In Iran, during significant research, the importance of the antagonistic fungus,Talaromyces flavus has been known for the inhibition of the growth of some important plant soil pathogens such as Rhizoctonia solani, Verticillium dahliae and Fusarium oxysporum. Also, according to the results of previous studies, preparation of the above-mentioned fungal bioformulations with substrates in the form of different plantresidues such as rice bran, wheat straw and corn wood was possible and using them in the greenhouse and field, in addition to reducing the incidence of the diseases such as the seedling death, Verticillium and Fusarium wilt in cotton, sugar beet, potato, tomato and greenhouse cucumber, increased yield was also observed. According to the results obtained to this stage of the research, the commercialization of the bioformulation of this fungus is of particular importance. Since the marketing is considered as one of the important factors for the continuation of commercialization, considering the type of bioformulation with easy applications can greatly affect the attraction of relevant consumers and a successful marketing. Therefore, in light of the recent advances in the application of nanotechnology in various sciences, it seems necessary to prepare different nanoformulations of the above biological agent with an emphasis on the ease of use, and study theefficacy in biological control of the plant diseases. In this study, nanoformulations were prepared in two types: nanocapsule (F1 and F3), a type of nanoemulsion (F2), and a type of powder nanoformulation (F4) of T. flavus.
The importance of the Talaromyces flavus antagonistic fungus has been understood for inhibiting the growth of some of the important plant pathogenic agents such as Rhizoctonia solani, Verticillium dahliae and Fusarium oxysporum. Additionally, based on the results of previous research, preparation of the mentioned fungal bioformulation was possible with substrates in the form of various plant residues such as rice bran and wheat straw. The application of this bioformulation in the greenhouse and the field, in addition to reducing the incidence of seedling damping-off, Verticillium wilt and Fusarium wilt diseases in cotton, sugar beet, potato, tomato and greenhouse cucumber, while increases their yields. According to the obtained results, the commercialization of the bioformulation of this fungus has particular importance. Since the marketing is considered to be an important factor in the continuation of commercialization, considering the type of bioformulation with ease of use can greatly affect the attraction of relevant consumers and a successful marketing. Therefore, due to the recent advances in the application of nanotechnology in various sciences, it seems necessary in the further research to investigate different nanoformulations from the biological agent with an emphasis on the ease of use, preparation and their efficacy in biological control of plant diseases. In this study, nanoformulations were prepared in three types: nanocapsule (F1 and F3), nanoemulsion (F2), and nanopowder (F4). Three and six months after production, laboratory experiments on nanoformulations and the formulation based on previous technical knowledge (rice bran and T. flavus) on sporulation and active population of the antagonistic fungus were carried out in a completely randomized design. The results showed that there was a significant increase in sporulation and active population in nanopowder compared to other formulations.
Author: Laleh Naraghi, Maryam Negahban,Asghar Heydari, Mohammad Razavi, Homayoun Afshari-Azad
Keywords: Active Population, Nanoparticle, Talaromyces Flavus, Sporulation
In Iran, during conducting significant research, the importance of Talaromyces flavus antagonistic fungus has been known to inhibit the growth of some of the important soilborne plant pathogens such as Rhizoctonia solani, Verticillium dahliae and Fusarium oxysporum. Also, according to the results of previous studies, preparation abovementioned fungal bio formulation was possible with substrates in the form of various plant residues such as rice bran, wheat straw and corn wood using them in the greenhouse and field, in addition to reducing. The occurrence of diseases such as the seedling death, Verticillium and Fusarium wilt in cotton, sugar beet, potato, and greenhouse tomato and cucumber, increased yield also observed. According to the results obtained to this stage of the research, the commercialization of the bio-formulation of this fungus is very importance. Since the marketing is considered as one of the important factors for the continuation of commercialization, consideration of the type of bio formulation with easy applications can greatly affect the attraction of relevant consumers and a successful marketing. Therefore, in light of the recent advances in the application of nanotechnology in various sciences, it seems necessary in the further research to prepare different nano formulations of the biological agent with an emphasis on the ease of use, and study their efficacy
in biological control of the plant diseases. In this study, we prepared nano-bio-formulations including two types of nanocapsules (F1 and F3), a type of nano emulsion (F2), and a powder type nano formulation (F4) form T. flavus fungus. Three and six months after the production, laboratory tests of nanoformulations were performed in a completely randomized design in terms of the efficiency in inhibiting the colony growth of Verticillium dahliae. The results showed that nanopowder was more effective than other nanoformulations in term of inhibiting the colony growth of the pathogen.
