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Sitotroga cerealella is one of the major pests of cereals in the field and storage conditions throughout the world. The main objective was to study the life tables of S. cerealella on wheat, maize and barley and its implications on percent parasitism of Trichogramma chilonis. S. cerealella is reared under lab conditions as its eggs are utilized for rearing T. chilonis. Fresh eggs of S. cerealella were collected and after hatching the neonate larvae of S. cerealella were transferred onto each host plant species for obtaining first (F1) generation (G). Seventy eggs were used for each host and each egg was used as a replicate. Daily observations were made for recording the life-table parameters of the S. cerealella. The data showed that the developmental time of S. cerealella eggs and pupae was maximum (5.68 and 7.75 days) when reared on wheat, while the maximum larval duration (19.77 days) of S. cerealella was recorded on barley. The maximum fecundity (290.30 ± 22.47 eggs/female) was recorded on maize, while minimum fecundity per female was recorded on barley (159.30 eggs/ female). The S. cerealella reared on maize had significantly higher values of finite rate of increase (λ), intrinsic rate of increase (r), and net reproductive rate (Ro) (0.14 ± 0.04 day- 1, 1.16 ± 0.05 day- 1, and 136.85 ± 20.25 eggs/ female) respectively. The mean generation time (T) (35.18 ± 0.61 days) was higher on wheat. Likewise, the gross reproductive rate (GRR) and the age-stage specific reproductive values (vxj) of newly oviposited eggs of S. cerealella were recorded higher (136.85 ± 20.25; 1.160 offspring) on maize. The data regarding the efficacy of T. chilonis for different parameters were recorded higher on maize i.e., percent parasitism (89.00 ± 2.30%), percent adult emergence (81.60 ± 1.20%), adult longevity (3.80 ± 0.10 days) and total adult longevity (9.90 ± 0.20 days) as compared to wheat and barley. Our findings revealed that S. cerealella can be best reared on maize under laboratory conditions as it prefers this host as compared to wheat and barley. Therefore, assigning the most susceptible and favorite host (maize) would help us to improve T. chilonis mass production under laboratory conditions.
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Himenópteros , Mariposas , Vespas , Animais , Feminino , Humanos , Recém-Nascido , Grão Comestível , Tábuas de Vida , Larva , Triticum , Zea maysRESUMO
BACKGROUND: Subclinical seizures(SCSs) are overlooked in clinical practice. This study aims to investigate clinical, electrophysiological features of SCSs detected during video-electroencephalography(EEG) monitorization(VEM), concordance of the epilepsy type and SCSs, and predictors of the concordance. METHODS: The data of drug-resistant epilepsy patients who had undergone video-EEG between 2010 and 2020 were investigated. Ictal activities showing temporospatial evolution lasted ≥ 10 s, without any behavioural changes were considered SCSs. Findings were re-evaluated for ictal localization, lateralization, ictal discharge type, vigilance status, and duration of SCSs to the accompaniment of clinical findings. Additionally, the concordance of epilepsy type and SCSs were analyzed. RESULTS: Fifty-five SCSs were obtained in 24 of 804 patients (2,9 %) who were followed in the VEM unit; the epilepsy type of the patients was temporal in 26 and extratemporal lobe epilepsy in 29 SCSs. Among 55 SCSs recordings, 30 originated from the temporal lobe and 24 from the extratemporal lobe, and seizure localization could not be determined in one. The patients were younger, age at seizure onset was earlier, habitual seizures were more frequent, multiple anti-seizure drug use was higher, seizures more frequently occurred during sleep, cranial MR tended to be abnormal, patients were more likely to have a history of perinatal injury/head trauma, and the concordance of discharge patterns was lower in extratemporal SCSs.The concordance of epilepsy type with localization and lateralization of SCSs was not statistically significant. CONCLUSIONS: SCSs originating from the temporal and extratemporal lobes might show similar characteristics with the epilepsy type, and SCSs might have clinical importance apart from epilepsy surgery.
