Traditional Chemical Pesticides Research Articles

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.

A homoisoflavonoid and a fatty acid in common purslane (Portulaca oleracea L.) synergistically inhibit growth of Spodoptera litura larvae.

Portulaca oleracea L., common purslane, is an insecticidal plant that has been documented as a 'Chinese indigenous pesticide', and it is seldom visited by insects in the field. However, identification of anti-insect compounds and mechanisms of action are still unclear. Interplanting purslane with Chinese cabbage demonstrated that purslane may contain secondary compounds that S. litura avoids eating. Four compounds were isolated from P. oleracea by directed anti-insect activity, and their chemical structures were identified by NMR spectra as (9Z,11E,15Z)-13-hydroxyoctadeca-9,11,15-trienoic acid (1), portulacanone A (2), portulacanone D (3), and a new natural product 2,4'-dihydroxy-3',5'-dimethoxychalcone (4). A combination of compound 1 and 2 possessed stronger activity than other combinations (compounds 1 + 3; 1 + 4; 2 + 3; 2 + 4; 3 + 4). Both active compounds were detected in all samples from 23 regions in China, and concentrations in samples collected from 17 regions were generally above 500 μg/kg. Concentrations of compounds 1 and 2 fluctuated greatly from April to November, and reached maximum concentrations of 45 951.44 μg/kg for compound 1 and 3739.09 μg/kg for compound 2 in November. The combination of these compounds (1 + 2) caused mid-gut structural deformation and tissue decay as determined by mid-gut histopathology of S. litura. In general, these active compounds coexisting contributed to partly protect purslane from insects. This research also provides new insights into the use of purslane as important ingredient of botanical pesticide alternatives to traditional chemical pesticides. © 2019 Society of Chemical Industry.

A Novel Densovirus Isolated From the Asian Tiger Mosquito Displays Varied Pathogenicity Depending on Its Host Species.

Mosquito-borne viral diseases (MBVDs) continue to pose a significant global public health burden. Mosquito control remains a core intervention strategy in integrated mosquito management (IMM) programs to reduce the transmission of MBVDs. Mosquito densoviruses (MDVs) are mosquito-specific entomopathogenic viruses, and their attractive biological and pathogenic characteristics make MDVs potential biological control agents as alternatives to traditional chemical pesticides. However, different viral strains vary greatly in their pathogenicity against different mosquito species, which poses an obstacle for the wide application of MDVs in vector control. In this study, a novel MDV, Aedes albopictus densovirus-7 (AalDV-7), was isolated from field-collected Aedes albopictus in the dengue-endemic area of Guangzhou, China. The complete 4,048 nt genome of AalDV-7 was cloned and sequenced, and the transcription and translation of three open reading frames (ORFs) were characterized. Phylogenetic analysis indicated that AalDV-7 clustered with MDVs mostly isolated from indigenous mosquitoes. The pathogenicity of AalDV-7 to A. albopictus, Aedes aegypti, and Culex quinquefasciatus larvae was completely different, and the median lethal dose (LD50) of AalDV-7 in A. albopictus which was 109.48 genome equivalents per ml (geq/ml) was 12 and 46 times lower than those in A. aegypti (1010.56 geq/ml) and C. quinquefasciatus (1011.15 geq/ml). Furthermore, the median lethal time (LT50) value in A. albopictus (7.72 days) was 25% and 26% shorter than those in A. aegypti (10.24 days) and C. quinquefasciatus (10.42 days) at a titer of 1011 geq/ml. Furthermore, the mortality of AalDV-7-infected mosquitoes increased in a dose-dependent manner, and the highest mortality was found in A. albopictus larvae exposed to 1011 geq/ml AalDV-7 (82.00%). Sublethal effects analysis also showed that AalDV-7 infection significantly decreased pupation and emergence rates. The 1st–2nd instar larvae of all three mosquito species showed a near 100% infection rate, and the highest relative vial titer (305.97 ± 67.57 geq/ng) was observed in the 1st–2nd instar larvae of C. quinquefasciatus. These pathogenic characteristics make AalDV-7 a potential MBVDs control agent in China, whereas its negligible pathogenicity and high infection rate and viral dose in vivo make it a good candidate for gene delivery vectors in C. quinquefasciatus gene function analysis. In conclusion, the continuous discovery and isolation of new MDVs enrich the pool of mosquito entomopathogenic viruses and provide a variety of choices for optimal MDVs or combinations of MDVs to target certain mosquitoes.

