Biological Control Strategies Research Articles

Effective biological control of chickpea rabies (Ascochyta rabiei) through systemic phytochemical defenses activation by Trichoderma roots colonization: From strain characterization to seed coating

Chickpea (Cicer arietinum) is a legume of great economic and agricultural importance worldwide, whose crop is severely affected by rust or Ascochyta blight, caused by the fungus Ascochyta rabiei. The fungal genus Trichoderma includes several species widely characterized as effective biological control agents against crop pathogens. First, this work characterized several species of the genus Trichoderma as potential biological control agents of A. rabiei directly (in vitro confrontation) or indirectly in chickpea plants (activation of systemic resistance), selecting T. harzianum EN1 as the most efficient strain. Subsequently, different materials were tested as coatings to apply the T. harzianum conidia on chickpea seeds, determining that gum arabic at 1 % concentration was the one that most promoted the germination of conidia and seeds. The third phase of the study was based on the application of the coating and T. harzianum conidia on chickpea seeds and to study plant survival after infection with the pathogen A. rabiei, characterizing root colonization by Trichoderma and systemic hormonal and metabolic changes related to the induction of systemic defenses. The treatment of chickpea seeds with gum arabic and T. harzianum conidia was found to increase Trichoderma-root colonization and to improve plant survival. The induction of systemic ethylene- and melatonin-mediated resistance, which led to the accumulation of nicotinic acid in plant tissues, was considered the cause of such a protection. Therefore, T. harzianum applied as seed coating with gum arabic could be a good biological control strategy against A. rabiei on chickpea, due to the induction of systemic resistance.

DETERMINATION OF ENTOMOPATHOGENIC NEMATODE FAUNA IN ŞIRNAK, TURKIYE

This study focuses on the isolation, identification, and characterization of entomopathogenic nematodes (EPNs) in Şırnak Province, Turkey. Between July and September 2023, we collected 256 soil samples, from which 11 EPN isolates were successfully recovered,representing a 4.3% of the samples. These isolates were identified using morphological examinations and molecular diagnostics, including mitochondrial COI and 18S rDNA gene regions. Our findings revealed a diverse population of EPNs, predominantly Heterorhabditis bacteriophora with five isolates, alongside four Steinernema species (one Steinernema carpocapsae, one Steinernema affine, and two Steinernema sp.). Phylogenetic analysis, employing the mitochondrial cytochrome oxidase subunit I (COXI) and the 18S rDNA gene regions, indicated low genetic variability within H. bacteriophora and greater diversity among Steinernema species. The study contributes significant insights into the EPN biodiversity in Şırnak Province and underscores the potential of these nematodes in biological pest control, offering a sustainable alternative to chemical pesticides. The results highlight the importance of local EPN isolates in the development of effective biological control strategies and the conservation of agricultural biodiversity.

Determination of Antagonistic Activities of Endophytic Bacteria Isolated from Different Wheat Genotypes Against Fusarium culmorum

This study aimed to evaluate the physiological and biochemical properties and enzyme activities of endophytic bacteria obtained from different wheat genotypes, as well as their effectiveness against Fusarium culmorum, which causes root and crown rot in wheat. The results obtained from double culture tests of isolates against F. culmorum showed that the inhibition rate varied between 80.56% and 13.90%. The inhibition rate against F. culmorum was 80.59% for Bacillus subtilis (MM11), 69.41% for Stenotrophomonas maltophilia (EY5), and 61.10% for Enterobacter sp. (MY3) under in vitro conditions, the most effective isolates. Pseudomonas putida (EM9) and Pseudomonas orientalis (MM21) isolates gave positive results in all tests in the production of amylase, cellulase, phosphatase, ACC deaminase, and siderophore. To identify six promising isolates, 16S rRNA gene-based sequence analysis was utilized. The efficacy of bacterial strains against F. culmorum, pot experiments were conducted in a growth room (in vivo). The results demonstrated that the combination of S. maltophilia, Enterobacter sp., and B. subtilis (MY3+EY5+MM11) yielded the most favorable outcomes in terms of disease severity, plant height, wet weight, dry weight, root wet weight, and root dry weight. The combination of Stenotrophomonas rhizophila, P. putida, and P. orientalis (EY1+EM9+MM21) exhibited promising results. Utilizing effective bacterial strains is anticipated to reduce the dependence on and costs associated with chemical fertilizers and pesticides while minimizing their environmental impact. Furthermore, these strains show potential for commercial applications pending further validation procedures. The findings from this study significantly contribute to the field of biological control strategies against F. culmorum by leveraging the diverse capabilities of endophytic bacteria.