In recent years, different formulations such as nanoemulsions have been widely used for the target delivery, and enhanced biological functions of pesticides combinations. In this study, contact toxicity of Mentha longifolia L. essential oil compared with its nanoemulsion on Ephestia kuehniella Zeller has been investigated. The experiments were conducted and executed at 27±1 C, and 75±5% relative humidity under dark conditions. Chemical composition of this plant extract was also studied. The main constituents were pulegone (28.84%), 1, 8-cineol (19.6%), p-menthan-3-one-cis (8.2%), β-pinene (6.46%) and p-menthan-3-one-trans (5.86%). Results indicated that the mortality rate of 5th instar larva of E. kuehniella increased with rising concentrations (10000-40000ppm) for oil and (8000-20000 ppm) for nanoemulsion, respectively. The essential oil LC50 was 21352ppm, while this value for nanoemulsion was 14068ppm. According to the results, nanoemulsion was more effective than essential oil. M. longifolia oil had lower durability and the 50% persistent time (PT50) was 2.39 day compared to the nanoemulsion (PT50= 17.13 day) in the highest concentration of essential oil. The nanoparticle size was 14-36 nanometers (nm) when the transmission electron microscope (TEM) was applied. The surface morphology of nanoemulsion was also studied by TEM. The average size of the particles was estimated 234nm by using laser light scattering apparatus. The overall results of this study show that by using nanoemulsion formulation, the effect of essential oil contact toxicity and its durability increases. Hence, the nanoemulsion slow-release formulation may represent a new category of biopesticides and this should be considered in the integrated pest management program.
In this study, the nanoemulsion containing Mentha longifolia essential oil was produced by using high-pressure homogenization method and its fumigant toxicity was compared with ordinary M. longifolia essential oil on different stages of Ephestia kuehniella. Experimental conditions were as follows; 27±1 °C, 70± 5% relative humidity in total darkness. Concentrations of 111.1-1111.1 and 62.9- 92.6 μl/l air of oil have been used to control larva and eggs, respectively. Nanoemulsion concentrations were studied at 122.2-1111.1 μl/l air for larvicide experiment and 81.4-114.8 μl/l air for ovicidal stage. PT50 value at 1111.1 μl/l air as a larvicide for nanoemulsion and oil was estimated about 15.18 and 3.69 days, respectively. This value, at 92.6 μl/l air on egg was 14.44 and 2.58 days, respectively. The relative median potency parameter (RMP) showed that there was significant difference between PT50 values of essential oil and its nanoemulsion on both of the two stages of pest. Results showed that nanoemulsion containing M. longifolia oil can release slow properties lead to durability of fumigant toxicity of oil in the long term. Therefore, this new formulation could be considered as a new and ecofriendly biopesticide in pest control.
In this study, the insecticidal activity Artemisia Haussknechtii essential oil, extract and encapsulated form of essential oils in nanoparticles were investigated. Interfacial compression polymerization method was investigated for nano capsules preparation. The effects of emulsifier composition, co-emulsifier, and temperature on the properties of the nanocapsules were investigated. The scanning electron microscopy of particles proved the preparation of nanoparticles. Fumigant toxicity of oil and extract demonstrated fumigant toxicity against Tribolium castaneum and Sitophilus oryza.
It was demonstrated a mortality of 100 percent of Sitophilus oryzae in the concentration of 166ppm. The insecticidal activity varied based on insect species. With the alteration of concentrations of the oil and extracts and exposure time, the variety on fumigant toxicity had shown due to the volatility of extract. The results demonstrated that A. haussknechtii essential oil and its nano-encapsulated form could play a significant role in the formulation of essential oil-based insecticides for the management of stored-grain insects.
