % and 63.89 %, respectively. Additionally, higher inhibition percentages were seen with UNE075 (33.78 %) and UNE098 (32.32 %) because of the action of volatile organic compounds on F. oxysporum. Likewise, the production of indoleacetic acid (IAA) as a growth-promoting compound was quantified, with notable results with UNE017 (11.99 µg/mL) and UNE022 (7.59 µg/mL). The capacity of the fungi to solubilize phosphorus was determined. UNE098 generated the greatest solubilization by reducing the pH culture medium. In the in vivo phase in the greenhouse, the effect of inoculation with endophytes on the growth of P. edulis f. edulis plants was evaluated. Biomass accumulation and leaf area were determined, where UNE067 stood out because of its effect on fresh weight, total dry weight. In general, the evaluated endophytes have biotechnological potential for use in organic crop management programs and for biological control. [ABSTRACT FROM AUTHOR]

Jalapeño peppers (Capsicum annuum var. Jalapeño) represent one of the most important crops in Mexico. However, many plant diseases, such as wilt caused by strains of the genus Fusarium, reduce its yield. A sustainable alternative to control diseases is the use of biological control agents (BCAs), for example, beneficial microorganisms such as strains of the genus Bacillus. This study aims to analyze the potential use of B. cabrialesii subsp. tritici TSO2T as a BCA and elucidate its potential modes of action against Fusarium strains causing wilt in Jalapeño peppers. For this, symptomatic samples were collected in a commercial field in the Yaqui Valley, Mexico. Six Fusarium isolates were morphologically and molecularly characterized. After pathogenicity tests, F. languescens CE2 was found to be pathogenic. In screening assays for biocontrol bacteria, strain TSO2T, which was isolated from soil in a wheat commercial field under an organic production system and preserved in the Culture Collection of Native Soil and Endophytic Microorganisms (COLMENA), had the best biocontrol effect against CE2, and its cell-free filtrate reduced mycelial growth by 30.95%. Genome mining (antiSMASH) of strain TSO2T allows us to identify gene clusters associated with biocontrol, such as fengycin, surfactin, bacillibactin, bacilysin, bacillaene, subtilosin A, and sporulation killing factor, which codify to antimicrobial metabolites and are associated with swarming motility of the studied beneficial strain. These results demonstrate the effectiveness of B. cabrialesii subsp. tritici TSO2T as a potential BCA for the control of Fusarium wilt, through competition and a complex of antifungal metabolites, which still need to be validated through metabolomic analysis. This study highlights the importance of the use of integrative genomic and bioactivity-guided methodologies in understanding biocontrol pathosystems. [ABSTRACT FROM AUTHOR]

Development of new biological preparations to control Heterobasidion root rot is a complex process, but when a potential antagonist is identified, cultivation of the fungus is required. In this study, five different substrates (deciduous sawdust, coniferous sawdust, rye bran, straw and corn kernels) were tested as substrates for the cultivation of three fungal species: Bjerkandera adusta, Phlebiopsis gigantea, and Sistotrema brinkmannii, which could be potentially used against Heterobasidion spp. Mycelial growth was evaluated visually, and oidia production was estimated microscopically. In the straw substrate, P. gigantea produced significantly more (p < 0.05) oidia compared to the other substrates. In addition, oidia production at two different incubation temperatures were compared. As a result, the best substrate for cultivation of all three fungal species was coniferous sawdust. [ABSTRACT FROM AUTHOR]

Fruit flies (Diptera: Tephritidae) are serious pests that affect fruit production and marketing. Both third instar larvae and pupae are biological stages that persist in the soil until adult emergence. Entomopathogenic nematodes (ENs) are biological control agents that are used to control agricultural pests in greenhouse or field conditions. Several studies have been carried out under laboratory and field conditions showing how ENs can be applied within an area-wide integrated pest management approach to control fruit fly species in orchards and backyard fruit trees. In this review, we analyze how soil physical characteristics and biotic factors affect the performance of these biological control agents. Of the reviewed papers, more than half evaluated the influence of soil texture, humidity, temperature, and other factors on the performance of infective juveniles (IJs). Abiotic factors that significantly influence the performance of IJs are temperature, humidity, and texture. Among the biotic factors that affect IJs are fungi, bacteria, mites, insects, and earthworms. We conclude that ENs have the potential to be applied in the drip area of fruit trees that are infested by fruit flies and contribute to their suppression. This approach, in conjunction with an area-wide pest management approach, may contribute to pest suppression and increase the sustainability of agroecosystems. [ABSTRACT FROM AUTHOR]

