Traditional Chemical Pesticides Research Articles

Optimizing the production of dsRNA biocontrols in microbial systems using multiple transcriptional terminators.

Crop pests and pathogens annually cause over $220 billion in global crop damage, with insects consuming 5%-20%of major grain crops. Current crop pest and disease control strategies rely on insecticidal and fungicidal sprays, plant genetic resistance, transgenes, and agricultural practices. Double-stranded RNA(dsRNA) is emerging as a novel sustainable method of plant protection as an alternative to traditional chemical pesticides. Successful commercialization of dsRNA-based biocontrols requires the economical production of large quantities of dsRNA combined with suitable delivery methods to ensure RNAi efficacy against the target pest. In this study, we have optimized the design of plasmid DNA constructs to produce dsRNA biocontrols in Escherichia coli, by employing a wide range of alternative synthetic transcriptional terminators before measurement of dsRNA yield. We demonstrate that a 7.8-fold increase of dsRNA was achieved using triple synthetic transcriptional terminators within a dual T7 dsRNA production system compared to the absence of transcriptional terminators. Moreover, our data demonstratethat batch fermentation production dsRNA using multiple transcriptional terminators is scalable and generates significantly higher yields of dsRNA generated in the absence of transcriptional terminators at both small-scale batch culture and large-scale fermentation. In addition, we show that application of these dsRNA biocontrols expressed in E. coli cells results in increased insect mortality. Finally, novel mass spectrometry analysis was performed to determine the precise sites of transcriptional termination at the different transcriptional terminators providing important further mechanistic insight.

Exploring chemical composition and insecticidal activities of Alpinia calcarata rhizome essential oil against three major storage insects

Alpinia calcarata, generally recognized as snap ginger or lesser galangal of the Zingiberaceae family, undergoes widespread cultivation in tropical nations. It is characterized by its noteworthy pharmacological attributes, such as anti-inflammatory, analgesic, antinociceptive, reproductive, anti-cancer, and gastro-protective effects. Many storage pests now resist traditional chemical pesticides. Transitioning to organic alternatives is a preferable and sustainable solution. This research investigates the insecticidal activity of essential oil from A. calcarata rhizomes, obtained via hydro-distillation. Chemical analysis was conducted, and the study assessed its toxicity and repellent effects on Tribolium castaneum, Lasioderma serricorne, and Callosobruchus chinensis. A yield of 0.4 ± 0.02% essential oil was obtained from dry rhizomes. Gas chromatography-mass spectrometry (GC-MS) characterization revealed the major chemical constituents as 1,8-cineole (25.71%), ethyl iso-allocholate (16.01%), and fenchyl acetate (15.15%). The findings from the investigation into the pesticidal characteristics of essential oils derived from the rhizome of A. calcarata unveiled significant contact (LC50 at 24h was 10.9mg/cm2 for T. castaneum, 1.0mg/cm2 for L. serricorne and 0.5mg/cm2 for C. chinensis) and fumigant toxicity (LC50 at 24h was 4.05mg/L air for T. castaneum, 1.75mg/L air for L. serricorne, and 1.03mg/L air for C. chinensis). The repellent efficacy was evaluated through an area preference test, revealing robust repellent activity at various concentrations. Undoubtedly, the essential oil extracted from the rhizome of A. calcarata is valuable and has the potential to be a safe, organic pesticide for controlling storage pests.

Insecticidal Activity and Molecular Target by Morphological Analysis, RNAseq, and Molecular Docking of the Aryltetralin Lignan Lactone Helioxanthin, Isolated from Taiwania flousiana Gaussen.