The elm leaf beetle, Xanthogaleruca luteolla (Muller) (Chrysomelidae: Coleoptera) is the most important pest of elm tree, causes severe damages on this plant every year. Larvae and adults feed on elm (Ulmus spp.) leaves, defoliate the trees, weakening them and rendering them vulnerable to another pests, diseases and environmental stresses. Chemical control, is used extensively as one of the most important methods of management the pest. Because of deleterious effects of chemical compounds, the use of plant based pesticides would be a safe and proper method for the pest control. Despite of significance of elm leaf beetle in urban landscape, a few studies have been done on the effect of botanical pesticides on it. In this study, the impact of a new botanical pesticide, named Dayabon (EC10%), made from castor oil plant, was evaluated on 2nd instar larvae, 3rd instar larvae and adults for evaluating the damage reduction. To evaluate the damage, 24 hours after insect feeding, leaves were evaluated by Win area apparatus. Treatment of leaves by Dayabon, caused a dramatic damage reduction in the 2nd instar larvae, 3rd instar larvae and adults compared to control, respectively at 5000, 6000 and 4000 ppm. It seems this pesticide causes reduction in insect feeding and so damage on leaves. Also the results showed that the adult stage is more sensitive to Dayabon compared to 2nd instar larvae and 3rd instar larvae. It can be due to the upper amount of their movement and nutrition compared to another stages. Findings of this study indicated the possibility of practical use of Dayabon in management of elm leaf beetle in urban landscape. Considering the hazards of chemical pesticides, production and utilization of botanical pesticides seems a necessity . So it is offered that adequate studies should be done on application of botanical pesticides in order to control the pests in urban landscape and suitable substitute to chemical pesticides should be introduced.
Aphis nerii boyer and Aphis fabae Scop. (Aphididae: Hemiptera) are the pests of some oornamental plants like boxwood and oleander and causes damages on these plants every year. Coccinella septempunctata L. (Coccinllidae: Coleoptera) is one of the most important predators of these aphids which feed of aphids on shoots and leaves, in larval and adult stage. Chemical control is one of the most prevalent methods to control the pest. Because of deleterious effects of the chemical compounds, the use of plant based pesticides would be a safe and proper method for the pest control. In this study, the contact toxicity of a new botanical pesticide, named Dayabon (EC10%, botanical oils), was evaluated on aphids adults, 4rd instar larvae and adult stage of C. septempunctata. A preliminary experiment was conducted to find concentrations to cause 20 and 80% mortality. The bioassay was designed to determine LC50 values at 24 h post treatments. Experiments were performed in three
replicate and five concentrations and survived and dead insects were counted at 24 h post treatments. LC50 values for insects, in concentrations which had a mortality rate between 20 and 80% were calculated using SAS 6.12 software. Also survived insects in test of LC50 determination, kept in separate Petri and were evaluated in term of the rate of reproduction. According to the results, LC50 values were estimated to be 4590 and 4130 ppm for A. nerii and A. fabae, respectively and survived insects show decrease in reproduction compared to control. It seems this pesticide , by effect on the aphids physiology, cause reduction in insect reproduction and so their population on plants. Also the 80% lethal concentration (LC80) of both aphid species, has no impact on mortality of 4rd instar larvae and adult stage of ladybird. Therefore, the usage of 80% lethal concentration to control aphids, will not cause to death of seven-spot ladybird. Considering the harmless of chemical pesticides, production and utilization of botanical and safe pesticides for predators and parasitoids seems a necessary. So it is offered that adequate studies should be done on application of botanical pesticides in
order to control the pests in urban landscape and suitable substitute to chemical pesticides should be introduced.
Nowadays, the use of nano-encapsulation technology of pesticides causes an increase in the efficiency and controlled release of these substances. In this study, the antifeedant and repellent activities of nano-encapsulated formulation (NEF) of wormwood sagebrush Artemisia sieberi Besser essential oil were investigated against the elm leaf beetle Xanthogaleruca luteola (Muller). The experiments were conducted at 25 ± 2 °C, 65 ± 5% RH and a photoperiod of 16:8 h (L: D). NEF decreased the nutritional indices significantly compared to non-formulated oil. NEF at a concentration of 4000 ppm, reduced the efficacy of the conversion of ingested food and the efficacy of the conversion of digested food in larvae, twice lower compared to pure essential oil. The repellency of non-formulated essential oil at a concentration of 8000 ppm reached its highest level after 6 h exposure, while the repellency of NEF increased over time and reached 100% after 24 h and continued for 72 h. Therefore, further investigations are necessary to consider the NEF made by the A. sieberi essential oil as an effective toxicant against the elm leaf beetle.
The elm leaf beetle, Xanthogaleruca luteolla, is the most important pest of elm trees, which causes severe damages every year. Chemical control is used as one of the most important methods of management of the pest extensively. Due to the deleterious effects of chemical pesticides on non-target organisms, beneficial insects and the environment, the use of botanical pesticides would be a safe and suitable method for the pest control. In this study, the contact and feeding toxicity of a new botanical pesticide, named Dayabon (SL10%), was evaluated on the 2nd instar larvae, 3rd instar larvae and adults. A preliminary experiment was conducted to estimate concentrations to cause 20 and 80 percent mortality. The bioassay was designed to determine LC50 values of 24 h post treatments. LC50 of Dayabon was estimated to be 5154, 6272 and 3928 ppm, after spraying (leaf and insect) on the 2nd instar larvae, 3rd instar larvae and adults, respectively. Treatment of leaves caused 20%, 40% and 60% damage reduction in the 2nd, 3rd instar larvae and adults compared with control at 5000, 6000 and 4000 ppm, respectively. Findings of this study indicated the possibility of practical use of Dayabon in management of elm leaf beetle in urban landscape.