Influence of Alternative Prey on the Functional Response of a Predator in Two Contexts: With and without Intraguild Predation.

In biological control, joint releases of predators and parasitoids are standard. However, intraguild predation (IGP) can occur when a predator attacks a parasitoid, potentially affecting pest control dynamics. In addition to the focal prey (FP), Trialeurodes vaporariorum, the intraguild predator (IG-predator) Geocoris punctipes can consume the parasitoid Eretmocerus eremicus (IG-prey). In this IGP context with multiple prey, an alternative prey (AP), like the aphid Myzus persicae, may influence interactions. Theory predicts that, in simple interactions, a predator's functional response (FR) to the FP changes with the presence of an AP. However, whether this holds in an IGP context is unknown. In this study, we empirically tested that prediction. Our results show that without IGP, G. punctipes exhibits a generalized FR with and without AP. Nevertheless, with IGP, the predator exhibited a Type II FR at low and high AP densities, increasing pressure on the FP and potentially favoring short-term biological control strategies. However, when 25 AP were offered, the predator's response shifted, underscoring the importance of monitoring AP densities to prevent potential disruptions in FP control. In both contexts, the increase in AP produced a handling time increase and a decrease in consumption rate. These results indicate that the theoretical prediction of the effect of AP on the FR is met only under specific conditions, and the complexity of multitrophic interactions must be considered.

Compatibility of Native Strains of Beauveria peruviensis and Metarhizium sp. as Strategy for Biological Control of Coffee Berry Borer (Hypothenemus hampei, Ferrari)

Coffee is a crop of global importance, and it is especially important in countries such as Peru. However, the presence of the pest Hypothenemus hampei represents a significant challenge with a notable economic impact. This study addresses this challenge using entomopathogenic fungi such as Beauveria peruviensis and Metarhizium sp. The compatibility of three strains of Beauveria peruviensis (F5, P19, and P4) and seven strains of Metarhizium sp. (MMR-M1, LLM-M2, MHR-M4, PMR-M12, MMR-M15, TOR-M16, and GOR-M18) was evaluated for approximately 2 months. A total of 14 treatments were designed, each consisting of one strain of B. peruviensis and one strain of Metarhizium sp. The Skott–Knott test (p ≤ 0.05) revealed that strain LLM-M2 (Metarhizium sp. strain) had the highest conidial production (3.75 × 107 conidia/mL). Except for T6 (MMR-M1/F5), which showed a mutual growth type interaction (type A), all other strain combinations showed a type B interaction (mutual inhibition by contact or separation between colony margins (<2 mm)). The combination with the highest germination rate was T10 (MHR-M4/F5) at 89%. In addition, the pathogenicity of the combined strains was evaluated, showing a direct correlation with mortality and mycosis development in the coffee berry borer in treatments T1 (PMR-M12/P19), T10 (MHR-M4/F5), and T11 (MMR-M15/P19), reaching 100% mortality at 72 h with grade 4 mycosis. Regarding mycelial growth, treatments T1 (PMR-M12/P19), T4 (MMR-M1/P19), and T12 (GOR-M18/P19) reached the highest percentages, between 85.8% and 83.10% at 240 h. This study demonstrates the feasibility of using native strains of B. peruviensis and Metarhizium sp. as a biocontrol strategy against the coffee berry borer in the Amazon department, presenting them as an alternative to traditional chemical methods.