Botanical insecticides are considered an environmentally friendly approach to insect control because they are easily biodegraded and cause less environmental pollution compared to traditional chemical pesticides. In this study, we reported the insecticidal activities of the ingredients from Taiwania flousiana Gaussen (T. flousiana). Five compounds, namely helioxanthin (C1), taiwanin E (C2), taiwanin H (C3), 7,4'-dimethylamentoflavone (C4), and 7,7″-di-O-methylamentoflavone (C5), were isolated and tested against the second, third, and fourth instar larvae of Aedes aegypti. Our results indicated that all five compounds showed insecticidal activities, and helioxanthin, which is an aryltetralin lignan lactone, was the most effective with LC50 values of 0.60, 2.82, and 3.12 mg/L, respectively, 48 h after application, with its activity against the second instar larvae similar to that of pyrethrin and better than that of rotenone. Further studies found that helioxanthin accumulated in the gastric cecum and the midgut and caused swelling of mitochondria with shallow matrices and fewer or disappeared crista. Additionally, our molecular mechanisms studies indicated that the significantly differentially expressed genes (DEGs) were mainly associated with mitochondria and the cuticle, among which the voltage-dependent anion-selective channel (VDAC) gene was the most down-regulated by helioxanthin, and VDAC is the potential target of helioxanthin by binding to specific amino acid residues (His 122 and Glu 147) via hydrogen bonds. We conclude that aryltetralin lignan lactone is a potential class of novel insecticides by targeting VDAC.

Plant Protease Inhibitors: A Defense Mechanism Against Phytophagous Insects

In the realm of agriculture, the constant threat of pests and pathogens poses a significant challenge to crop yields. Traditional chemical pesticides, while effective, come with drawbacks such as lack of specificity and the development of resistance. This has spurred a growing interest in exploring alternative methods, with a focus on biodegradable biological control agents and natural products. One promising avenue is the use of Plant Protease Inhibitors (PPIs), which act as a defense mechanism against phytophagous insects. PPIs hinder the activity of insect gut digestive enzymes, leading to reduced protein digestion and impeding the growth and survival of insects. The article delves into the various types of PPIs, their mechanisms of action, and their effectiveness in plant defense. Specifically, it explores the Cystatin Superfamily, with a focus on Family–4 Cystatins known as Phytocystatins. These inhibitors, found in a variety of plants, exhibit potential as biopesticides due to their impact on insect proteolysis. The study also discusses the role of phytocystatins in controlling phytophagous arthropods by targeting their essential digestive proteases. In conclusion, the article emphasizes the significant value of phytocystatins in plant defense and suggests their potential integration as a novel tool in Pest Control Management, highlighting the need for improved policies to enhance their adoption in sustainable agriculture.

Co-Culture of White Rot Fungi Pleurotus ostreatus P5 and Bacillus amyloliquefaciens B2: A Strategy to Enhance Lipopeptide Production and Suppress of Fusarium Wilt of Cucumber.

Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum (FOC), poses a serious threat to cucumber productivity. Compared to traditional chemical pesticides, biological control strategies have attracted more attention recently owing to their effectiveness against pathogens and their environmental safety. This study investigated the effect of white rot fungi Pleurotus ostreatus P5 on the production of cyclic lipopeptides (CLPs) of Bacillus amyloliquefaciens B2 and the potential co-culture filtrate of strains B2 and P5 to control cucumber Fusarium wilt. A PCR amplification of CLP genes revealed that B. amyloliquefaciens B2 had two antibiotic biosynthesis genes, namely, ituA and srf, which are involved in iturin A and surfactin synthesis. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed that CLPs derived from strain B2 contained two families, iturin A (C14, C15) and surfactin (C12-C17). The co-culture exhibited an enhanced accumulation of iturin A and surfactin compared to the monoculture of strain B2. Furthermore, the gene expressions of ituA and srf were both significantly upregulated when co-cultured with the fungus compared to monocultures. In an in vitro experiment, the co-culture filtrate and monoculture filtrate of B. amyloliquefaciens B2 inhibited mycelial growth by 48.2% and 33.2%, respectively. In a greenhouse experiment, the co-culture filtrate was superior to the monoculture filtrate in controlling cucumber Fusarium wilt disease and in the promotion of plant growth. Co-culture filtrate treatment significantly enhanced the microbial metabolic activity and decreased the abundance of FOC in the rhizosphere soil. These results show that the co-culture of P. ostreatus P5 and B. amyloliquefaciens B2 has great potential in cucumber Fusarium wilt disease prevention by enhancing the production of bacterial CLPs.

Nanoemulsions of synthetic rhamnolipids act as plant resistance inducers without damaging plant tissues or affecting soil microbiota.