Mixed culture fermentation between Rhizopus nigricans and Trichoderma pseudokoningii to control cucumber Fusarium wilt

Fusarium wilt, caused by Fusarium oxysporum, is a devastating soilborne fungal disease. Compared to traditional chemical pesticides, biological control has been attracting increasing attention recently, owing to its eco-friendly features. This study investigated the potential use of mixed culture fermentation of Rhizopus nigricans and Trichoderma pseudokoningii (MCF) to control Fusarium oxysporum f.sp.cucumerinum (FOC). At first, the tablet confrontation experiment using bio-control fungi and F. oxysporum showed that the suppression rate of R. nigricans and T. pseudokoningii were more than 60% higher than that of individual fermentations. Furthermore, the inhibitory effect of MCF on the pathogen was higher than that of single fermentation broth, both in vitro and in greenhouse experiment. At the molecular level, MCF had better control on the number of pathogens in the plant tissue and soil, as seen by the real-time PCR assay. In the pot experiment, increased activities of the defense enzymes involved in PAL, SOD, and POD indicated that mixed broth treatment could increase the plant-induced resistance. In the field experiment, after two-year treatment by the mixed broth, the relative control effect on cucumber Fusarium wilt was 76.5%. Through this study, we demonstrated that co-fermentation of R. nigricans and T. pseudokoningii has synergistic effect on the control of F. oxysporum, which may promote more reasonable and effective utilization of biocontrol agents in future.

Current developments in the production of fungal biological control agents by solid-state fermentation using organic solid waste

Biological control agents are slowly and steadily replacing traditional chemical pesticides. Among them, fungal entomopathogens have assumed a key role in controlling a growing number of pests. Research on fungal entomopathogens has expanded constantly during the last decades, confirming real interest in their biocontrol potential. The production of fungal entomopathogens by solid-state fermentation has arisen as a sustainable production method, which is slowly becoming preferred over submerged fermentation considering the advantage of using of agro-industrial wastes as substrates. This review discusses relevant studies on fungal entomopathogens, with a special interest in their production as biocontrol agents by solid-state fermentation processes, including reactors used and operational conditions, focusing mainly on the two most-used fungal entomopathogens worldwide, Beauveria spp. and Trichoderma spp.

Antimicrobial Activity and Chemical Composition of Three Essential Oils Extracted from Mediterranean Aromatic Plants.

There is a growing interest in essential oils (EOs) as possible alternatives for traditional chemical pesticides. This study was carried out to characterize the chemical composition of the three EOs extracted from Verbena officinalis, Majorana hortensis, and Salvia officinalis using gas chromatography (GC) and GC-mass spectrometry (GC-MS) and to evaluate in vitro their efficacy against some phyto or human pathogens. The antifungal activity was investigated against Colletotrichum acutatum and Botrytis cinerea in comparison with Azoxystrobin as a large spectrum fungicide. Antibacterial activity was evaluated against Bacillus megaterium, Bacillus mojavensis, and Clavibacter michiganensis (G+ve) and Escherichia coli, Xanthomonas campestris, Pseudomonas savastanoi, and P. syringae pv. phaseolicola (G-ve) compared to a synthetic antibiotic tetracycline. Minimum inhibitory concentration was evaluated against the above tested fungi using 96-well microplate method. Results showed that the chemical structure of the three studied EOs was mainly composed of monoterpene compounds and all oils belong to the chemotype carvacrol/thymol. Results of GC analysis identified 64 compounds, which were identified based on their mass to charge ratio. Furthermore, the different concentrations of studied EOs inhibited the growth of tested microorganism in a dose-dependent manner.