Biological Approaches for Sustainable Pest and Disease Management in Pulse Crops

Pulse crops, including lentils, peas, chickpeas, and beans, play a crucial role in addressing global food security and nutritional needs. However, their production is often hampered by various pests and diseases, leading to significant yield losses. Conventional pest and disease management practices, heavily reliant on synthetic chemical pesticides, have raised concerns about environmental sustainability, human health, and the development of resistance in target organisms. In recent years, biological approaches have emerged as promising alternatives for sustainable pest and disease management in pulse crops. This review provides a comprehensive overview of various biological control strategies, including the use of beneficial microorganisms, plant extracts, and other eco-friendly methods. The review discusses the mode of action, efficacy, and potential applications of these approaches in combating major pests and diseases affecting pulse crops. Additionally, it highlights the challenges and future prospects of integrating biological control methods into integrated pest and disease management programs. By adopting these sustainable practices, pulse crop production can be enhanced while minimizing the environmental footprint and promoting long-term ecological balance. The review serves as a valuable resource for researchers, extension specialists, and stakeholders in the agricultural sector, emphasizing the importance of biological approaches in achieving sustainable and resilient pulse crop production systems.

Enhancing biological control of postharvest green mold in lemons: Synergistic efficacy of native yeasts with diverse mechanisms of action.

Argentina is among the most important lemon fruit producers in the world. Penicillium digitatum is the primary lemon fungal phytopathogen, causing green mold during the postharvest. Several alternatives to the use of synthetic fungicides have been developed, being the use of biocontrol yeasts one of the most promising. Although many of the reports are based on the use of a single yeast species, it has been shown that the combination of agents with different mechanisms of action can increase control efficiency through synergistic effects. The combined use of native yeasts with different mechanisms of action had not been studied as a biological control strategy in lemons. In this work, the mechanisms of action of native yeasts (Clavispora lusitaniae AgL21, Clavispora lusitaniae AgL2 and Clavispora lusitaniae AcL2) with biocontrol activity against P. digitatum were evaluated. Isolate AgL21 was selected for its ability to form biofilm, colonize lemon wounds, and inhibit fungal spore germination. The compatibility of C. lusitaniae AgL21 with two killer yeasts of the species Kazachstania exigua (AcL4 and AcL8) was evaluated. In vivo assays were then carried out with the yeasts applied individually or mixed in equal cell concentrations. AgL21 alone was able to control green mold with 87.5% efficiency, while individual killer yeasts were significantly less efficient (43.3% and 38.3%, respectively). Inhibitory effects were increased when C. lusitaniae AgL21 and K. exigua strains were jointly applied. The most efficient treatment was the combination of AgL21 and AcL4, reaching 100% efficiency in wound protection. The combination of AgL21 with AcL8 was as well promising, with an efficiency of 97.5%. The combined application of native yeasts showed a synergistic effect considering that the multiple mechanisms of action involved could hinder the development of green mold in lemon more efficiently than using single yeasts. Therefore, this work demonstrates that the integration of native yeasts with diverse modes of action can provide new insights to formulate effective microbial consortia. This could lead to the development of tailor-made biofungicides, allowing control of postharvest fungal diseases in lemons while remaining competitive with traditionally used synthetic chemicals.

Bacillus amyloliquefaciens: a versatile antimicrobial Firmicute for the suppression of wilt caused by Ralstonia pseudosolanacearum in tomato

