Insecticides Research Articles

Amelioration of Quinalphos-Induced Oxidative Stress by Emblica officinalis Fruit Extracts in Rats

The fruit of Emblica officinalis (commonly known Amla) contain potent antioxidants and is most commonly used in the Ayurveda for the treatment of various diseases. Quinalphos- a organophorus insecticide is known to alter antioxidant defense system in mammals. With this premise, experiment was planned with objective to study the effect of amla fruit extract supplementation on quinalphos induced oxidative stress. Twenty-four Sprague-Dawley rats were homogenously divided into six groups of four animals each. Group I was kept as control. Group II was orally given quinalphos at the dose rate of 2 mg.kg -1 . day -1 . Group III and V were orally gavaged with amla in sugar and honey bases respectively at the dose rate of 50 μg.kg -1 .day -1 whereas group IV and VI were orally dosed with quinalphos along with amla in sugar and honey bases respectively at above mentioned dose rates from day 16-45. The various indices of antioxidant status were analyzed in major organs of treatment groups viz . Liver, kidney and brain. Sub chronic quinalphos administration produced oxidative stress in rats as evidenced by increase in lipid peroxidation, glutathione peroxidase and decline in superoxide dismutase. Oral supplementation of amla extract in sugar and honey bases provided partially amelioration against altered antioxidant status following sub chronic quinalphos exposure. Results of histopathological study were also in corroboration with blood antioxidant status validating amla in either bases was unable to provide full protection against quinalphos induced toxicity in rats.

The bitter battle over the world's most popular insecticides.

As regulators consider a ban on neonicotinoids, debate rages over the harm they cause to bees.

Toxicities of 26 pesticides against 10 biological control species

To determine selective effectiveness for specific pesticides on biological control species we evaluated the contact toxicity of 16 insecticides, 2 acaricides, 3 fungicides, and 5 biopesticides. Targeted species included 3 predatory mites (Phytoseiulus persimilis Athias-Henriot, Amblyseius swirskii Athias-Henriot, and Neoseiulus californicus McGregor), 5 hymenopteran parasitoids (Diglyphus isaea Walker, Aphidius colemani Viereck, Encarsia formosa Gahan, Eretmocerus eremicus Rose and Zolnerowich and E. mundus Mercet), and 2 hemipteran predators (Orius laevigatus Fieber and Nesidiocoris tenuis Reuter) in laboratory condition. In addition, residual toxicity was evaluated on P. persimilis, E. formosa, and O. laevigatus. For contact toxicity, five insecticides (spinetoram, spinosad, lepimectin, chlorfenapyr, and dinotefuran+spinetoram) showed high toxicity to predatory mites. Most pesticides tested were highly toxic to all hymenopteran species except for D. isaea which showed low susceptibility to 11 pesticides. Bistrifluron+flubendiamide and B. valismortis were less toxic to A. colemani, and only B. valismortis was safe to both E. mundus and E. eremicus. Insect growth regulators (methoxyfenozide and bistrifluron), chlorantraniliprole, and bistrifuron+flubendiamide were not toxic to hemipteran predators. Fungicides and biopesticides were safe to hemipteran predators except for two biopesticides (B. subtilis and P. fluorescens). Most pesticides had low residual toxicity to P. persimilis, with the exception of chlorfenapyr whose toxicity persisted over 7days. One insecticide (cyantraniliprole), 2 acaricides (spiromesifen and fenpyroximate), 1 fungicide (metrafenone), and 4 biopesticides (B. subtilis, P. polymyxa, P. fluorescens, and B. valismortis) showed a much lower residual toxicity to E. formosa. Eight insecticides, 2 acaricides, 3 fungicides, and 5 biopesticides showed low residual toxicity to O. laevigatus.

Impact of new insecticides on parasitization efficiency of Trichogramma chilonis Ishii

Impact of new insecticides on parasitization efficiency of Trichogramma chilonis Ishii