Citrus red mite, Panonychus citri McGregor is one of the most important pests of citrus orchards in the world. Due to excessive use of chemical pesticides and development of resistance plus their increasing environmental hazards, the use of essential oils has been highly studied. But the low solubility of essential oils in water, oxidation, in addition to their instability in presence of light, humidity and high temperature has diminished their application. Formulation technology is one of the main strategies that can modify the physical properties and the viability of the essential oils in agricultural est management programs. In this research, the essential oil of Cuminum cyminum L. was encapsulated by in situ polymerization of oil/water emulsion in nano scale and then the effects of nanoencapsulated essential oil (NEO) were analyzed against P. citri. The results showed that LC50 of NEO’s contact toxicity was 743.17 ppm over 24 hours. NEO also affected mortality and decreased oviposition rate in P. citri. NEO had deterrence capacity at 300, 500 and 700 ppm. Moreover, NOE had oviposition deterrence, lowering the number of eggs per female compared to the control. Our finding suggests that high-tech formulations including nanoencapsulation technology can be used as botanical pesticides and as alternatives to chemical pesticides.
Author: M. Bashiri, S. Moharramipour, M. Negahban, SH. Mafi Pashakolaei
Keywords: Citrus red mite, botanical pesticides, pest management, formulation, nanocapsul
New formulations of botanical insecticides have been developed as an effective and safe compound alternative to synthetic pesticides. Application of nanoencapsulated formulations of pesticides enhance efficiency, quality and controlled release of these substances. In this research, insecticidal activity of essential oil of wormwood sagebrush Artemisia sieberi Besser was investigated on various stages of elm leaf beetle Xanthogaleruca luteola (Müller). The experiments were conducted at 25 ± 2 °C, 65 ± 5% RH and a photoperiod of 16: 8 h (L: D). The formulated essential oil was sprayed on leaves and insects simultaneously. The LC50 value of the formulation was 5279, 3939 and 5169 ppm for eggs, larvae and adults, respectively. Treatment of leaves by nanoencapsulated oil at 3000 ppm caused significant reduction at larval stage compared to control. Our findings suggest that the use of nanoencapsulated essential oil can be effective in the management of elm leaf beetle.
Objective: Intraoperative hypothermia is a common problem with anesthesia. Spinal anesthesia, the same as general anesthesia, affects the process of temperature regulation. The aim of this study was to compare the prophylactic effect of intravenous (IV) ondansetron with intrathecal (IT) meperidine on prevention of shivering during spinal anesthesia in patients underwent orthopedic surgery of the lower limb. Methods: In this study, 120 patients with American Society of Anesthesiologists physical status I to II, between the ages 16 and 65 were randomized into three groups. Group O and Group M were given IV ondansetron 8 mg and IT meperidine 0.2 mg/kg, before spinal anesthesia, respectively. Group C received IV saline 0.9%. The core and ambient temperatures, the incidence and intensity of shivering, blood pressure, heart rate, and maximum level of sensory block were recorded.
Findings: Shivering was observed in 15%, 2.5%, and 37.5% of patients in Groups O, M, and C, respectively. There was a significant difference between Group O and M compared to Group C (P = 0.023 for Group O vs. Group C, P < 0.001 for Group M vs. Group C, P = 0.049 for Group M vs. Group O). Shivering incidence and intensity in Group M was significantly lower than Group O (P = 0.049 and P = 0.047, respectively). Twenty‑two patients required additional IV meperidine among which 15 patients were from Group C (37.5%), six patients from Group O (15%) and one patient from Group M (2.5%). Conclusion: We concluded that IT meperidine and IV ondansetron comparably can decrease intensity and incidence of shivering compared to control group as well as decreasing the requirement to additional doses of meperidine for shivering the control without any hemodynamic side effect.