ABSTRACT Rhizosphere bacteria based biological control strategy is an eco-friendly approach to protect crops from various plant diseases. Among these, spore-forming Bacillus, abundant in the rhizosphere, provide unique advantages for plant health. This study focused on characterising two tomato rhizosphere-associated Bacillus amyloliquefaciens strains (Trb7 and Trb11), highly effective against the bacterial wilt pathogen Ralstonia pseudosolanacearum in vitro. Species identification was based on partial 16S rRNA gene sequencing, supported by phylogenetic analysis. Five antimicrobial peptide (AMP) genes (surfactin, fengycin, bacilysin, subtilin, and spore protein) were detected in both the isolates of B. amyloliquefqciens using specific molecular markers. Greenhouse trials showed that prophylactic application of these isolates led to an 83.4% reduction in tomato bacterial wilt, with only 16.6% wilt incidence compared to the 100% in the R. pseudosolanacearum-inoculated control. Moreover, these B. amyloliquefaciens isolates exhibited plant-growth-promoting traits in vitro. Interestingly, they also showed significant inhibition of mycelial growth against Sclerotium rolfsii and Alternaria alternata, major fungal pathogens in tomatoes. Overall, our findings highlight the potent bactericidal role of B. amyloliquefaciens isolates in suppressing R. pseudosolanacearum in tomatoes. Key highlights Two among the 100 Bacillus displayed antibacterial activity against Ralstonia pseudosolanacearum. Antibacterial firmicutes was identified as Bacillus amyloliquefaciens through the 16S rRNA gene sequence analysis. Five AMP genes (srfAA, fenD, bacA, spas, and spoVG) were identified in the isolates. Delivery of B. amyloliquefaciens drenching on rhizosphere significantly reduced wilt. Additionally, B. amyloliquefaciens showed the antifungal activity on Sclerotium rolfsii and Alternaria alternata.

Artificial Adult Diet as a New Tool for Improving a Biocontrol Program with Predatory Hoverflies

Syrphine hoverflies (Diptera: Syrphinae) are important predators of aphids in agricultural crops. While the use of flowering plants to enhance their efficacy is well established, recent research has developed an artificial diet for adult hoverflies consisting of a sugar solution and pollen in a dispenser. To ensure that the artificial diet is suitable to support hoverfly reproduction, a comparative analysis was conducted between a natural diet of flowering buckwheat plants versus an artificial diet consisting of artificial flowers (including honey solution and pollen), complemented by a sugar solution disperser. The study evaluated the fecundity, fertility, oviposition period, egg hatchability, and overall lifespan of the American hoverfly, Eupeodes americanus (Wiedemann 1830). The results indicate that the artificial diet does not negatively impact the reproductive parameters of E. americanus when compared to the buckwheat-based diet. Consequently, artificial diets emerge as a promising and more convenient alternative to flowering plants to support hoverflies in biological control strategies and for their mass rearing in research facilities and commercial insectaries.

Diversity of Parasitoid Wasps and Comparison of Sampling Strategies in Rice Fields Using Metabarcoding.

A comprehensive and precise evaluation of Arthropoda diversity in agricultural landscapes can enhance biological pest control strategies. We used Malaise traps and sweep nets to collect insects from three double-cropping paddy fields. DNA was extracted from the ethanol preservative of the Malaise traps and from tissue samples of selected parasitoid wasps. This was followed by amplification using DNA barcoding primers to prepare high-throughput sequencing libraries. We annotated a total of 4956 operational taxonomic units (OTUs), encompassing 174 genera and 32 families of parasitoid wasps. The ethanol filter method efficiently captured a wide range of information. However, the method has low resolution and may result in a reduced estimate of species abundance. Additional insect species were also identified in the parasitoid samples. This suggests that high throughput sequencing from adult parasitoid wasps can also detect host species, enabling a better understanding of host species and providing insights into food webs.

Optimizing the Release Pattern of Telenomus podisi for Effective Biological Control of Euschistus heros in Soybean.