Histological effect of methomyl on rat brain and testis

Methomyl is a highly toxic carbamate insecticide and is used on a wide variety of crops. Prolonged exposure to these pesticides is known to cause teratogenic effect and decreased fertility in experimental animals. For this purpose, the present study was designed to investigate the effect of methomyl on the histological structure of brain and testes of male rats. Twenty four adult rats weighing about (250 – 300) gm and (8-10) weeks of age were used in this study, divided into four groups, six rats per group, first group serves as a control and three other groups were administered methomyl orally at three different doses (0.5 mg/kg B.W., 1 mg/kg B.W. and 2 mg/kg B.W.). At the end of the experiment period, the rats anesthetized and sections from brain and testes were prepared to investigate the histological effects of this insecticide. Various degrees of histological change in the structure of the brain and testes were observed in comparison with the control group. This alteration included degeneration of the nerve cells in the cerebrum and abnormal purkinje cells in the cerebellum with different degrees of valuation were seen, also the section from the seminiferous tubules of methomyl treated rats showed a reduction in the population of mature sperm cells, wider luminal diameter and decrease in leydig cells number in the interstitial spaces. These effects could impair the fertility potential of male

Clinical study of the therapeutic efficacy from different dosages of pralidoxime chloride used in patients with acute organophosphorus pesticide poisoning

Objective To investigate the effect of different doses of pralidoxime chloride on clinical outcome including recovery rate and mortality in patients with acute organophosphorus pesticide poisoning. Methods According to the total amount of pralidoxime chloride administered over the first 24 hours or entire duration of hospitalization, a cohort of 163 organophosphorus pesticide poisoning patients, admitted from February 2004 to December 2014 were assigned to different groups followed by a retrospective analysis. Comparisons of recovery rate, mortality rate, mean length of hospital stay, and duration of mechanical ventilation were made among groups. SPSS 18.0 was used to analyze categorical variables between the data of groups with χ2 test/Fisher exact probability method and numerical variables with t test or One-way ANOVA, and statistical significance was set as P<0.05. Results According to the amount of pralidoxime chloride given over the first 24 hours, the recovery rate and the mortality rate were significantly improved in the experimental group (pralidoxime chloride>2 g) than in the control group (pralidoxime chloride 4 g) (P=0.034). Based on the total amount of pralidoxime chloride prescribed in the entire duration of hospital stay, the recovery rate and mortality rate were significantly better in the experimental group than those in control group (P=0.002), and among the three dose-response subgroups, the significant difference in recovery rate and mortality rate were also observed (P=0.006). Conclusions Increased amounts of pralidoxime chloride prescribed in the first 24 hours and in the whole hospitalized period can improve the recovery rate and reduce the mortality rate in organophosphorus pesticide poisoning patients. Key words: Acute organophosphorus pesticide poisoning; Insecticide; Pesticide poisoning; Cholinesterase agents; Oxime; Pralidoxime chloride; Pralidoxime iodide; Antidote; Dosage

Variation in the susceptibility of okra (Abelmoschus esculentus L. Moench) genotypes to okra mosaic virus and Podagrica species under field conditions

A total of 21 okra (Abelmoschus escuentus L. Moench) genotypes were screened for their reactions against okra mosaic disease (OMD) and flea beetles (Podagrica species) infestations in field trials which were conducted from May to October, 2015 (wet season) and November 2015 to March 2016 (dry season), in order to identify sources of resistance and or tolerance. The trials were laid out in a randomised complete block design (RCBD) with four replications. Field resistance in the genotypes was assessed at 2, 6 and 10 weeks after planting using a 0 to 5 visual scale based on disease symptoms (where 1 denotes no symptom and 5, very severe symptom). Enzyme linked immunosorbent assay (ELISA) was performed to detect the presence of Okra mosaic virus (OkMV) in the okra genotypes. Populations of the flea beetle (Podagrica spp.), the vector of OkMV, and the associated leaf and fruit damage were also assessed. All the okra genotypes exhibited a varying range of disease symptoms and the flea beetle infestations, and lacked immunity. Genotypes GH2052, GH2063, GH2026, GH3760, GH5302, GH5332, GH5793, GH6105 and UCCC6 exhibited mild symptoms of OMD, and were less susceptible to flea beetle infestation and associated leaf damage during both seasons. Using ELISA, OkMV was detected in all the 21 genotypes. The mean number of fruits per plant and the mean fruit yield (t ha-1) differed significantly (P<0.05) among the okra genotypes. Genotype GH5332 had the highest fruit yield of 11.88 t ha-1 followed by genotype GH6105 (9.34 t ha-1). Percentage fruit damage due to the flea beetle infestation differed significantly among the okra genotypes, ranging between 43.7 and 91.2% and from 47 to 84% in both trials respectively. Key words: Enzyme linked immunosorbent assay (ELISA), insecticides, Abelmoschus esculentus, okra mosaic disease, Podagrica species.