Plant pathogens and pests can cause significant losses in crop yields, affecting food security and the global economy. Many traditional chemical pesticides are used to combat these organisms. This can lead to the development of pesticide-resistant strains of pathogens/insects and negatively impact the environment. The development of new bioprotectants, which are less harmful to the environment and less likely to lead to pesticide-resistance, appears as a sustainable strategy to increase plant immunity. Natural Rhamnolipids (RL-Nat) are a class of biosurfactants with bioprotectant properties that are produced by an opportunistic human pathogen bacterium. RL-Nat can act as plant resistance inducers against a wide variety of pathogens. Recently, a series of bioinspired synthetic mono-RLs produced by green chemistry were also reported as phytoprotectants. Here, we explored their capacity to generate novel colloidal systems that might be used to encapsulate bioactive hydrophobic compounds to enhance their performance as plant bioprotectants. The synthetic mono-RLs showed good surfactant properties and emulsification power providing stable nanoemulsions capable of acting as bio-carriers with good wettability. Synthetic RLs-stabilized nanoemulsions were more effective than RLs suspensions at inducing plant immunity, without causing deleterious effects. These nanoemulsions were innocuous to native substrate microbiota and beneficial soil-borne microbes, making them promising safe bio-carriers for crop protection.

Cultivable Endophyte Resources in Medicinal Plants and Effects on Hosts.

With the increasing demand for medicinal plants and the increasing shortage of resources, improving the quality and yield of medicinal plants and making more effective use of medicinal plants has become an urgent problem to be solved. During the growth of medicinal plants, various adversities can lead to nutrient loss and yield decline. Using traditional chemical pesticides to control the stress resistance of plants will cause serious pollution to the environment and even endanger human health. Therefore, it is necessary to find suitable pesticide substitutes from natural ingredients. As an important part of the microecology of medicinal plants, endophytes can promote the growth of medicinal plants, improve the stress tolerance of hosts, and promote the accumulation of active components of hosts. Endophytes have a more positive and direct impact on the host and can metabolize rich medicinal ingredients, so researchers pay attention to them. This paper reviews the research in the past five years, aiming to provide ideas for improving the quality of medicinal plants, developing more microbial resources, exploring more medicinal natural products, and providing help for the development of research on medicinal plants and endophytes.

Comparison of toxic effects of 5 macrofungi against Drosophila melanogaster.

Traditional chemical pesticides pose potential threats to human health, the environment, and food safety, and there is an urgent need to develop botanical pesticides that are easily degradable, renewable, and environmentally compatible. This research serves to detect the lethal impacts of Amanita pantherina(DC.:Fr) Schrmm.(Agaricales, Amanitaceae, Amanita), Amanita virgineoides Bas (Agaricales, Amanitaceae, Amanita), Coprinus comatus (O.F.Müll.) Pers. (Agaricales, Psathyrellaceae, Coprinus), Pycnoporus cinnabarinus(Jacq.:Fr) Karst (Polyporales, Polyporaceae, Polyporus) and Phallus rubicundus (Bosc) Fr. (Phallales, Phallaceae, Phallus) on Drosophila melanogaster(Diptera, Drosophilidae, Drosophila), including their effects on lifespan, fecundity, offspring growth and developmental characteristics, antioxidant enzyme activity, peroxide content, and the gene transcription associated with signaling pathways and lifespan of D. melanogaster. The results demonstrated that they all produced lethal effects on D. melanogaster. Female flies were more sensitive to the addition of macrofungi to their diet and have a shorter survival time than male flies. The toxic activity of A. pantherina-supplemented diet was the strongest, so that the D. melanogaster in this group had no offspring. The macrofungal-supplemented diets were able to significantly reduce the activity of antioxidant enzymes, accumulate peroxidation products, up-regulatd the transcription of genes related to signaling pathways, inhibit the expression of longevity genes, reduce the lifespan and fertility of D. melanogaster. Consequently, we hypothetically suggest that medicinal C. comatus, P. cinnabarinus and P. rubicundus hold the potential to be developed into an environmentally friendly biopesticide for fly killing.