An augmentative biological control program using the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Platygastridae) is a promising tool for the management of the brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) in soybeans. The T. podisi are released as adults or pupae within lab-reared E. heros eggs. Because of the small size of the parasitoid and potentially limited dispersal ability, determining the optimal release pattern is critical for biological control of the target pest. This study used sentinel E. heros eggs to investigate T. podisi dispersal within soybean crops during two distinct phenological stages: the beginning of flowering (Vn-R1) and the grain-filling phase (R5-R6). Data were analyzed using semi-variograms and kriging maps. The results indicate significant differences in parasitism rates between the two plant growth stages and among different matrices. The maximum dispersal range for T. podisi was calculated at 39.0 m in the Vn-R1 stage with a maximum parasitism rate of 42%, while in the R5-R6 stage, the maximum dispersal range was calculated to be 30.9 m with a maximum parasitism of 73%. Therefore, it is recommended that release points for T. podisi be spaced no further than 30 m apart. These results provide valuable insights for future research and applications in biological control strategies, including adjustment of the logistics and release technique depending upon the crop phenological stage.

Relevance of diet diversification in the coexistence between Orius laevigatus and Amblyseius swirskii: prey switching and intraguild predation

AbstractOmnivores obtain resources from more than one trophic level, choosing food based on quantity and quality. They usually engage in intraguild predation (IGP) when prey is scarce. Orius laevigatus is an example of omnivore that becomes superior predator of the predatory mite Amblyseius swirskii when released in a combined system under low levels of the preferred prey, the thrips Frankliniella occidentalis. Here, we test two genetically enhanced O. laevigatus strains for bigger size and better fitness feeding on pollen (BIG30 and 2POL-11, respectively), hence with a wider dietary diversification, to elucidate the potential effects on prey preference and IGP on the predatory mite, in comparison with a commercial population of O. laevigatus. To do that, predation rates were registered on adult phytoseiids solely or in a choice situation at different availability ratios of adult thrips under laboratory conditions. The effect of pollen as supplemental food on IGP and prey preference was examined, too. We found that our two enhanced lines killed up to 9% less predatory mites and fed preferably on adult thrips, compared to the commercial population. While BIG30 showed a significantly higher total predation rate, killing up to 150% more adult thrips, 2POL-11 is defined as an efficient user of resources, switching between different prey and pollen showing low IGP. Pollen supplementation had a significant effect on reducing IGP, but only for 2POL-11 the influence on prey preference was significant. The theory of intraguild predation and the impact of prey switching on food webs and biological control strategies are also discussed.

Contamination and Control of Mycotoxins in Grain and Oil Crops.

Mycotoxins are carcinogenic, teratogenic and mutagenic toxic compounds produced by some filamentous fungi, which are extremely harmful to corn, rice, wheat, peanut, soybean, rapeseed and other grain and oil crops, and seriously threaten environmental safety, food safety and human health. With the rapid increase in the global population and the expansion of the main crop planting area, mycotoxin contamination has increased year by year in agricultural products. The current review aimed to summarize the contamination status and harmful effects of major mycotoxins of grain and oil crops and the environmental factors that impact mycotoxin contamination. Further, control measures of mycotoxin contamination, especially the biological control strategies, were discussed.

Volatile organic compounds (VOCs) produced by indigenous Bacterium strain BS1727 as antifungal agents against Ganoderma boninense

Ganoderma boninense, the causative agent behind basal stem rot (BSR) disease in oil palm, instigated a pressing need for innovative and ecologically sustainable strategies to counter its impact. Biological control strategies, particularly employing bio-fungicides, have emerged as environmentally friendly alternatives for managing oil palm plant diseases. This study delved into harnessing the biocontrol potential of Indigenous bacterial isolate by investigating and evaluating its bioactive compounds of ethyl acetate extract with the capacity to suppress G. boninense growth in oil palm plants. Molecular identification was utilized to identify of bacterial isolate using 16S rRNA primers (5′- AGA GTT TGA TCC TGG CTC AG– 3′) and (5′- GGA TAC CTT GTT ACG ACT T– 3′). The agar well diffusion technique and scanning electron microscopy (SEM) were utilized to assess the inhibitory effects of bacterial ethyl acetate extract against G. boninense. A comprehensive analysis of the bacterial ethyl acetate extracts was conducted by gas chromatography - mass spectrometry (GC–MS). Molecular identification confirmed that the bacterial isolate was Bacterium strain BS1727. By employing SEM, the ethyl acetate extracts had influenced on G. boninense mycelial architecture. The exposure to the bacterial ethyl acetate extracts induced degradation and morphological distortion of the mycelial structure, serving as an indicator of its impact on the mycelium's structural modulation. Noteworthy, the spectrum of bioactive compounds was a subset of aromatic hydrocarbons, encompassing volatile organic compounds (VOCs). Based on GC–MS analysis, among the VOCs, acetic acid butyl ester and toluene showed the highest relative peak areas, 46.34 % for acetic acid butyl ester and 31.82 % for toluene, respectively. Ethylbenzene had a relative peak area of 5.4 %, 1,1,2-trichloroethane 4.41 %, and allyldimethyl (prop-1-ynyl) silane 3.17 %. The remaining compounds were 6-undecyl-5,6-dihydro-2H-pyran-2-one, 3-decen-5-one, 2-methyl-, and o-cymene, with the relative peak areas were below 1 %. These findings explained the inherent capacity of antifungal compounds as a viable strategy in inhibiting the growth of G. boninense.