Insect pest management in agriculture is facing challenge in several problems of using synthetic pesticides and toxic fumigants including environmental contamination, pesticide resistance, and destruction of nontarget organisms. So, public and environmental pressure can support environmentally safe pesticide alternatives to the use of synthetic pesticides. In recent years, a new field is developing on the use of botanical pesticide origin in the pest management practices. Botanicals have been considered as potential pest management agents, because they demonstrate to have a wide range of bioactivity and possess contact and fumigant toxicity and repellent, oviposition, and feeding deterrence. In addition, the main advantages of many plant-based pesticides lie in their low mammalian toxicity and rapid degradation with broad-spectrum activity. Botanical insecticides composed of essential oils may prove to be a reasonable alternative to the more persistent synthetic pesticides. The essential oils obtained by the distillation of aromatic plants can be utilized to protect agricultural product pests. Recently, the essential oils and their constituents have received a great deal of attention as pest control agents.
They are volatile and can function as fumigants and, in some instances, are comparable to methyl bromide in laboratory tests with insects. Their action against stored product insects has been extensively studied. Moreover, these natural oil and new formulations are considered to be an alternative means of controlling harmful larvae of field crop insects. Recent research has demonstrated their larvicidal and antifeeding effects, their capacity to delay development and adult emergence and cause egg mortality, their deterrent effects on oviposition, and their arrestant and repellent action. Also the combined effects of gamma radiation or diatome with essential oil on some stored product insect have been reported. Despite these most promising properties, problems related to their volatility, poor water solubility, aptitude for oxidation, and high sorption are the important limiting factors for the application of natural compounds in large-scale commodity fumigations, and it might lead to more residue-treated commodities. In view of the problem, it is necessary to do a kind of research such as work on new formulations of the oil components and their effects on sorption, tainting, and residues in food commodities. Nowadays, using new technologies such as nanoencapsulated formulation can overcome the constraints of plant essential oils. It seems that the findings of research could be promising to make practical use of plant essential oils. As the new technology in nanoencapsuled essential oil through the control release of active ingredients overcome the restrictions of plant essential oils usage in storage and farms. Finally, most of the natural pest control measures using botanicals are becoming important tools by the development of their use in pest management, because they could be economical and eco-friendly for both the public health and the environment.
Recent research has focused on insecticidal property of essential oil plants in biological control of insects. Controlled release by nanoencapsulated essential oil seems to be the best choice for increasing the efficiency and minimization of environmental damage. In this work, efficiency of nanoencapsulated essential oil of Artemisia sieberiBesser was tested on repellent activity of Plutella xylostella L. Several concentrations were prepared and then third instars larvae were introduced into each treatment. Then, repellent activity was determined after 1, 3, 6, 12 and 24 h from commencement of exposure. Results showed that at 1.9 ppm the nanocapule of Artemisia oil was shown here to possess more repellent activity (80%) to P. xylustella compared to Artemisia oil (62%) before formulation after 24h. The repellent activity varied with application method and concentrations and exposure time. The results showed higher repellent rates in nanocapsule than in essential oil due to controlled-release formulations allowing smaller quantities of essential oil to be used more effectively over a given time interval. The reasons for nanocapsulating the essential oil have been to improve its stability to reduce side effects or to reduce dosing frequency and total dosing amount, to obtain better repellent activity, and for sustained (long-lasting) release. Therefore the nanocapsulation of A. sibeiri might provide a new method for the management of P. xylostella.
Author: M Negahban, S Moharramipour, M Zand, SA Hashemi
Keywords: Artemisia sieberi, diamondback moth, essential oil crops, pest arthropods, pest insects
In order to increase the efficiency of essential oils, the use of formulations with controlled release of the oil encapsulated in micro-and nano-scales would be the best option. In this research, the antifeedant activity of nanoencapsulated essential oil of Carum copticum CB Clarke was investigated on Plutella xylostella (L.) larvae. To determine the nutritional indices of the larvae affected by the formulated essential oil, weight of ingested food, larval biomass and weight of feces produced were recorded daily for three days. The experiments were conducted at 27±1 o C, 65±5% RH and photoperiod of 16: 8 h light: dark. Results indicated a significant decrease in nutritional indices such as relative consumption rate, relative growth rate, efficacy of conversion of ingested food and efficacy of conversion of digested food as concentration of the oil increased. Moreover, digestibility was decreased significantly, 72 h after feeding. However, feeding deterrence index was not significantly increased as compared with control. The finding led to a conclusion that nanoencapsulated oil has potential to control release of the essential oils and increase in post-ingestive toxicity of the insect.