Advances of Studies on Microbial Degradation of Pyrethroid Insecticides

Advances of Studies on Microbial Degradation of Pyrethroid Insecticides

Combate químico de THRIPS TABACI (thysanoptera: thripidae) en el cultivo de cebolla, en Morelos, México

El cultivo de cebolla presenta altas poblaciones del trips (Thrips tabaci Lindeman), lo que ocasiona marchitez prematura, retarda el desarrollo de la hoja y distorsiona los brotes vegetativos. Los agricultores han usado diferentes plaguicidas para el manejo del trips, sin tener en cuenta la rotación de grupos químicos y dosis adecuadas, lo que ocasiona contaminación ambiental por el uso excesivo de agroquímicos. Por lo que el objetivo de este estudio, fue evaluar seis grupos de plaguicidas para el manejo de trips, los cuales fueron rotados durante el ciclo del cultivo, así como también se identificó la especie de trips presente en el cultivo de la cebolla. El estudio inició en octubre de 2013, en un cultivo de cebolla, ubicada en Ayala, Morelos. Cada tratamiento consistió en la aplicación de los siguientes insecticidas: T1: Testigo (sin producto); T2: Movento, Velcefate, Muralla, Tracer; T3: Regent, Muralla, Movento, Seizer+ Agromectin; T4: Tracer, Movento, Curacron, Muralla; T5: Actigard, Tracer, Colt, Agromectin; T6: Evisect-s, Curacron, Tracer, Calypso. Para determinar el control de los insecticidas, se contabilizó el número de ninfas y adultos de trips. Con los datos del número de ninfas y adultos de trips en los diferentes tratamientos, se realizó un análisis de varianza y separación de medias con la prueba Tukey (? 0.05). Para determinar las especies de trips presentes, se tomó una muestra en las hojas de las plantas de cebolla. Los insecticidas que lograron un control de las ninfas de trips en el cultivo de cebolla, fueron el Tracer, Acefate, Curacron y la combinación de Seizer+ Agromectin. Los insecticidas Tracer y Muralla, fueron los que mantuvieron las poblaciones más bajas de adultos de trips en el cultivo de cebolla. La especie de trips predominante en el cultivo de cebolla durante el estudio fue Thrips tabaci L.

Eficácia de milho transgênico tratado com inseticida no controle da lagarta-do-cartucho no milho safrinha no estado de São Paulo, Brasil

RESUMO Diversas tecnologias de milho geneticamente modificado (Bt) foram liberadas comercialmente desde 2007 visando principalmente o controle da lagarta-do-cartucho, Spodoptera frugiperda (Lepidoptera: Noctuidae). O objetivo deste trabalho foi avaliar a eficiência de híbridos transgênicos (Bt) e convencionais (não Bt) no controle lagarta-do-cartucho, submetidas ou não a inseticidas. Para isso, foram conduzidos ensaios em três localidades do estado de São Paulo nas safrinhas de 2009, 2010 e 2011, com delineamento experimental de blocos casualizados, em esquema fatorial 5x4, 5x4 e 8x4, respectivamente. O primeiro fator correspondeu ao número de híbridos comerciais de diferentes empresas. O segundo fator foi constituído pela utilização de diferentes manejos de controle do inseto. Para a avaliação dos danos ocasionados pela lagarta-do-cartucho, foram realizadas amostragens ao acaso de 20 plantas por parcela, aplicando-se uma escala de notas visuais, atribuindo notas que variam de 0 (sem dano) a 9 (cartucho totalmente destruído) e obtido a produtividade de grãos. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade, para cada parâmetro avaliado em cada localidade. Os híbridos transgênicos proporcionaram redução nas notas de danos atribuídas a lagarta-do-cartucho e as proteínas Cry 1F, Cry 1A105 e VIP3Aa20 foram as mais eficientes na redução do dano foliar. A pulverização mostrou-se uma estratégia eficiente em reduzir os danos foliar provocados pela praga. A combinação da pulverização com híbrido transgênico, de modo geral, mostrou ser uma boa estratégia para redução de dano foliar, especialmente quando foi utilizada a proteína Cry 1Ab, comprovadamente de menor eficiência para redução dos danos causados pela praga.