Study on botanical pesticides and its application in production of traditional Chinese medicine

The issues including excessive pesticide residues and heavy metal contamination have become the bottle-neck in the development of Chinese herbal medicines. Compared with traditional chemical pesticides, biological pesticides, especially botanical pesticides, are more safe and environment-friendly, which were beneficial to the quality improvement Chinese medicinal materials. Though there exists a weak basic research and it is hard for promotion and regulation, the policy of good and the desire for botanical pesticides will accelerate its development, and replace traditional chemical pesticides gradually. This paper reviews the current situation of botanical pesticides, and gives some pertinence suggestions according to the existing problems and challenges. Research on botanical pesticides will become the key point to solve the problem of excessive pesticides residues and heavy metal contamination, and promote the healthy development of Chinese materia medica.

Insect Trapping Method Based on Progressive Star Network

This paper proposes an insect trapping method based on progressive star network. There are two steps: Firstly, construct the network; secondly, trap insects through the network. The network is constructed as following descriptions: 1. Confirm the density of light node. 2. Adjust the height of light node versus growth of crops/plants. This paper contributes to relevant studies in that it proposes a new star network, in which the height of light node changes according to the growth of crops or plants, makes full use of biological resources and avoids bad consequences that traditional chemical pesticides bring about. The star network proposed is simple, reliable and successfully avoids redundant data resulted from frequency communication

BIODIVERSITY OF ENDOPHYTIC BACTERIA AS A PROMISING BIOTECHNOLOGICAL RESOURCE

Abstract Endophytic called bacteria are those colonizing the internal tissues of plants without caus-ing disease and not rendering negative influence on its development. There are great prospects for search, selection and study of new species of endophytic bacteria, improving the development of plants, with the aim of creating new microbial preparations for adaptive crop production. Since bac-terial endophytes colonize the same ecological niches in the plant as phytopathogenic microorgan-isms, they are a promising agent for biocontrol of phytopathogens. Classical studies of biodiversity of endophytic bacteria based on a characterization of isolates obtained from internal plant tissues after surface sterilization. Endophytic bacteria are able to improve phosphorus nutrition of plants, to pro-duce IAA and siderophores. It is shown that endophytic bacteria are capable of producing vitamins, have a number of additional properties necessary for the improvement of plant development, such as: regulation of osmotic pressure, regulation of stomata, modification of root development of plants, regulation of nitrogen nutrition of plants. Endophytic bacteria are able to reduce or prevent the negative effects of pathogenic microorganisms on plants. Inoculation of plants by endophytic bacteria is able to significantly reduce the harm caused to plants by pathogenic fungi, bacteria, viruses, insects and nematodes. Unique strains of endophytic bacteria can be used directly for inoculation of seeds or seedlings, reducing, thus, the influence of biotic and abiotic factors on the plant, due to the active colonization of internal tissues of plants and subsequent positive biochemical and physiological effect on the plant. While in endosphere, endophytes have a significant advantage over organisms that live in the rhizosphere and phyllosphere due to the stable pH, humidity, flow of nutrients and lack of competition from a large number of microorganisms. For the inoculation of plants with endophytic bacteria do not require large amounts of inoculum, taking into account high specificity of such plant-microbe symbiosis and competitiveness of endophytic bacteria. This technique can be very at-tractive for biotechnological productions, seeking the replacement of traditional chemical pesticides. Keywords: endophytic bacteria, biodiversity, plant-microbial interaction, plant growth promotion biocontrol, secondary metabolites, the genome of bacteria, microbial preparations.

Field efficacy of expanded polystyrene and shredded waste polystyrene beads for mosquito control in artificial pools and field trials, Islamic Republic of Iran

Concerns about traditional chemical pesticides has led to increasing research into novel mosquito control methods. This study compared the effectiveness of 2 different types of polystyrene beads for control of mosquito larvae in south-east Islamic Republic of Iran. Simulated field trials were done in artificial pools and field trials were carried out in 2 villages in an indigenous malaria area using WHO-recommended methods. Application of expanded polystyrene beads or shredded, waste polystyrene chips to pool surfaces produced a significant difference between pre-treatment and post-treatment density of mosquitoes (86% and 78% reduction respectively 2 weeks after treatment). There was no significant difference between the efficacy of the 2 types of material. The use of polystyrene beads as a component of integrated vector management with other supportive measures could assist in the control of mosquito-borne diseases in the Islamic Republic of Iran and neighbouring countries.