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Epilepsias Parciais , Epilepsia do Lobo Temporal , Epilepsia , Humanos , Couro Cabeludo , Epilepsias Parciais/diagnóstico , Prognóstico , Eletroencefalografia , DemografiaRESUMO
The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most notorious insect pest of potato globally. Injudicious use of insecticides for management of this pest has resulted in resistance to all major groups of insecticides along with many human, animal health, and environmental concerns. Additionally, the input cost of insecticide development/discovery is markedly increasing because each year thousands of chemicals are produced and tested for their insecticidal properties, requiring billions of dollars. For the management of resistance in insect pests, synergists can play a pivotal role by reducing the application dose of most insecticides. These eco-friendly synergists can be classified into two types: plant-based synergists and RNAi-based synergists. The use of plant-based and RNAi-based synergists in resistance management of insect pests can give promising results with lesser environmental side effects. This review summarizes the resistance status of CPB and discusses the potential advantage of plant-based and RNAi-based synergists for CPB resistance management. It will motivate researchers to further investigate the techniques of using plant- and RNAi-based synergists in combination with insecticides.
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PURPOSE: Ictal hypoxemia is accepted as one of the mechanisms underlying sudden unexpected death in epilepsy (SUDEP). Although ictal hypoxemia is more common in generalized seizures, it also occurs in focal seizures with or without generalization. In this study, we aimed to show the relationship between clinical and electroencephalographic findings of seizures in patients with temporal lobe epilepsy (TLE) with periictal oxygen saturation. METHODS: The data of 55 adult patients who were hospitalized in the Video EEG Monitoring Unit (VEMU) and operated on for drug-resistant TLE between January 2017 and December 2020 were examined. Forty-five seizures from 21 patients with ictal peripheral arterial saturation information and that were seizure-free for at least a year during the follow-up were included in the study. RESULTS: The median patient age was 28 (IQR 25-39.5) years (women: 9, men: 12). Age at epilepsy onset was negatively correlated with saturation at seizure onset. Moreover, the age at VEMU admission was also negatively correlated with saturation at seizure onset and the lowest levels of saturation. The saturation at the end of the seizures and the lowest saturation measured in the periictal period with generalization of EEG were significantly lower than those without generalization. The onset of ictal EEG with the rhythmic theta pattern was significantly associated with the lowest level of saturation (<90%), postictal generalized electroencephalographic suppression (PGES), and the presence of generalization. CONCLUSION: According to the study, rhythmic ictal theta activity, older age, nocturnal seizure, and generalization in ictal EEG might increase the potential risk of SUDEP. Further studies including a greater number of subjects and different epilepsy syndromes may provide more comprehensive information about potential biomarkers for SUDEP.
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Epilepsia do Lobo Temporal , Morte Súbita Inesperada na Epilepsia , Adulto , Morte Súbita , Eletroencefalografia , Feminino , Humanos , Hipóxia , Masculino , Saturação de Oxigênio , ConvulsõesRESUMO
INTRODUCTION: One of the unknown mechanisms in epilepsy pathogenesis is the involvement of the hypothalamic neuropeptide orexin. Although the relationship between orexin and sleep has been revealed, its effect in epilepsy has not been fully clarified. In this study, we aimed to show the relationship between orexin A and the seizures that occur during sleep and wakefulness. MATERIAL AND METHODS: This study included 40 patients with drug-resistant focal epilepsy and 37 healthy controls. Night basal orexin (NBO) and morning basal orexin (MBO) levels were measured using enzyme-linked immunosorbent assay in patients and controls. Serum samples were collected from patients after epileptic seizures during sleep and wakefulness. RESULTS: In both patients and controls, MBO levels (median: 1039 pg/mL, interquartile ranges [IQR] (899-1078)) were higher than NBO levels (median 989 pq/mL, IQR (893-1078) (p = 0.02). Basal orexin levels were lower in patients than in controls (p < 0.001). However, while the duration of seizures was shortened in awake seizures, the level of orexin increased (p = 0.007). Additionally, orexin levels after nocturnal seizure were higher in patients who had an ictal electroencephalography onset in the left hemisphere or a lesion in the left temporal lobe (p = 0.02; p = 0.01, respectively). There was no relationship between postictal somnolence and orexin levels. Although there was no significant difference, the level of post-seizure orexin increased compared to the basal values, especially in seizures during sleep. DISCUSSION: The increase in serum orexin levels, especially after seizures, suggests that orexin may be associated with the epileptogenic effect. In further studies, determination of orexin from cerebrospinal fluid (CSF) and correlation of CSF and serum orexin levels may provide more useful information regarding the relationship between orexin and epilepsy.