Author: M Jamal, S Moharramipour, M Zandi, M Negahban
Controlled release by nanoencapsulated formulations allow the essential oil to be used more effectively over a given time interval, suitability to mode of application and minimization of environmental damage. In this work, efficiency of nanoencapsulated essential oil of Artemisia sieberi Besser was tested on nutritional indices of Plutella xylostella L. Several experiments were designed to measure the indices such as Relative Growth Rate (RGR), Relative Consumption Rate (RCR), Efficiency of Conversion of Ingested food (ECI), Efficiency of Conversion of Digested food (ECD), Approximate Digestibility (AD) and Feeding Deterrent Index (FDI). Treatments were evaluated by the method of leaf disk bioassay at 25°C, 65±5% RH, and a photoperiod of 16:8 h (Light:Dark). Ten third-instar larvae were introduced into each treatment containing different concentrations of the essential oil. Then, ingested food and weight gained were measured after 24, 48 and 72 h intervals. Results showed that nanocapsule of A. sieberi oil was highly effective compared to control (A. sieberi oil), and significantly decreased the RGR ECI, ECD and AD. Moreover, findings indicated a post-ingestive toxicity of the essential oil using the nanoencapsulated formulation. As a result, this nanoencapsulated essential oil tested merits further study as potential insecticide for the control of P. xylostella.
Author: M Negahban, S Moharramipour, M Zandi, SA Hashemi
Various policies and initiatives exist to reduce the effects of chemical pesticides in the environment. Recent research has focused on insecticidal properties of plant essential oils in biological control of insects. Controlled release by nano-encapsulated formulations allows the quantities of the oils to be used more effectively over a given time interval, enhances the suitability to mode of application and minimizes the environmental damage. In this research, the essential oil of Artemisia sieberi Besser was encapsulated by in-situ polymerization of oil/water emulsion in nano-scale. Then fumigant toxicity and persistence of produced nano-encapsuled essential oil (NEO) were examined against Tribolium castaneum (Herbst) and compared with pure essential oil (PEO)(not encapsulated). The fumigant toxicity of nano-capsules (LC50= 11.24 ppm) was significantly higher than that of PEO (LC50= 15.68 ppm). At sub-lethal doses after 7 days exposure, allowed the essential oil to be entrapped without any changes in their composition and control release. Also, the half-life time of the NEO (LT50= 28.73 days) was significantly much longer than that of the PEO (LT50= 4.27 days). Overall, it seems that the findings of present study could be promising to make practical use of plant essential oils. As the new technology in NEO allows the control release of active ingredients, it could be overcome the restrictions of plant essential oils usage in storage and farms.
Author: Maryam Negahban, Saeid Moharramipour, Mojgan Zandi, Seyed Ali Hashemi
In recent decades, use of botanical insecticides has been developed as alternative to synthetic pesticides. Nowadays, use of new technologies such as nano-encapsulated formulation can overcome the constraints of plant essential oils. In this study, nanocapsules of essential oil from Cuminum cyminum L. was prepared by in situ polymerization (O/W) emulation using poly urea-formaldehyde as wall forming material and oil as a core material. The toxic effects of nano-capsules were assessed against Tribolium castaneum (Herbst), as one of the most serious pest of stored products. The fumigant toxicity from nano-capsules (LC50= 16.25 ppm) were highly effective than pure essential oil (LC50= 32.12 ppm) with 7 days of exposure. The influences of surface morphology, wall thickness and diameter on the thermal stability of nano-capsules were investigated. In this study, the nano-capsules basically exhibited good storage stability at room temperature. Our findings show that the nano-encapsulation of C. cyminum oil might provide a new method for management of T. castaneum
In an experiment essential oil extracted from species of the family Myrtacae found in Kashan (center regions of Iran) showed to have potent fumigant toxicity against three major stored-product insects: Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.), and Tribolium castaneum (Herbst). The essential oil was extracted from Eucalyptus leucoxylon. The mortality of 1-7 days old adults of the insect pests increased with concentration from 37 to 926 μl/l air and with exposure time from 3 to 24 h. The LC50 values to the selected essential oil were 2.76 μl/l air, 8.48 μl/l air and 13.51 μl/l air for C. maculatus, S. oryzae and T. castaneum respectively. Fumigant effects of this essential oil were considered to warrant further research into their potential for commercial use.