Larvicidal Activity Of Plant Oil Formulation Against Three Important Vector Mosquito <italic>Sp</italic>.

Over a last few decades, there has been increasing interest in isolating biological substances against various diseases. Of which mosquitoes plays a vital role in transmitting numerous diseases that are harmful to human being (malaria, filariasis and numerous viral diseases, such as dengue, Japanese encephalitis and yellow fever). Mosquitoes are also become increasingly resistant to traditional chemical pesticides and there is growing concern about the potential health and environmental risks surrounding these products. In order to overcome this, efforts have been taken to control the mosquito by using biological substances . In the present study plant oil formulation was used to control the mosquito larvae. The efficacy of different concentration of the plant oil formulation viz. 15.62, 31.25, 62.5, 125.0 and 250.0 ppm for their larvicidal activity against Ae. aegypti, An. stephensi and C. quinquefasciatus. These results are very promising in creating new effective and affordable approaches to the control of vector mosquitoes.

Recovery and purification of thuringiensin from the fermentation broth of Bacillus thuringiensis

Thuringiensin is a heat stable β-exotoxin from Bacillus thuringiensis with a great potential for replacing the traditional chemical pesticides. A process using micellar-enhanced ultrafitration method to recover thuringiensin was significantly improved by the use of a spiral-wound membrane, which could be operated at a low transmembrane pressure drop. This method was performed by adding a surfactant cetylpyridinium chloride (CPC) into the fermentation broth. After the surfactant-thuringiensin conjugates were formed, the broth then passed through the ultrafiltration membrane and the retentate was collected. The results indicated the optimal concentration of CPC for producing a maximal recovery up to 99.3% is 4%. For purification, the centrifuged broth was further filtered by a membrane filter. The filtered solution then was mixed with 50% of activated carbon. The supernatant then was injected into a preparative HPLC. The eluate was collected during thuringiensin peak formation. This eluate was then concentrated by vacuum evaporation and dialysis using an electrodialyzer to remove the excess salts. The dialyzed solution was then crystallized by lyophilization. The purity of the thuringiensin crystal was identified by HPLC, capillary electrophoresis, and mass spectrometry.

Sandoz Crop Protection Prepares for Changing Agrochemicals Industry

Public attitudes toward agricultural chemical producers may be at an all-time low. Whether deserved or not, companies must operate in an environment that has become largely hostile to their business. Fears for health and safety have made chemical pesticide products increasingly unwelcome. (Observers suggest that the industry's future will depend not just on a change in image, but rather on a change of business perspective to address environmental and safety concerns of customers, regulators, and the public while still producing effective products. Sandoz Crop Protection, the four-year-old U.S. subsidiary of Sandoz Ltd. of Basel, Switzerland, is moving in this direction. Based in Des Plaines, III., the company manufactures a broad variety of both traditional chemical pesticides and biological pest control agents. Formed from the merger of Velsicol Chemical's agrochemical business, acquired from Farley/Northwest Industries in 1986, and Sandoz's Zoecon subsidiary, Sandoz Crop Protection became the North Amer...

Pheromones: Their potential role in control of agricultural insect pests

Serious side effects from the conventional use of traditional chemical pesticides for routine arthropod pest management have prompted the investigation and development of alternate strategies for the minimization of pest damage. Insect sex pheromones have been proposed as a potential group of alternative control agents for over twenty years. The possible uses of these substances for insect control are discussed and factors influencing their development for pest management are presented. The scientific research and commercial development of oriental fruit moth mating disruption is presented as a case study for the commercialization of this approach. Advantages and limitations of pheromone-based control tactics are presented. Mating disruption technology is starting to find its place in a number of diverse cropping situations. The use of pheromones for pest control promises to be an important component of the ongoing challenge to develop alternatives that may help to solve major environmental and human health problems associated with chemical pesticide use in agriculture.