This research about the implementation of bacteria in papaya plantation soil in Kebumen that has been isolated and characterized and purified. This study aims to determine the potential of local ...isolate bacteria from papaya agricultural soil: 1). as PGPR bacteria or fertilizing bacteria for chili, eggplant and tomato plants and 2) as a natural bioinsecticide. mealybugs on papaya plants. The samples used were bacteria from the preliminary isolation that had been carried out, namely from the genera Bacillus, Pseudomonas, Erwinia, Exyguobacterium, Serratia, Stenotropomonas, and Acinetobacter. The study was conducted using 50 stems of each plant. Bioinsecticides are applied to papaya trees that are attacked by mealybugs. Measurement of plant growth was measured at 7 days and 30 days after planting. As for bioinsecticides, spraying was carried out 3 times. The results of the study can be concluded in the form of the implementation of bacteria as PGPR which can increase the growth of cayenne pepper (Capsicum frutescens), purple eggplant (Solanum melongena L) and tomato (Solanum lycopersicum Mill) and can be used as a bioinsecticide to reduce mealybugs (Paracoccus marginatus) on papaya plants (Carica papaya L.)
*Wide use of botanical insecticides is limited by the availability of certain plants. *Studies are needed to improve RNAi efficiency and to assess their safety risk. *Microbial insecticides are ...promising, but they only control a narrow range of pests. *Multitarget approach should be a promising strategy in future pest control. *Nanoformulation could enhance stability and control the release of bioinsecticides.
Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.
Bacillus thuringiensis subsp. israelensis (Bti) spherical parasporal crystal contains several insecticidal proteins used as environmentally safe alternative to toxic chemical pesticides. The ...exploration of a Bti strain isolated from Qatar QBT220 genes encoding the δ-endotoxins responsible of the insecticidal activities revealed the alteration of a 14-kb DNA region including the δ-endotoxins cry10A and cyt1C genes of pBtoxis plasmid. The presence of all the insecticidal genes except cry10A and cyt1C was explained by a structural instability of the plasmid pBtoxis. However, when compared with the Bti reference strains H14 and QBT217 that carry all δ-endotoxins coding genes, it was found that QBT220, has a significantly higher insecticidal activity against the dipteran insect Aedes aegypti larvae despite of the plasmid pBtoxis structural instability due to the alteration of cry10A and cyt1C genes. In addition, QBT220 showed the highest δ-endotoxin synthesis per spore, compared with that of the wildtype strains. These findings confirm that the altered genes cry10A and cyt1C are not mandatory for Bti insecticidal activities and on the other hand show a possible inhibitory effect played by the 2 proteins Cry10A and Cyt1C on the insecticidal activities of the other insecticidal proteins. In addition, the QBT220 increased δ-endotoxins synthesis per cell, makes this strain a good candidate for possible applications in the industrial production of bioinsecticides.
•pBtoxis plasmid structural instability was illustrated by the alteration of 14-kb including the genes cry10 and cyt1C.•QBT220, has a significantly higher insecticidal activity against the dipteran insect Aedes aegypti larvae.•cry10A and cyt1C are not mandatory in Bti toxicity.•QBT220 showed the highest δ-endotoxin synthesis per spore, compared with that of the wildtype strains.•QBT220 is a good candidate for possible applications in the industrial production of bioinsecticides.
Fungal entomopathogens are suggested to be used as a bioinsecticide due to their biological persistence and ecological friendliness. Beauveria bassiana is an entomopathogenic fungus that can ...effectively control insect pests, including cocoa pod borer. This study aims to determine the level of effectivity of the B. bassiana (Bb) formulation product from Palu against cocoa pod borer pupae in vitro . This research used a completely randomized design (CRD) consisting of two factors: conidia concentrations and chitin treatments, which were repeated thrice. The conidia concentrations consisted of two levels, that were 106 and 107 conidia/mL. The chitin treatment included seven treatments: isolate from Kediri without formulation with chitin (Bb-K), isolate from Palu without formulation with chitin (Bb-P0), four formulations of isolates from Palu with the addition of chitin to various growth media (Bb-P1, Bb-P2, Bb-P3, and Bb-P4), and control (without Bb suspension). Bb-P0 and Bb-P2 treatments at a concentration of 107conidia/mL began to colonize CPB on the third day after the treatment application, while the other formulations started on the fifth day. However, Bb-P0 showed the lowest infection rate at the end of the observation. Contrarily, the data on the pupa-infected ratio showed that the Bb-P2 treatment was the highest compared to other treatments. It conformed to the adult emergence ratio that Bb-P2 exhibited the lowest, which means Bb-P2 has the most virulence of other formula. The result showed that PDA and PDB media-supplemented chitin was the most effective for culturing B. bassiana origin Palu before mass production.