In order to explore an effective and safe pesticide that could be coupled up with irradiation method, the present study was conducted to determine the synergistic effects of gamma radiation with an essential oil from Perovskia atriplicifolia (Benth) on Tribolium castaneum (Herbst) as a main stored-product pest. Adult insects were exposed to sub lethal doses of gamma radiation and P. atriplicifolia oil, and the mortality was assessed in a short time period after treatment. There was a significant synergistic effect of exposure to gamma radiation and essential oil on 1-7 days old adults of T. castaneum. The potential toxicity of the essential oil on irradiated adults at 900 Gy was synergistically increased. When irradiated adults were exposed to LD5, LD25 and LD50 values of the oil the mortality was increased 8.5, 13.0 and 16.0 times respectively. This combination of irradiation would have a low environmental impact and high compatibility with P. atriplicifolia.
Artemisia sieberi is a widely distributed plant in Iran. Because some species of Artemisia are insecticidal, experiments were conducted to investigate fumigant toxicity of the essential oil. Dry ground leaves were subjected to hydrodistillation using a modified Clevenger-type apparatus and the resulting oil contained camphor (54.7%), camphene (11.7%), 1,8-cineol(9.9%), β-thujone (5.6%) and α– pinene (2.5%).
The mortality of 7 days old adults of Callosobruchus maculatus, Sitophilus oryzae, and Tribolium castaneum increased with concentration from 37 to 926 μL/L and with exposure time from 3 to 24 h. A concentration of 37 μL/L and an exposure time of 24 h was sufficient to obtain 100% kill of the insects. Callosobruchus maculatus was significantly more susceptible than S. oryzae and T. castaneum; a second more detailed bioassay gave estimates for the LC50 of C. maculatus as 1.45 μL/L, S. oryzae 3.86 μL/L and T. castaneum16.76 μL/L. These results suggested that A. sieberi oil may have potential as a control agent against C. maculatus, S. oryzae and T. castaneum.
Three essential oils extracted from the species of the family Myrtaceae found in Kashan (centre regions of Iran) were shown to have potent fumigant toxicity against three major stored‐product insects: Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). These were the essential oils from Eucalyptus intertextaR.T. Baker, Eucalyptus sargentii Maiden and Eucalyptus camaldulensis Dehnh. The mortality of 1‐ to 7‐day‐old adults of the insect pests increased with concentration from 37 to 926 μl/l air and with exposure time from 3 to 24 h. The LC50 values to the selected essential oils were between 2.55 and 3.97 μl/l air for C. maculatus, 6.93 and 12.91 μl/l for S. oryzae and 11.59 and 33.50 μl/l air for T. castaneum. Fumigant effects of these essential oils were considered to warrant further research into their potential for commercial use.
In regard to the invasion of various food commodities by insects and harmful effects of chemical pesticides, essential oils are among the best known substances tested against stored product pests. Effects of essential oils from Artemisia sieberi Besser and Artemisia scoparia Waldst et Kit were tested against oviposition deterrence, egg hatching and first instar larvae of Callosobruchus maculatus F. at 27±1 o C and 65±5% RH under dark condition. For each essential oil, five replications were conducted. Increasing the essential oil concentrations resulted in increase if insecticidal activity of essential oils on eggs, first instar larvae and oviposition deterrence. At 0.14 m L/g food, the essential oils of A. sieberi and A. scoparia resulted in inhibition of oviposition of the insect. The maximum concentration of essential oils (2.86 m L/L air) caused 100% mortality of first instar larvae. Although, oviposition deterrence of A. scoparia was stronger than A. sieberi, however, ovicidal and larval mortality caused by both essential oils were not significantly different. LC 50 values indicated that essential oil of A. scoparia with 1.11 and 1.06 m L/L air against eggs and first instar larvae do not have significant difference with A. sieberi. It was found that plant essential oils can be used as a safe pesticide or odel for new synthetic pesticides to control stored pests.
Repellent activity and persistence of essential oil of Artemisia sieberi Besser were investigated against three stored product insect species Callosobruchus maculatus F, Sitophilus oryzae L. and Tribolium Castaneun Herbst at 27±1 C, 65±5% R. H under dark condition. In this study, dry ground leaves were subjected to hydrodistillation using a modified clevenger-type apparatus. On the basis of the LT 50s, C. maculatus was killed faster than S. oryzae and T. castaneum. Also, persistence or half-life time of the oil for C. maculatus was significantly longer than S. oryzae and T. castaneum. However, the essential oil was significantly more repellent to T. castaneum than S. oryzae and C. maculatus. These results demonstrated the efficacy of A. sieberi oil for applying in organic food protection.