Temperature-induced effects on development, reproduction, and predation of Harmonia axyridis fed on first instar larvae Spodoptera litura.

Since metabolism, survival, and reproduction in hexapods are closely related to temperatures; changes in the mean and variance of temperature are major aspects of global climate change. In the typical context of biological control, understanding how predator-prey systems are impacted under thermal conditions can make pest control more effective and resilient. With this view, this study investigated temperature-mediated development and predation parameters of the predator Harmonia axyridis against the potential prey Spodoptera litura. The age-stage, two-sex life table of the predator was constructed at four temperatures (i.e. 15, 20, 25, and 30°C) by feeding on the first instar larvae of S. litura. Our results showed that the mean generation time (T) decreased but the intrinsic rate of increase (r) and the finite rate of increase (λ) increased with increased temperature. The mean duration of the total preadult stage decreased with higher temperatures. The T and r were 70.47 d and 0.0769 d-1 at 15°C; 58.41 d and 0.0958 d-1 at 20°C; 38.71 d and 0.1526 d-1 at 25°C; and 29.59 d and 0.1822 d-1 at 30°C, respectively. The highest net reproductive rate (R0) and fecundity were obtained at 25°C. The highest λ (1.1998 d-1) and lowest T (29.59 d) were obtained at 30°C, whereas the maximum net predation rate (C0) was at 25°C. Total population and predation rates projections were the highest at 30°C. Based on these findings, we anticipate that biological control strategies for this predator release against S. litura should be attuned to warming scenarios to achieve better biocontrol functions.

Increasing the tolerance of Trichoderma harzianum T-22 to DMI fungicides enables the combined utilization of biological and chemical control strategies against plant diseases

Demethylase inhibitors (DMIs) targeting CYP51 proteins in fungi are often used for plant disease management. Trichoderma harzianum, a widely used biocontrol agent, however, is sensitive to DMIs. This negates their combined use as a strategy in practices. Increasing the tolerance of T. harzianum to DMIs represents a feasible solution to this problem. In this regard, the overexpression of a CYP51B variant in Mycosphaerella graminicola (MgCYP51B-v) conveys increased tolerance to DMIs. Molecular docking indicated a distinct decrease in the affinity of MgCYP51B-v with DMIs. Since CYP51B proteins are conserved in M. graminicola and T. harzianum, we attempted to increase DMI tolerance in T. harzianum by heterologously expressing MgCYP51B-v. A series of T. harzianum mutants were obtained that were able to develop colonies on tebuconazole-amended medium. Two representative mutants were selected for further studies that confirmed that they were resistant to tebuconazole with resistance factors (RFs) of approximately 10.0. The mutants maintained a similar level of resistance after ten rounds of subculture without fungicide, indicating that the fungicide resistance was stably inherited. The mutants also exhibited increased tolerance to other DMIs, including metconazole, ipconazole, hexaconazole, and prochloraz. Further assessment indicated that the DMI resistance in the mutants did not have any impact on their fitness. The improved compatibility between T. harzianum and DMIs enables the utilization of a combined strategy in which these disease control agents are used together. Such a strategy has the potential to provide synergistic disease control and prevent or delay the development of fungicide resistance.