Abstract Background As a biological control agent, entomopathogenic fungus (EPF) can give an alternative to high-risk pesticides. Metarhizium anisopliae is one of the most promising pest controls EPF in the worldwide. Result On fungi-specific selective media, the EPF isolate SVPUAT was isolated from Western Uttar Pradesh, India. The isolate was identified as M. anisopliae (GenBank accession no. OP962431) after molecular screening utilizing PCR amplification with the internal transcribed spacer (ITS) region primer. In a contact toxicity experiment, the isolate SVPUAT was tested against the 4th instar larvae of Helicoverpa armigera (Hubner) at concentrations ranging from 103 to 1010 spores ml−1. The lethal time LT50 and LT90 values for the 4th instar larvae of H. armigera injected with 1 × 1010 spores ml−1 were 3.46 and 5.54 days, respectively. Conclusions The present M. anisopliae isolate SVPUAT was identified using the ITS-5.8s rDNA region from GenBank and has showed significant pathogenicity to H. armigera. More research is needed to prove the efficacy against various pests of economic important as a legitimate choice for an integrated pest management program.

Cassia fistula L. is known as Golden shower or Amaltas has therapeutics importance in health care since ancient times. It shows a pivotal role in diseases prevention due to their valuable ingredients in different parts of plants. One of known hemipterous insect pest, attacking on this valuable tree is Oxyrachis tarandus Fab. (Hemiptera: Membracidae), its nymphs and adults feed gregariously on the sap of the shoot of host plant results in the stunting or death of the infested shoot. Oxyrachis tarandus population may be checked by some natural parasitoids. Mirufens Girault is one of important egg parasitoid recorded on this hemipterous insect pest, attacking on different host plants. In the present study, we are recorded egg parasitoid M. afrangiata from the eggs of Oxyrachis tarandus, infesting Cassia fistula plant for the first time. Re-described and illustrated two species of the genus Mirufens; M. afrangiata and M. brevifuniculata along with first male record of M. brevifuniculata. An updated key to the Indian species of Mirufens are also provided. [ABSTRACT FROM AUTHOR]

Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens apple and pear production. It is mainly controlled by using antibiotics, such as streptomycin. Due to development of E. amylovora resistant strains and the excessive agricultural use of antibiotics, there is an increased awareness of the possibility of antibiotic resistance gene transfer to other microbes. Urgent development of biocontrol agents (BCAs) is needed that can be incorporated into integrated pest management programs as antibiotic alternatives. A novel phage-carrier system (PCS) that combines an antagonistic bacterium, Pantoea agglomerans, with its ability to act as a phage-carrier bacterium for Erwinia phages has been developed. The low viability of P. agglomerans cells following spray-drying (SD) has been a challenge for the industrial-scale production of this PCS. Here, an SD protocol was developed for P. agglomerans by modifying the growth medium and bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to the industrial-scale production of the BCA/PCS. The P. agglomerans viability was greater than 90% after SD and had a shelf life at 4 °C of 4 months, and reconstituted cells showed a 3 log reduction in E. amylovora counts with a pear disc assay.

We model the spatiotemporal dynamics of a community consisting of competing weed and cultivated plant species and a population of specialized phytophagous insects used as the weed biocontrol agent. The model is formulated as a PDE system of taxis–diffusion–reaction type and computer-implemented for one-dimensional and two-dimensional cases of spatial habitat for the Neumann zero-flux boundary condition. In order to discretize the original continuous system, we applied the method of lines. The obtained system of ODEs is integrated using the Runge–Kutta method with a variable time step and control of the integration accuracy. The numerical simulations provide insights into the mechanism of formation of solitary population waves (SPWs) of the phytophage, revealing the factors that determine the efficacy of combined application of the phytophagous insect (classical biological method) and cultivated plant (phytocenotic method) to suppress weed foci. In particular, the presented results illustrate the stabilizing action of cultivated plants, which fix the SPW effect by occupying the free area behind the wave front so that the weed remains suppressed in the absence of a phytophage.