Efficiency of essential oils from Artemisia sieberi Besser and A. scoparia Waldst et Kit on nutritional indices of Tribolium castaneum Herbst was tested in this study. Several experiments were designed to measure the indices such as relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrent index (FDI). Treatments were evaluated by the method of flour disk bioassay in the dark, at 27±1 o C and 65±5% RH Several concentrations of 0, 0.1, 0.5, 0.75, 1, 1.5 and 2 m L/disk were prepared from each essential oil and 10 adult insects were introduced into each treatment. Then, ingested food and weight gained were measured three days later. Results showed that A. sieberi oil was highly effective compared to A. scoparia, and significantly decreased the RGR and RCR. Moreover, in higher concentration (2 m L/disk), the ECI (9.81%) was significantly low. The A. sieberi oil was more effective on FDI than A. scoparia.
Author: M Negahban, S Moharramipour
Keywords: Essential Oil, Tribolium Castaneum, Relative Growth Rate, Relative Consumption Rate, Efficiency Of Conversion Of Ingested Food, Feeding Deterrent Index
Chemical composition of the essential oil from Artemisia scoparia Waldst et Kit, and its fumigant and repellent activity were investigated against three stored product insects, Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.), and Tribolium castaneum (Herbst). Dry ground leaves were subjected to hydrodistillation using a modified clevenger-type apparatus and the chemical composition of the volatile oil was studied by GC-MS. Nineteen components (99.51% of the total composition) were identified. β-Pinene (19.01%), capillin (17.45%), limonene (15.11%), myrcene (10.95) were found to be the major constituents of the oil. The mortality of 1-7 day old adults of the insect pests increased with concentration from 37 to 926 μL per L air and with exposure time from 3 to 24 h. A concentration of 37 μL per L air and exposure time of 24 h was sufficient to obtain 100% kill of the insects. Callosobruchus maculatus was more susceptible than S. oryzae and T. castaneum. A second more detailed bioassay gave estimates for the LC50 of C. maculatus as 1.46 μL per L air, S. oryzae 1.87 μL per L air and T. castaneum 2.05 μL per L air. Also, the essential oil was significantly more repellent to T. castaneum and S. oryzae than C. maculatus. However, half-life time of the oil for C. maculatus was longer than S. oryzae and T. castaneum. These results show the efficacy of A. scoparia oil for use in organic food protection.
Atremisia sieberi Besser is a widely distributed plant that grows in many areas of Iran and has strong insecticidal activity against stored product pests, so an experiment was conducted to investigate fumigant toxicity of the A. sieberi oil collected from Karaj region of Iran. The oil was applied against one to seven day old adults of three major stored product insects including: allosobruchus maculatus (Fab.), Sitophilus oryzae (L.), and Tribollium castaneum (Herbst). The potency of fumigant toxicity of A. sieberi on C. maculatus was higher (LCso: 1.64 IJ.L per L) than S. oryzae (LCso: 4.41 IJ.L per L) and T. castaneum (LCso: 20.31 IJ.L per L). The relationships between the time exposure and oil concentration on mortality show that the mortality was increased as oil concentration and exposure time was increased. The concentration of 185 IJ.L per L and exposure time of 24h was enough to obtain 100% kill of the insects. It was also found that the regions where A. sieberi grows affect essential oil components of the plant and can play an important role in properties of fumigant toxicity.
Atemisia scoparia (Compositae) is a widespread plant growing wild in many regions of Iran. Extracts from this plant are commonly used as flavoring agent in the food industry, and are recognized as an antihelmintic, stomachic and tonic-bitter. However, its insecticide activity is not reported yet. Most of this substance has lower mammalian toxicity and low persistence in the environment. The essential oil obtained from dry ground leave of A. scoparia, was subjected to hydrodistillation using a modified Clevenger-type apparatus, and was tested against one to seven days old adults of Tribolium castaneum at different concentrations ranging from 3.7 x 10-4 to 0.9 µl/cm 3. The experiment was conducted with five replications in growth chamber at 25±1 C and 65±5% RH in dark condition. The mortality was recorded at several time intervals (3-48h). Fumigant toxicity of the essential oil for all tested treatments was found to increase as its concentration and time were increased. LC50 value after 12h was found 0.2 µl/cm 3 and LT50 value at the concentration of 0.3 µl/cm 3 was 8.46 h. At the concentration of 0.9 µl/cm 3 the mortality was attained 100% after 12 h. It was observed that the essential oil of A. scoparia contains sources of biological active vapors that are potential efficient insecticide. Consequently, the possibility of employing this natural fumigant to control stored product insects may be worthy of further investigation.
Author: M Negahban, S Moharramipour, M Yousefelahi