Physico-chemical Properties of the Biosurfactant Obtained from Fruit Extract of Genipa Americana L. and Tamarindus Indica L. and Its Application in Oil Removal

In the last years, the industrial application of natural surfactants of origin of fruits, vegetables, nuts and grains has increased due to its potential physicochemical properties (foaming, emulsification, solubilization, sweetener, bitterness) and biological activities (hemolytic, antimicrobial, insecticide). These natural alternatives are considered economically and environmentally viable and explored to various purposes including the bioremediation of soils contaminated by oils. The aims of the present study were to evaluate the surfactants properties of the ethyl acetate extracts obtained from the fruits Genipa americana L. (Genipap) and Tamarindus indica L. (Tamarinds) and their applications in oil removal. The physico-chemical analyzes performed were surface tension, emulsification activity using different hydrocarbons and vegetable oils, surface tension stability in different temperatures, pH and addition of salt, and test of dispersion. To evaluate the capacity of this extracts (biosurfactants) on oil removal in engine parts, small-scale tests were conducted using glass blade. The results showed that this ethyl acetate extracts obtained from fruits extract exhibited surfactant properties due to the reduction of the surface tension of water from 72mN/m to 31.57mN/m and 34.71mN/m with the critical micelle concentration of 0.95g/L e 1.9g/L, with the increase values of the emulsification activity ranging from 32% and 100%. The results also showed a considerable stability of these biosurfactants derived from fruit extract submitted to different temperature, pH and salt concentrations as well as their compatibility with chemical surfactants. The biosurfactants obtained from fruit extract of G. americana and T. indica can be considered new perspectives on oil removal from engine parts with future potential to be marketed and replace the application of chemical surfactants.

Effect of agrochemicals on macroinvertebrate assemblages in Pampasic streams, Buenos Aires, Argentina

Fil: Solis, Marina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Limnologia Dr. Raul A. Ringuelet. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnologia; Argentina

The Dynamics of Agricultural Land Management System in Bangladesh: The Challenges for Sustainable Development

Bangladesh is a densely populated country of 142.3 millions people where 964 person live per sq. km. It is located in the north-eastern part of South Asia. Although it is predominantly an agriculture dependent country, it has the lowest land man ratio in the world and it accounts fro 0.06 hactres per person. Every year around 18-20 lacs people are born to soar the existing overpopulation. In addition, 47.3% of the total labour forces of the the country are employed in agriculture and it provides 21% of Gross Domestic Product (GDP) of the country. To meet the multiple demands of the ever increasing population the scarce agricultureal lands of this country are being misused for non-agricultural purposes. Besides, excessive use of chemical fertilizers, insecticides and intensive cultivation of lands without necessary conservation practices gradually deteriorates the productive capacity of the agricultural lands. If the present trend of Agricultural land management system (ALMS) continues it may hamper the sustainable development of the country. This article examines the dynamics of ALMS in Bangladesh and investigates to indentify the key problems and challenges for promoting sustainable development in ALMS. Lastly, based on overall observations of the research, this article suggests several policy and administrative guidelines to promote sustainable development in agricultural land management in Bangladesh.

Biochemical Characterization of Insecticide Resistance and Exposure in Aedes Aegypti Population From Wonosobo, Central Java, Indonesia

Resistance to insecticides mainly occurs due to changes in insect metabolic enzyme. Increased metabolism is often caused by qualitative or quantitative changes of esterase and glutathione S-transferase. Susceptibility test and biochemical assay to detect organophosphate and synthetic pyrethroid resistance were conducted on Aedes aegypti from Wonosobo (new highland Dengue endemic area). The test were performed on F1 generation of Ae.aegypti field caught mosquitoes which aimed to determine the resistance mechanisms regarding two detoxifying enzymes i.e. esterase and glutathione S-transferase. Susceptibility test showed 23.4 and 46.7% mortalities after exposure to 0.8% malathion and 0.05% cypermethrin. The biochemical assay result suggested that esterase, monooxygenase and glutathione s-transferase activity tend to increase in Ae.aegypti in Wonosobo. Interview and questionaires conclude that synthethic pyrethroid was the only insecticide type used in vector control program by Wonosobo Health Office and was the most frequent insecticide type to be used in household by Wonosobo society to control Ae.aegypti population. Knowledge of localized resistance and underlying mechanisms helps in making rational decisions in selection of appropriate and effective insecticides in the event of a dengue outbreak.