Hybrid Fungicides – An Easy Bridge to Trial of Biological Component for Improved Resistance Management and Better Crop Protection

The global search for plant-protection solutions that are both environmentally safe and effective is driven by the need to supply food to the ever-growing world population. The call for chemical load reduction is an important aspect for sustainable agriculture. Toxicity to non-target organisms and negative effects on human health by synthetic agrochemicals have led to a resurgence of interest in 'natural' means of pest and pathogen control, including new sources of biopesticides and botanical pesticides. In addition, there has been increasing pressure concerning the main challenges in crop protection, including better resistance management, regulatory demands, and consumer concerns. The control of plant diseases has depended increasingly on the extensive use of toxic pesticides. Inappropriate and prolonged applications of traditional chemical pesticides lead to environmental damage and adverse health effects. Furthermore, the extensive use of chemical pesticides led to the development of resistance to various plant pathogens. Therefore, improving resistance management is important. Also, consumers, including retail food chains, today demand healthier foods and more sustainable products with less chemical residue. Furthermore, an increasing number of governments and retail food chains have established strictly enforced chemical residue limits. If crops exceed these limits, they will not be allowed to enter these countries and retail food chains. However, there are several barriers to trial of biological products by growers, including the following: a). Biological products have a reputation for not working very effectively. Today there are many biological products that are as effective as synthetic chemicals, but the early impression from years ago remains among many growers, b) growers are very busy with current demands on their time, with most not having the time to learn new biology, reformulate their treatment regime, mixing and testing, and c) general resistance to change. Therefore, a new concept of 'hybrid products', as an easy bridge to trial biological component is suggested. Hybrid fungicides i.e., a combination of a natural product such as Tea Tree Oil (TTO) with broad-spectrum activity and a traditional site-specific chemical can be the 'bridge' between conventional agrochemical farming and sustainable farming. That is because it is a 'pre-mix' and is used in the same way as the grower's current chemical pesticide. Unlike other combinations based on two synthetic chemicals which in most cases have limited mechanisms of action, a premix with a botanical product provides multiple modes of action with an advantage for resistance management.

Strategies for the production of dsRNA biocontrols as alternatives to chemical pesticides.

Current crop pest control strategies rely on insecticidal and fungicidal sprays, plant genetic resistance, transgenes and agricultural practices. However, many insects, plant viruses, and fungi have no current means of control or have developed resistance against traditional pesticides. dsRNA is emerging as a novel sustainable method of plant protection as an alternative to traditional chemical pesticides. The successful commercialisation of dsRNA based biocontrols for effective pest management strategies requires the economical production of large quantities of dsRNA combined with suitable delivery methods to ensure RNAi efficacy against the target pest. A number of methods exist for the production and delivery of dsRNA based biocontrols and here we review alternative methods currently employed and emerging new approaches for their production. Additionally, we highlight potential challenges that will need to be addressed prior to widespread adoption of dsRNA biocontrols as novel sustainable alternatives to traditional chemical pesticides.

Design, synthesis and insecticidal activity and mechanism research of Chasmanthinine derivatives

Unrestricted reproduction and spread of pest had caused great damage to the quality and yield of crops in recent years. Besides the use of traditional chemical pesticides, natural products also make a huge contribution against pests. Chasmanthinine, a diterpenoid alkaloid isolated from Aconitum franchetii var. villosulum, shown extremely antifeedant activity against Spodoptera exigua. Therefore, a series of novel Chasmanthinine derivatives were synthesized and their biological activity was studied in this work. Compound 33 showed the strongest antifeedant activity (EC50 = 0.10 mg/cm2) among all the test compounds. The mechanism research of 33 revealed that its antifeedant effect was related to the inhibition of carboxylesterase (CES), and proved the thiophene acyl group could form a strong binding effect with CES by molecular docking. Moreover, compound 10 exhibited the strongest cytotoxicity (IC50 = 12.87 μM) against Sf9 cell line and moderate contact toxicity. The mechanism research indicated that compound 10 could induce Sf9 cells apoptosis. In summary, the results lay a foundation for the application of diterpene alkaloids in plant protection.