Schistosomiasis is a parasitic disease caused by Schistosoma worm infection. Some species of snails can serve as the intermediate hosts for the parasite. Numerous interventions have been performed to repress the snail population. One of them is the use of molluscicide. Nevertheless, it is debated that molluscicide intervention has negative impacts on the ecosystem. To investigate the impact of more environmentally friendly interventions, we develop a schistosomiasis model with treatment, habitat modification and biological control. The biological control agent examined in our model is a snail predator. Moreover, to investigate the impact of snail habitat modification, we assume that the snail population grows logistically. We show that all solutions of our model are non-negative and bounded. We also study the existence and stability conditions of equilibrium points. The basic reproduction numbers are determined using the next-generation operator. Linearization combined with the Routh-Hurwitz criterion is used to prove the local stability condition of disease-free equilibrium points. Bifurcation theory is applied to investigate the local stability condition of the endemic equilibrium points. To examine the global behavior of our model, we use asymptotically autonomous system theory and construct a Lyapunov function. We perform several numerical simulations to validate and support our deductive results. Our results show that early treatment can reduce the basic reproduction number and schistosomiasis cases. In addition, modifying snail habitat and releasing the snail predator at the snail habitat can reduce schistosomiasis prevalence. We suggest using snail predators which can hunt and kill snails effectively as a biological control agent.

This study determined the efficacy of the Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) alone or combined with the diatomaceous earth DEA (a mixture of DE + abamectin) against adults and larvae of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). DEA was evaluated at 50 ppm while the fungi at 1.6 × 105, 1.6 × 106, and 1.6 × 107 conidia/kg wheat). Mortalities were assessed after 7 or 14 days of exposure, while progeny reduction in adults after 30, 60, 90, or 120 days. The radial fungus growth was significantly affected by the dose of DEA. Mortalities were higher in the combined treatments compared to the application of DEA or B. bassiana alone for both larvae and adults. Larvae were more susceptible than adults in all treatments and exposure intervals. Insect survival and progeny production were recorded for four months. Significantly fewer progeny was noted on wheat treated with DEA + B. bassiana treatments compared with control. The maximum number of mycosed cadavers and the rate of sporulation were observed at the lowest dose of B. bassiana alone, followed by the higher doses gradually. These findings indicate that the DEA + B. bassiana combinations can efficiently control T. castaneum, providing long-term protection of wheat. [ABSTRACT FROM AUTHOR]

Background: As a biological control agent, entomopathogenic fungus (EPF) can give an alternative to high-risk pesticides. Metarhizium anisopliae is one of the most promising pest controls EPF in the worldwide. Result: On fungi-specific selective media, the EPF isolate SVPUAT was isolated from Western Uttar Pradesh, India. The isolate was identified as M. anisopliae (GenBank accession no. OP962431) after molecular screening utilizing PCR amplification with the internal transcribed spacer (ITS) region primer. In a contact toxicity experiment, the isolate SVPUAT was tested against the 4th instar larvae of Helicoverpa armigera (Hubner) at concentrations ranging from 103 to 1010 spores ml−1. The lethal time LT50 and LT90 values for the 4th instar larvae of H. armigera injected with 1 × 1010 spores ml−1 were 3.46 and 5.54 days, respectively. Conclusions: The present M. anisopliae isolate SVPUAT was identified using the ITS-5.8s rDNA region from GenBank and has showed significant pathogenicity to H. armigera. More research is needed to prove the efficacy against various pests of economic important as a legitimate choice for an integrated pest management program. [ABSTRACT FROM AUTHOR]

Phytophthora infestans is the pathogenic fungus causing potato late blight. The quality of chemical control agents is uneven and new biological control agents are urgently required. Therefore, in this study, Dingxi City, Gansu Province, where potato late blight incidence is high, was selected as the test place, and two new biocontrol agents and three conventional chemical agents were introduced to carry out a comparison test of indoor bacteriological inhibition and field control efficiency, to explore the effects of new biocontrol agents on potato late blight control efficiency and yield. Biocontrol agent, 10.5 billion CFU/g Polymyxa · Subtilis WP, had a bacteriostatic effect of 96.7% indoors and 76.5% in the field and increased the yield by 7.70% compared with the control treatment. The bacteriostatic effect of 68% Mefenoxam·Mancozeb WP in the laboratory conditions was 98.3%, in the field 73.1%, and the yield was 7.51% higher than that of the control treatment. There was no significant difference between the two treatments except for control effect in the field. The indexes of the two treatments were significantly better than that of the biocontrol agent 1 billion CFU/g Bacillus marinus WP, and chemical treatments of 32.5% Benzoyl ·Azoxystrobin SC and 50% Metalaxyl · Propineb WP. In conclusion, the new biocontrol agent of 10.5 billion CFU/g Polymyxa·Subtilis WP could be used as the control agent to control potato late blight in Dingxi City. [ABSTRACT FROM AUTHOR]