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Epilepsia , Eletroencefalografia , Epilepsia/complicações , Humanos , Orexinas , Convulsões/complicações , VigíliaRESUMO
Objectives: The aim of this pilot study was to evaluate dynamic thiol-disulfide homeostasis as a novel oxidative stress parameter in multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) to better understand the role of thiol homeostasis in neuroimmunological diseases. Methods: A total of 85 participants were included in this study, consisting of 18 healthy controls, 52 patients diagnosed with MS, seven with NMOSD, and eight with MOGAD. We measured total thiol (-SH+-S-S-) and native thiol (-SH) levels in the serum of all the participants, and in a subset of patients (n = 11), these parameters were investigated in paired cerebrospinal fluid (CSF) and serum samples. Dynamic disulfide concentrations were calculated separately. Finally, we determined if there was any relationship between clinical features and dynamic thiol homeostasis. Results: There was a statistically significant difference between serum and CSF levels of biomarkers of thiol homeostasis. Serum total thiol (317.88 ± 66.04) and native thiol (211.61 ± 44.15) levels were significantly lower in relapsed patients compared to those in remission (368.84 ± 150.36 vs. 222.52 ± 70.59, respectively). Conclusions: Oxidative stress plays a crucial role in the physiopathology of neuroimmunological diseases. Thiol homeostasis may be useful for monitoring disease activity.
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Temporal encephaloceles (TEs) are one of the cause of refractory temporal lobe epilepsy (TLE). We reviewed the neuroimaging and video-electroencephalography (EEG) records of epilepsy patients who underwent temporal lobectomy in our center to investigate frequency of TEs. We retrospectively reevaluated 294 patients who underwent epilepsy surgery in our tertiary epilepsy centre between January 2010 and March 2019 and included 159 patients (78 females, 49 %; 81 males) who had temporal lobectomy. Preoperatively, TEs were reported in 3 of 159 patients (1 female, 2 males). After reevaluation 4 more patients with TEs (1 female, 3 males) were added. The ratio of TE in patients who underwent temporal lobectomy increased from 1.8 % (n=3) to 4,4 % (n=7). The median ages were 18 (range 16-22) versus 10 years (range 5-17) at habitual seizure onset and the median of epilepsy duration was 5 (range 3-15) versus 175 (range 11-25) years between patients with and without TE. Habitual seizure onset age was significantly higher (p =, 007) in the patients with encephalocele and epilepsy duration was shorter (p =, 003) than patients without encephalocele. The ictal EEG records of all patients TE rhythmic delta activity which is suggested neocortical temporal lobe onset seizures. 4 of 7 patients' PET imaging showed temporal lobe hypometabolism compatible with ipsilateral to the TEs. The three patients underwent anterior temporal lobectomy without amygdalohippocampectomy and others had anterior temporal lobectomy with amygdalohippocampectomy. We suggested that there might be some clues for temporal encephalocele, an easily overlooked cause in patients with nonlesional temporal lobe epilepsy.TLE patients with TE had relatively late onset of epilepsy and rhythmic delta activity on ictal EEG. Also, temporal hypometabolism on PET may be a useful key to suspicion of TE.
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Encefalocele , Epilepsia do Lobo Temporal , Adolescente , Adulto , Lobectomia Temporal Anterior , Eletroencefalografia/métodos , Encefalocele/complicações , Encefalocele/diagnóstico por imagem , Encefalocele/cirurgia , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/cirurgia , Resultado do Tratamento , Adulto JovemRESUMO
Colorado potato beetle, Leptinotarsa decemlineata Say (coleoptera: chrysomelidae), is the important pest of potato all over the world. This insect pest is resistant to more than 50 active compounds belonging to various chemical groups. Potential of RNA interference (RNAi) was explored to knock down transcript levels of imidacloprid resistant genes in Colorado potato beetle (CPB) under laboratory conditions. Three important genes belonging to cuticular protein (CP), cytochrome P450 monoxygenases (P450) and glutathione synthetase (GSS) families encoding imidacloprid resistance were targeted. Feeding bio-assays were conducted on various stages of imidacloprid resistant CPB lab population by applying HT115 expressing dsRNA on potato leaflets. Survival rate of insects exposed to CP-dsRNA decreased to 4.23%, 15.32% and 47.35% in 2nd, 3rd and 4th instar larvae respectively. Larval weight and pre-adult duration were also affected due to dsRNAs feeding. Synergism of RNAi with imidacloprid conducted on the 2nd instar larvae, exhibited 100% mortality of larvae when subjected to reduced doses of GSS and CP dsRNAs along with imidacloprid. Utilization of three different dsRNAs against imidacloprid resistant CPB population reveal that dsRNAs targeting CP, P450 and GSS enzymes could be useful tool in management of imidacloprid resistant CPB populations.