Eco-friendly biosynthesis of silver nanoparticles using Aloysia citrodora leaf extract and evaluations of their bioactivities

In view of their ease of synthesis, stability, functionalization, and low toxicity, biological processes are the excellent choice for the biosynthesis of nanoparticles (NPs). There is potential for NPs in alleviating plant diseases where these nano-sized materials are an ecological alternative to traditional chemical pesticides. Herein, silver nanoparticles (AgNPs) were biosynthesized using the aqueous leaf extract of Aloysia citrodora and were characterized using UV/Vis spectroscopy, transmission electron microscopy (TEM), field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and X-ray diffraction (XRD). The phytochemicals involved in metal ion bioreduction are being identified through Fourier transformation infrared (FTIR). The ensued AgNPs were evaluated for anti-oomycete and antifungal activity against Pythium aphanidermatum, Paecillomyces formosus, Fusarium oxysporum f.sp. cumini, Macrophumina phaseolina, and Botrytis cinerea, wherein they exhibited strong inhibition of the mycelial growth. These findings demonstrated that green AgNPs have the potential to protect plants against phytopathogens under field conditions.

Research Progress on the Synthetic Biology of Botanical Biopesticides.

The production and large-scale application of traditional chemical pesticides will bring environmental pollution and food safety problems. With the advantages of high safety and environmental friendliness, botanical biopesticides are in line with the development trend of modern agriculture and have gradually become the mainstream of modern pesticide development. However, the traditional production of botanical biopesticides has long been faced with prominent problems, such as limited source and supply, complicated production processes, and excessive consumption of resources. In recent years, the rapid development of synthetic biology will break through these bottlenecks, and many botanical biopesticides are produced using synthetic biology, such as emodin, celangulin, etc. This paper reviews the latest progress and application prospect of synthetic biology in the development of botanical pesticides so as to provide new ideas for the analysis of synthetic pathways and heterologous and efficient production of botanical biopesticides and accelerate the research process of synthetic biology of natural products.

Insecticidal Activities Against Odontotermes formosanus and Plutella xylostella and Corresponding Constituents of Tung Meal from Vernicia fordii.

Simple SummaryOdontotermes formosanus (Shiraki) (O. formosanus) and Plutella xylostella (Linnaeus) (P. xylostella) are common industrial and agricultural pests with a wide distribution range, multiple host species, few natural predators, and rapid reproduction. The control of these pests relies heavily on synthetic chemical pesticides; however, environmental pollution and the rise of insect resistance induced by the excessive use of synthetic chemical pesticides pose serious challenges. The present study was designed to systematically evaluate the insecticidal activities of different extracts of tung meal against the above two pests and to reveal the chemical constituents of the main active parts. The result confirmed the remarkable insecticidal activity of tung meal and provided a theoretical basis for its development as a potential plant insecticide.The environmental pollution, pesticide resistance, and other associated problems caused by traditional chemical pesticides with limited modes of action make it urgent to seek alternative environmentally-friendly pesticides from natural products. Tung meal, the byproduct of the detoxified Vernicia fordii (Hemsl.) seed, has been commonly used as an agricultural fertilizer and as a pesticide. However, its active insecticidal extracts and ingredients remain elusive. In the present study, the contact toxicities of tung meal extracts against the agricultural and forest pests like O. formosanus and P. xylostella were examined. Our results showed that ethyl acetate and petroleum ether extracts showed the strongest toxicity against O. formosanus and P. xylostella, respectively. In order to further explore the chemical profiles of the ethyl acetate and petroleum ether extracts, UPLC-Q/TOF-MS and GC-MS analyses have been performed, and 20 and 29 compounds were identified from EA and PE extracts, respectively. The present study, for the first time, verified the noteworthy insecticidal activities on the aforementioned agricultural and forest pesticides and revealed the potential active parts and chemical composition, which are conducive to further exploiting the potential of tung meal as a natural plant-derived insecticide for biological control of agricultural and forest pests.