Tank mixture of pesticides for Spodoptera frugiperda control in maize with triflumuron

Nowadays, few studies have been conducted to evaluate the effect of tank mixture of pesticides on pest chemical control in maize crops, however the farmers are often using these mixtures, without any technical support. The current study focused on assessing some pesticide mixtures to control Spodoptera frugiperda with triflumuron in a conventional corn hybrid. Moreover, this experiment aimed to assess likely plant physiological effects, as well as physical-chemical characteristics of these tank mixes. To this end, four treatments were carried out in a randomized block design with five replications, being repeated in two seasons. Treatments consisted of different pesticide mixtures, such as insecticide (INS) + adjuvant (ADJ); INS + ADJ + fungicide (FUN); INS + ADJ + FUN + foliar fertilizers (FF); control (Ctrl). The treatments underwent analyses of mixture physical-chemical characteristics, sampled caterpillar number and size, leaf gas exchange (IRGA), and amount of chlorophyll a and b. Spray liquid characteristics changed with used mixture. Fertilizer addition caused major changes in spray liquid properties as increasing pH and electrical conductivity. No effect was observed by mixing azoxystrobin, cyproconazole, zinc oxide and manganese sulfate to triflumuron concerning control effectiveness of Spodoptera frugiperda in the corn plants. Conversely, each pesticide mixture had a distinct effect on plant physiological variables.

Flubendiamide as New Generation Insecticide in Plant Toxicology: A Policy Paper

Flubendiamide as New Generation Insecticide in Plant Toxicology: A Policy Paper

Evaluation of Insecticides for Control of San Jose Scale in Alabama Peaches, 2015*

Evaluation of Insecticides for Control of San Jose Scale in Alabama Peaches, 2015*

Malaria Prevalence and Its Associated Risk Factors among Patients Attending Chichu and Wonago Health Centres, South Ethiopia.

There were about of 124 to 283 million cases of malaria with 367,000 to 755,000 deaths annually. This study aimed to assess the prevalence of malaria cases and associated risk factors among attendants at Chichu and Wonago health centers, South Ethiopia. In this health institution based cross sectional study, 324 subjects, attendants from outpatient department who came for any kind of medical services, were included during May to June 2016. A blood film examination format and structured questionnaire were used for data collection. Peripheral blood samples were collected and the presence of malaria cases was observed microscopically. The collected data were analyzed by SPSS version 20.0. Malaria cases were detected in 91 (28.1%) of the participants with higher infection rate amongst (56.04%). The predominant Plasmodium species detected was P. vivax (52.75%) followed by P. falciparum (35.16%) and mixed malaria infection by both of the species (12.09%). Housing construction and not using of insecticide treated bed nets for the last 6 months were significantly associated with the risk of getting malaria. Individuals who had stagnant water in their compound were more likely to get malaria than those who did not (OR=1.87, 95% CI: 1.20, 2.76). Houses that had been sprayed with insecticide in the past 6 months were protected against malaria infection (OR=0.33, 95% CI: 0.11, 0.92). Moreover, bed net utilization was associated with a significantly lower risk of infection (OR=0.19, 95% CI: 0.09, 0.37). Type of housing construction, not using bed net, insecticide spraying and residing near stagnant water were associated risk factors with malaria positivity in the study area.

Efecto de los insecticidas en el equilibrio natural de poblaciones de Rothschildia aroma Schaus (Lepidoptera: Saturniidae) en El Salvador

A three year period of observations, collecting, and recording data on cocoons of Rothschildia aroma Schaus showed that parasitism is still high enough (63.1%) in areas free of insecticide applications to account for a good natural balance, with moth survival being only 11.4%. In contrast, in areas where intense and continuous applications have been going on for the last ten years, the percentages have been practically reversed, parasitism reaching only 18.1% and moth survival 68.4%. Emphasis is placed on this previously cryptic case of natural biological control, and others that may have been or are being disrupted in El Salvador and other countries oE Central America.

The WHO’s Need to Address Insecticide Resistance in Malaria Vectors

ABSTRACTSince 2000, incidence and mortality rates attributable to malaria have declined significantly. However, this decline may be short-lived due to the emergence of insecticide-resistant malaria vectors caused by the overuse of indoor residual spraying (IRS) and insecticide treated nets (ITNs). This policy paper will discuss the emergence, causes, and implications of vector resistance and will propose solu­tions to prevent a future public health crisis.RÉSUMÉDepuis 2000, l’incidence et les taux de mortalité attribuables au paludisme ont diminué significativement. Toutefois, ce déclin risque d’être de courte durée en raison de l’émergence de vecteurs du paludisme résistants aux insecticides, causée par la surutilisation de la pulvérisation intradomiciliaire (PID) et de moustiquaires imprégnées d’insecticides (MII). Cet article de politique discutera de l’émergence, des causes et des implications de la résistance des vecteurs, et proposera des solutions dans le but de prévenir une éventuelle crise sanitaire.