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Besouros/genética , Resistência a Medicamentos/genética , Genes de Insetos , Inseticidas/farmacologia , Larva/metabolismo , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/genética , Regulação para Baixo , Resistência a Medicamentos/efeitos dos fármacos , Glutationa Sintase/genética , Larva/efeitos dos fármacos , Larva/genética , Interferência de RNA/efeitos dos fármacos , Solanum tuberosum/crescimento & desenvolvimentoRESUMO
During the next decade it will be necessary to develop novel combinations of management strategies to sustainably increase crop production and soil resilience. Improving agricultural productivity, while conserving and enhancing biotic and abiotic resources, is an essential requirement to increase global food production on a sustainable basis. The role of farmers in increasing agricultural productivity growth sustainably will be crucial. Farmers are at the center of any process of change involving natural resources and for this reason they need to be encouraged and guided, through appropriate incentives and governance practices, to conserve natural ecosystems and their biodiversity, and minimize the negative impact agriculture can have on the environment. Farmers and stakeholders need to revise traditional approaches not as productive as the modern approaches but more friendly with natural and environmental ecosystems values as well as emerging novel tools and approaches addressing precise farming, organic amendments, lowered water consumption, integrated pest control and beneficial plant-microbe interactions. While practical solutions are developing, science based recommendations for crop rotations, breeding and harvest/postharvest strategies leading to environmentally sound and pollinator friendly production and better life in rural areas have to be provided.
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Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Biodiversidade , Produção Agrícola , Produtos Agrícolas , Ecossistema , Europa (Continente) , Melhoramento VegetalRESUMO
We compared rearing Harmonia dimidiata (F.) (Coleoptera: Coccinellidae) on four combinations of Aphis gossypii Glover (Hemiptera: Aphididae), and eggs of Bactrocera dorsalis Hendel (Diptera: Tephritidae), using the age-stage, two-sex life table. The four combinations were: both larvae and adults were reared on aphids; larvae were reared on aphids and adults were reared on fresh fruit fly eggs; larvae were reared on lyophilized fruit fly eggs and adults were reared on aphids; and larvae were reared on lyophilized eggs and adults were reared on fresh eggs. The highest intrinsic rate of increase (r = 0.1125 d-1) and net reproductive rate (R0 = 260.7 offspring) were observed when both larval and adult stages of H. dimidiata were reared on A. gossypii. When B. dorsalis eggs were used as rearing media for larvae, adults, or both, the values of r and R0 were significantly decreased. The lowest values (r = 0.0615 d-1 and R0 = 38.6 offspring) were observed when both larvae and adults were reared entirely on B. dorsalis eggs. Despite the lower r and R0 values, our results showed that B. dorsalis eggs could be considered as an adequate, less expensive alternative diet for rearing H. dimidiata because of the time and labor savings resulting from the ease of preparation and the ability to store the eggs for timely usage. The mass-rearing analysis showed that the most economical rearing system was to rear larvae on A. gossypii and adults on B. dorsalis eggs.
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Besouros/crescimento & desenvolvimento , Criação de Animais Domésticos , Animais , Afídeos , Feminino , Fertilidade , Tábuas de Vida , Masculino , Óvulo , Controle Biológico de Vetores , Crescimento Demográfico , Reprodução , TephritidaeRESUMO
Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a serious pest that is capable of bisexual and arrhenotokous reproduction. In arrhenotokous reproduction, virgin females initially produce male offspring; later, when their sons are sexually mature, the mothers begin bisexual reproduction by carrying out oedipal mating with their sons. Because a virgin female produces many male offspring before oedipal mating occurs, multiple oedipal mating is common. In this study, we investigated the effect of multiple oedipal mating on the population growth of F. occidentalis by using the age-stage, two-sex life table theory. In the arrhenotokous cohorts, all unfertilized eggs developed into males. In the bisexual cohorts, the offspring sex ratio was significantly female biased with the mean number of female offspring and male offspring being 72.68 and 29.00, respectively. These were the same as the net reproductive rate of female offspring and male offspring. In arrhenotokous cohorts, the number of males available for oedipal mating significantly affected the production of female offspring. The number of female offspring increased as the number of sons available for oedipal mating increased. Correctly characterizing this unique type of reproduction will provide important information for predicting the timing of future outbreaks of F. occidentalis, as well as aiding in formulating successful management strategies against the species.