Inhibitory Potential of a Designed Peptide Inhibitor Based on Zymogen Structure of Trypsin from Spodoptera frugiperda: In Silico Insights

Spodoptera frugiperda (J.E. Smith) is an invasive pest in agriculture. It can potentially damage yield resulting severe crop losses and subsequently significant economic damage each year. S. frugiperda is predominantly managed using traditional chemical pesticides. Accordingly, sustainable alternatives such as digestive enzymes inhibitors can be used as an efficient pest management that protects the environment. This contribution aims to examine the pro-region of S. frugiperda trypsin as specific inhibitor of the pest protease enzyme. Structural modeling in conjunction with molecular docking simulations were conducted to design a peptide sequence with the best docking scores and strong binding energy to the target enzyme. The structural models of six pro-peptides were produced based on modification of 7-amino acids of the pro-region of S. frugiperda trypsin. VERIFY_3D, ERRAT, PROCHECK, PROSA and WHAT-IF scores validated the reliability of the predicted model of S. frugiperda trypsin. Molecular docking studies between the six designed inhibitor peptides and the predicted model structure at three different pH conditions were carried out. Data revealed that VPSNPQR at pH 11.0 with the best docking score, the lowest binding energy (ΔG) and dissociation constant (Kd) indicated a potent binding affinity towards S. frugiperda trypsin’s active site. Moreover, the peptide showed a weak potential for interaction with the human trypsin. The results indicated the importance of computational studies in design and selection of inhibitor peptides against target enzymes. Such inhibitors can be used for S. frugiperda control, which can be further applied in other pest management programs. Docking simulations between the pro-peptide inhibitor and Spodoptera frugiperda midgut trypsin confirmed the capacity of the designed pro-region in inhibiting the insect trypsin.

The Toxicity Effect of Certain Photosensitizing Compounds on Some Biological Aspects of Field Strain of Agrotis ipsilon (Hufnagel) Larvae

The black cutworm, Agrotis ipsilon larvae is the most serious pest around the world; it attacked the plant in the growing stage of many crops such as cotton, potato, corn, and tomato causing great damage for them and others which led to reduce the yield. So many chemical insecticides are used for controlling this pest which may buildup resistance to these pesticides Therefore, it is needed to evaluate some chemical compounds that belonged to different categories such as safranin, methylene blue and bromophenol blue against the 4th larval instars of A. ipsilon using poison baits. The results clearly demonstrated that the tested compounds had, a stomach and contact toxicity through the larval feeding on treated baits also, all these toxicants exhibited antifeedant and starvation effects in addition resulting larval paralysis post-feeding. Results on the basis the medium lethal concentrations LC50 of the tested compounds varied on the larval stage, the promising treatment among the investigated compounds were safranin that showed the lowest LC50, which was more toxic as stomach poison followed by methylene blue and the lowest effect was noticed in case of bromophenol blue treatment. The effect of both LC50 and LC25values of these compounds showed a remarkable significant increase in both larval and pupal durations with retardation in their development as well as an increase in the mortality percentage and the malformation for both the resulting pupae and adults. Also, the toxicants affected the fertility of adults. Therefore, these photosensitizers, compounds can be used for controlling the black cutworm on their hosts as toxic baits’ alternatives to traditional chemical pesticides, for increasing their toxicity and decreasing insect-resistant build up as a method implementing the integrated pest control program.

Sensitivity of phytopathogenic and nodule bacteria of soybeans to microelements preparations obtained by electropulse ablation

Qualitative and quantitative characteristics of soybean yields largely depend on the effectiveness of measures against pathogens caused by phytopathogenic bacteria, which lead to the loss of 30-40% of grain yield. One of the elements of biologization is the use of trace elements in the cultivation of soybeans. The work has been devoted to determining the sensitivity of highly active strains of nodule bacteria and representatives of pathogens of soybean bacteriosis to trace elements preparations Dobrodiy Comfort and Dobrodiy Comfort-Copper, which were obtained by electropulse ablation, and comparing their action with traditional chemical pesticides. For comparison, the drugs of traditional cultivation of soybeans have been used: Rankona, Maxim XL, Rydomil Gold, Propuls. Classical microbiological, phytopathological, statistical method shas been used in the work. In particular, the reliability of the influence of factors has been established by the value of the probability level "p", which was calculated using the program STATISTICA 8. The obtained results have indicated a high sensitivity of yellow pigment pathogens of soybean bacteriosis to preparations Dobrodiy Comfort and Dobrodiy Comfort-copper in native form. The causative agent of angular spot of soybeans has not been sensitive to these compositions. Study have shown that Dobrodiy Comfort and Dobrodiy Comfort-copper are non-toxic to bacteria of the genus Bradyrhizobium and Rhizobium. According to the results of preparations titration, work has been determined that the effect of these preparations on phytopathogens remains in the range of 10-3-10-4. According to the For the first time absence of antibacterial activity at the specified dilution and toxic effect on nodule bacteria, the use of ecological drugs Dobrodiy-Comfort and Dobrodiy Comfort-Copper in the system of soybean protection against bacterial diseases has been analyzed and recommended.