Isolation and Characterization of fungal pathogens associated with Carica papaya L. and their biocontrol with Trichoderma sp.

Objective: In this work, we undertook the task of isolating and identifying Fusarium obtained from papaya fruits grown in the Veracruz region and carried out antibiotic tests to find a beneficial fungus that could exert biological control. Methodology: Juvenile fruits with necrosis and rot were collected from papaya plants of the Maradol variety, from here the pathogenic fungi were obtained, which were morphologically and molecularly characterized using the ITS gene. Subsequently, the isolated pathogenic fungi were confronted with the Trichoderma sp fungus. Results: Ten isolates were obtained, of which four were Fusarium solani. From the confrontations, a 66% to 100% percentage of inhibition in these pathogenic fungi was obtained. Limitations of the study: It is proposed that future evaluations carry out long-term follow-ups to evaluate the persistence and effectiveness of biological control. Findings/conclusions: Timely identification of pathogens could represent a biological control strategy in disease management programs.

Biological Control and Cross Infections of the Neofusicoccum spp. Causing Mango Postharvest Rots in Spain

Mango is one of the main subtropical crops growing in southern Spain. Spanish mango fruit production can be efficiently transported to the rest of Europe, and these mangoes are very appreciated for their quality and flavour. However, postharvest rots have been detected in stored mango fruits, making their commercialization difficult. The causal agents associated with such rot symptoms have been isolated and identified. Because the mango crops used to share the same growing area with avocado crops, fungal presence on surrounding asymptomatic avocado fruits was also analysed to detect potential cross infections. Artificial inoculation with Neofusicoccum parvum and N. mediterraneum was able to reproduce rot symptoms in mango but was also able to induce rots in avocado fruits. To approach a biological control strategy against these rot-producing fungi, two very well-known antagonistic biocontrol bacteria, Pseudomonas chlororaphis PCL1606, and Bacillus velezensis UMAF6639, were tested. The obtained results revealed that both bacteria can control the fungal rots on stored mango and avocado fruits under controlled conditions. Additionally, the strain B. velezensis UMAF6639 showed the ability to persist on the fruit surface of adult commercial trees in experiments under open field conditions, helping to prevent the appearance of these postharvest diseases.

Cross-infectivity of Vorticella sp. across genera of mosquitoes for development of biological mosquito control strategies

Protists in general comprise about one-third of the parasitic species infecting arthropod vectors, the role of free-living and epibiotic ciliates on mosquitoes have been insufficiently studied either due to their low pathogenicity or facultative parasites. Studies have shown that exposure of Paramecium ciliate protists, like Vorticella species, to first instar Culex nigripalpus Theobald, larvae delayed larval development and reduced biomass of emerged adults due to competition for food sources like bacteria and other microbes essential to mosquito growth and survival. Thus, we report on the capacity of a Vorticella sp. protist’s ability to cross-infect host species and parasitize multiple mosquito larvae. The unique adapted behavior with the ability to remain on the exuviae in tree hole habitats provide a novel delivery system to develop products for target species-specific mosquitocides, larvicides, or viricides to be applied and sustained in aquatic systems.

Developmental status of duku stem-canker in Jambi

Dead molt disease or duku stem-canker disease has been widely discussed in several studies. Some suspect it is caused by Phytophthora palmivora, or Ceratocystis fimbriata, and possibly Botryodiplodia spp. In the last decade, studies and discussions in control efforts have been carried out. Control studies using biological control strategies continue to be carried out, especially in the South Sumatera region, as well as control studies using pesticides have also received a lot of attention, but the control results have not reached a satisfactory stage. There are still many duku plants that have experienced widespread mortality. Finally, we will discuss about the research that has done into developing effective and sustainable control strategies.