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Partenogênese , Razão de Masculinidade , Tisanópteros/fisiologia , Animais , Crescimento DemográficoRESUMO
Temperature has significant effects on the development, survival, and reproduction of ectothermic organisms. In this study, we examined the effect of temperature on the demographic characteristics of two predatory mite species, Neosciulus womersleyi (Schicha) and N. longispinosus (Evans), reared on Tetranychus urticae Koch. The developmental and reproductive traits of both species were examined at 10 constant temperatures between 15 °C and 37.5 °C. The preadult development time of N. womersleyi and N. longispinosus decreased with increasing temperature until 32.5 °C and 35 °C, respectively. The lower developmental threshold (T0) and thermal constant (K) estimated by using a linear model were 11.61 °C and 69.36 DD for N. womersleyi and 11.92 °C and 61.5 DD for N. longispinosus, respectively. Total preoviposition period and total longevity of females and males of N. womersleyi and N. longispinosus decreased with increasing temperature. The mean generation time (T) first decreased with temperature until 32.5 and 35 °C for N. womersleyi and N. longispinosus, respectively, and then increased at higher temperatures. The R0 and r values first increased with temperature until 32.5 and 30 °C for N. womersleyi and N. longispinosus, respectively, and then decreased at higher temperatures. The R0 and r values for N. longispinosus at 37.5 °C were 0.3 offspring and -0.143 d-1, respectively. These results show that N. longispinosus is less fit than N. womersleyi at 37.5 °C.
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Tábuas de Vida , Longevidade , Ácaros/fisiologia , Animais , Feminino , Cadeia Alimentar , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ácaros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Comportamento Predatório , Reprodução , Taiwan , Temperatura , TetranychidaeRESUMO
Luciaphorus perniciosus Rack is one of the most serious pests of several cultivated mushroom species including Ganoderma lucidum (Fr.), Flammulina velutipes Karst., Auricularia polytricha (Mont.) Saac., Lentinus polychrous Lev., and Lentinus squarrosulus (Mont.) Singer in Thailand. Adult female Lu. perniciosus produce offspring inside their physogastric hysterosomas, with all embryos developing through to the adult stage while remaining in the abdomen. Once the abdomen ruptures, the female parent dies and the offspring consisting of mostly fertilized female adults along with a few male adults continue to emerge from the cadaver of the mother for a period of several days. This peculiar type of reproduction after the death of the mother is a special case for life table analysis and has not been discussed previously in demographic analyses. In this study, the life table data of this mite fed on Le. squarrosulus were collected at 25, 30, and 35 °C and analyzed by using the age-stage, two-sex life table. The standard errors of population parameters were estimated by using the bootstrap technique (200,000 bootstraps). At 25, 30, and 35 °C, females started reproduction at ages 9, 5, and 3 d, respectively; the net reproductive rates (R0) were 192.27, 253.81, and 234.11 offspring. Due to their rapid development and high fecundity, the r values were as high as 0.4189, 0.8653, and 1.0892 d-1 at 25, 30, and 35 °C, respectively. Computer projection indicated that the mushroom mites Lu. perniciosus is capable of a threefold daily increase at 35 °C.