Brinjal (Solanum melongena L.) is a popular vegetable in Bangladesh being nutritious, tasty, and cultivable throughout the year. Insect pests are the major constraint to its successful cultivation ...and production. The present study was conducted during the winter season when the sucking insect pests especially cotton aphids (Aphis gossypii Glover) are most abundant. Aphid infestation was observed in the brinjal plants since the early vegetative stage and sometimes the infestation rate reached up to 100 percent. Moreover, the infestation rate fluctuated with plants or duration. Aphids suck the cell saps resulting in stunting the growth of plants and yield reduction. As brinjal is consumed without peeling, contamination with toxic insecticides is a health concern. To address this, some bioinsecticides including abamectin preparation ‘Biomax M’, sodium lauryl ether sulphate preparation ‘Fizimite’, azadirachtin preparation ‘Fytomax’, Saccharopolyspora spinosa and Bacillus thuringiensis var. Kurstaki broth mixture preparation ‘Spinomax’, and potassium salt of fatty acid preparation ‘Fytoclean’ were selected to combat aphids. Besides, Voliam Flexi was applied as chemical control. A field study showed that abamectin preparation Biomax M was very potent against aphids showing zero percent aphid infestation. In addition, the chemical control Voliam Flexi 300 SC also provided zero percent aphid infestation. Therefore, Biomax M might be the non-toxic alternative to Voliam Flexi 300 SC for controlling aphids.
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•Aphis gossypii G. initiate infestation on the lower surface of the brinjal leaf at the early vegetative stage.•Abamectin preparation Biotin M controls the Aphis gossypii more successfully than other bioinsecticides.•Biotin M controls the aphid infestation like the Chemical insecticide Voliam flexi 300 SC.•Biotin M might be the alternative to the chemical insecticide Voliam Flexi 300 SC.
•New essential oil-based insecticide formulations were developed.•Seven EOs and four surfactants were used to develop nano emulsions.•Surfactant and sonication had a strong impact on the ...nano-emulsion characteristics.•Tween 80 sonicated EO-based nano-emulsions were the most stable over time.•Sonicated Artemisia EO + Tween 80 had the smallest droplets and the best stability.
Essential oils (EOs) are promising active ingredients for biopesticides, although their use under field conditions is limited by several criticisms concerning their high volatility and degradability. To overcome these negative qualities, EOs can be encapsulated inside nanostructures (i.e. nanoparticles and nano-emulsions), which can guarantee the preservation of the insecticidal properties. In the current study, oil in water (O/W) nano-emulsions of seven commercial EOs (15 % w/w of anise, artemisia, fennel, lavender, peppermint, rosemary, sage) were developed using different non-ionic surfactants and formulation processes, to identify the best possible surfactant/process to produce stable nano-formulations. The EOs were firstly examined by gas-chromatography analyses to identify their chemical constituents. Sage, rosemary, peppermint, lavender and artemisia EOs were characterized by high percentage (up to 50 % of the detected compounds) of oxygenated monoterpenes, while fennel and anise EOs were mainly constituted by phenylpropenes (e.g. anethol). Then, nano-emulsions were developed via the self-emulsifying process alone or in combination with sonication, using four surfactants with different Hydrophilic Lipophilic Balance (HLB) index (5 % w/w of Tween 20, Tween 80, Span 20 or Span 80). The physical characteristics (droplet size and surface charge) of nano-emulsions were analyzed using the dynamic light-scattering technique. Sonicated nano-formulations presented smaller and more homogeneous size of the micelles than the non-sonicated ones, resulting in more stable nano-emulsions. Furthermore, usually emulsions produced using Tween 80 as surfactant gave the best results in terms of droplet size and polydispersity index (PDI) values. Therefore, Tween 80 sonicated nano-emulsions were examined during a storage period of 28 weeks to determine their stability over time and possible alteration of their physical characteristics. Results suggest that these nano-formulations had a good stability over time, since relatively small increases in PDI and size values were recorded. Formulation stability is a key issue to consider when proposing botanical biopesticides for agricultural applications. Our study reports the first step in the introduction of EO-based nano-emulsions into practical application.
Bacillus thuringiensis subsp. israelensis (Bti) has been used in mosquito control programs to reduce nuisance in Europe for decades and is generally considered an environmentally-safe, effective and ...target-specific biocide. However, the use of Bti is not uncontroversial. Target mosquitoes and affected midges represent an important food source for many aquatic and terrestrial predators and reduction of their populations is likely to result in food-web effects at higher trophic levels. In the context of global biodiversity loss, this appears particularly critical since treated wetlands are often representing conservation areas. In this review, we address the current large-scale use of Bti for mosquito nuisance control in Europe, provide a description of its regulation followed by an overview of the available evidence on the parameters that are essential to evaluate Bti use in mosquito control.