Repellent and Oviposition Deterrent Effect of Bio-rational Green Extracts Against Peach Fruit Fly Bactrocera zonata (Saunders)

The peach fruit fly, Bactrocera zonata S. is a species that can cause important economic losses to various fruit species, with more than 50 host plants. In this study, repellent and oviposition deterrent effects of methanol (Mx), ethanol (Ex) and distilled water (Dx) extracts of moringa bark and leaves, cinnamon, peppermint and ginger were evaluated at different concentrations (10, 20 and 30%) against B. zonata adults. The experiment was carried out by using free choice test. Among all extracts, peppermint (Pm) extracts (Pm-Mx, Pm-Ex and Pm-Dx) delivered important repellent activity at the maximum dosage (30%), i.e. 0.50, 0.75 and 0.50 mean number of adults, respectively; while, the minimum repellent activity was observed in moringa bark of all three extracts. Correspondingly, all extracts have oviposition deterrent effect but Peppermint (Pm) extracts (Pm-Mx, Pm-Ex and Pm-Dx), deliver the best effect. The present investigation revealed that bio-active extracts can be used as alternative cost-effective, safe, and environment-friendly insecticides for the effective management of B. zonata in order to reduce the ecological hazards caused by traditional chemical pesticides.

Extraction of Nitrogen Compounds from Tobacco Waste via Thermal Treatment

Alkaloids, typical nitrogen compounds, were found to be abundant in tobacco waste. The recovery of alkaloids from tobacco waste for biological pesticides could reduce the use of traditional chemical pesticides and avoid the pollution of farmland by the leaching of alkaloids from tobacco waste. Considering the fact that alkaloids can easily volatilize, thermal treatment is expected to be a potential technology to achieve the release and recovery of alkaloids from tobacco waste. For better understanding of conversion behavior of nitrogen-containing compounds in tobacco waste during thermal treatment, purge/trap-GC/MS (gas chromatography mass spectrometry), PY-GC/MS (pyrolysis-gas chromatography mass spectrometry), and fixed-bed/ATD-GC/MS (auto-thermal desorption gas chromatography mass spectrometry) were adopted to detect the ingredients and concentration of nitrogen-containing compounds in tobacco waste and/or volatiles. The results of purge/trap-GC/MS showed that nitrogen-containing compounds in tobacco waste could be effectively evaporated at 180 °C in the forms of N-benzyl-N-ethyl-P-isopropyl benzamide, 2-Amino-4-methylphenol, or N-butyl-tert-butylamine. Specifically, N-benzyl-N-ethyl-P-isopropyl benzamide was the main nitrogenous compound in the volatiles of tobacco wastes accordingly. (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was dominant in N-compounds in pyrolysis condition according to the results of Py-GC/MS. In air atmosphere, with the heating temperature increasing, the concentration of main (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was firstly increased and then decreased. Besides, the interactions between the released volatiles could be accelerated at a high temperature. Accordingly, these findings suggested that pyrolysis under proper conditions could effectively promote the extraction of alkaloids from tobacco waste.

A REVIEW ON FUTURE OF BACULAVIRUSES AS A MICROBIAL BIO CONTROL AGENT

Pesticides driven from Plants, animals, and microbes such as (bacteria fungi, viruses, algae, nematodes and protozoa are replacing traditional chemical pesticides throughout the world. Bio pesticides reduce environmental risks and are target specific. Bio pesticide promotes sustainable agriculture development by reducing the environmental pollution. Various products have been registered and released, that play important role in the agro-market. Regulation of many insect populations in nature happen by Baculoviruses (entomopathogenic viruses). The pesticide based on baculovirus particles has been formed to control pest and their use is beneficial to reduce the risk of synthetic chemical insecticides. The present status and increase use of baculovirus based bio pesticides as replacement of chemical pesticides, its role in integrated pest management, have been discussed in this review.