Bti accumulation and toxin persistence could result in a chronic expose of mosquito populations ultimately affecting their susceptibility, although observed increase in resistance to Bti in mosquito populations is low due to the four toxins involved. A careful independent monitoring of mosquito susceptibility, using sensitive bioassays, is mandatory to detect resistance development timely. Direct Bti effects were documented for non-target chironomids and other invertebrate groups and are discussed for amphibians. Field studies revealed contrasting results on possible impacts on chironomid abundances. Indirect, food-web effects were rarely studied in the environment. Depending on study design and duration, Bti effects on higher trophic levels were demonstrated or not. Further long-term field studies are needed, especially with observations of bird declines in Bti-treated wetland areas. Socio-economic relevance of mosquito control requires considering nuisance, vector-borne diseases and environmental effects jointly. Existing studies indicate that a majority of the population is concerned regarding potential environmental effects of Bti mosquito control and that they are willing to pay for alternative, more environment-friendly techniques.
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•Bacillus thuringiensis subsp. israelensis (Bti) is widely used for mosquito control.•Risk of resistance to Bti is limited despite spores and toxins persistence.•Reported effects on non-target organisms challenge environmental safety of Bti.•Monitoring should be performed by independent bodies devoid of conflicts of interest.•Alternative mosquito control methods should be considered in conservation areas.
Maize is one of the important staple crops. The process of cultivating corn cannot be separated from pests and plant diseases, one of the attacking pests is Spodoptera frugiperda , which can attack ...the growing points of plants causing a decrease in corn production. Based on previous research conducted in vitro, bioinsecticide of Bacillus thuringiensis -base (Bt-base) liquid formula (namely Bashield ® ) was able to reduce pupal weight, the proportion of larvae-pupae, and pupal becomes abnormal. Action that can be taken to control this attack is by utilizing biological agent, B. thuringiensis strain BT2, as an alternative control. This research aims to evaluate or to determine the effectiveness of a new bioinsecticide of Bt-base liquid formula (Bashield ® ), as a control agent for S. frugiperda on maize in the field. This research was prepared at the Laboratory of Plant Protection and Environment, Universitas Trunojoyo Madura, and was conducted at the Horticultural Seed Garden, Socah District, Bangkalan Regency, East Java, Indonesia (7°05'17.2"S 112°42'32.0"E). The design used was a complete randomized block design (CRBD) with 4 treatments and 6 replications. The data were analyzed using 5% ANOVA and if there was a significant effect, then a DMRT follow-up test was carried out with a 5% level. The results showed that the 15% treatment was able to kill test larvae up to 78% with a high virulence level, and reduced damage up to 100%. In conclusion, the new Bt-base liquid formula, Bashield ® , has good potential for effective biocontrol and contributed as a new biopesticide for S. frugiperda .
Murraya koenigii is a plant species with economic and cultural importance in Asian countries. Many studies have shown a wide biopotential of M. koenigii products, including for insect control. Aedes ...aegypti is the main vector of dengue, among other arboviruses. Estimates show that approximately 2.5 billion people are at risk of infection. Attempts at vector control favored the emergence of resistance to available chemical insecticides. Therefore, it is necessary to develop alternative formulations for vector control. This research aimed to evaluate the larvicidal activity of the essential oil from M. koenigii leaves against Ae. aegypti. The death time and bioavailability of the material in aqueous medium, as well as the influence of the type of breeding site on the lethal effect, were investigated. A nanoemulsion was developed as a dispersion system to increase the bioavailability of the essential oil. A test for evaluating the mutagenic potential of Allium cepa meristems was performed as a form of toxicological screening. It was observed that the essential oil from M. koenigii leaves was highly promising in terms of larvicidal activity against Ae. aegypti, both under controlled conditions and in the field. The nanoemulsion showed adequate stability and considerably increased the bioavailability time of the active ingredient in a liquid medium. No genotoxic events were observed in A. cepa cells, but the nanoemulsion showed antiproliferative effects.
•Murraya koenigii is a plant with economic and cultural importance.•Essential oil from M. koenigii was promising larvicidal against Aedes aegypti.•A nanoemulsion EO-based was developed and evaluated in field conditions.•The obtained formulation was effective to keep the EO bioavailable in water.•The formulation proved to be an efficient larvicidal agent to control the dengue vector.
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