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Cadeia Alimentar , Ácaros/fisiologia , Polyporaceae/crescimento & desenvolvimento , Animais , Feminino , Herbivoria , Tábuas de Vida , Masculino , Crescimento Demográfico , Reprodução , Temperatura , TailândiaRESUMO
The life table data for the oriental fruit fly, Bactrocera dorsalis (Hendel), at different adult sex ratios (1â: 1â, 1â: 50â, 50â: 1â free-choice mating, and 50â: 1â no-choice mating) were collected to determine the effects of sex-ratio manipulation on current pest control procedures. At 1â: 1â, females mated, on average, 2.3 times during their lifetime with a mean fecundity (F) of 1,122 eggs. The net reproductive rate (R0), intrinsic rate of increase (r), finite rate (λ), and mean generation time (T) were 561.0 offspring, 0.1693 d- 1, 1.1844 d- 1, and 37.4 d, respectively. At 50â: 1â free-choice mating, males mated 46.7 times during their lifetime, while at 50â: 1â no-choice mating, males mated on average 50 times during their lifetime, and all females mating only once in both treatments. The values for F, r, and λ were significantly lower for both 50â: 1â treatments than those in the 1â: 1â group; the R0 values, however, were either equal to or even higher than those in the 1â: 1â treatment. In the male-biased sex ratio (1â: 50â), fecundity was the highest (1,610 eggs) and female average life span the longest (166 d), while the R0 was the lowest (31.6 offspring) among all treatments. Population projections showed that even at a sex ratio of 50â: 1â, B. dorsalis could still produce a large number of offspring. These findings demonstrate that management strategies for controlling B. dorsalis could be properly evaluated by using demographic methods. Because female annihilation appears to be a more effective control strategy, it should be considered as a viable alternative.
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Controle Biológico de Vetores/métodos , Tephritidae , Animais , Feminino , Fertilidade , Tábuas de Vida , Masculino , Crescimento Demográfico , Reprodução , Razão de Masculinidade , Tephritidae/fisiologiaRESUMO
Insecticide resistance is one of the most important evolutionary phenomena for researchers. Overuse of chemicals has induced resistance in insect pests that ultimately has led to the collapse of disease control programs in many countries. The erroneous and inappropriate management of insect vectors has resulted in dissemination of many vector-borne diseases like dengue, malaria, diarrhea, leishmaniasis, and many others. In most cases, the emergence of new diseases and the revival of old ones can be related with ecological changes that have favored rapid growth of vector densities. Understanding molecular mechanisms in resistant strains can assist in the development of management programs to control the development and spread of resistant insect populations. The dominant, recessive, and co-dominant forms of genes encoding resistance can be investigated, and furthermore, resistance development can be addressed either by the release of susceptible strains or timely insecticide rotation. The present review discusses the resistance level in all important insect vectors of human diseases; the molecular basis of evolvement of resistance has also been discussed.
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Cidades , Insetos/efeitos dos fármacos , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Animais , Controle de Insetos/métodosRESUMO
Tanacetum chiliophyllum (Fisch. & Mey.) var. oligocephalum (D.C.) Sosn. collected in Turkey was subjected to phytochemical and biological evaluations in this study. Pure compounds were obtained from ethyl acetate extracts of the stems of the plant material. Structures of isolated compounds were determined using spectral methods. Seven known flavones, i.e., 5-hydroxy-3',4',6,7-tetramethoxyflavone, eupatilin (6-hydroxyluteolin-6,3',4'-trimethylether), cirsimaritin (scuttellarin-6,7-dimethylether), cirsilineol, 5-hydroxy-3',4',7-trimethoxy flavone, desmethoxy-centaureidin, and jaceosidin and one known triterpene, taraxasterol acetate, were identified from the ethyl acetate extracts. The first seven compounds, as well as the ethyl acetate and methanol extracts, were also investigated for their insecticidal, antimicrobial, and 1,1-diphenyl-2-picrylhydrazil radical (DPPH)-scavenging activities. The insecticidal contact toxicity of the extracts were evaluated on Sitophilus granarius. The ethyl acetate (81.8%) and methanol (88.4%) extracts of T. chiliophyllum var. oligocephalum showed high toxicity against this pest. Most promising antimicrobial activity was observed for ethyl acetate extracts of the stems against Bacillus cereus. This extract showed the same inhibition concentration (125 microL/mg) with the positive control chloramphenicol. The ethyl acetate (91.9%) and methanol (93%) extracts of the stems showed significant DPPH-scavenging activity compared with the positive controls alpha-tocopherol (94.5%) and butylated hydroxytoluene (92.9%) at 10 mg/mL concentration. Among the isolated compounds, the highest DPPH-scavenging activity was observed for jaceosidin at 1 mg/mL concentration (81.5%).
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Anti-Infecciosos/química , Sequestradores de Radicais Livres/química , Extratos Vegetais/análise , Tanacetum/química , Acetatos , Bacillus subtilis/efeitos dos fármacos , Compostos de Bifenilo/química , Hidroxitolueno Butilado/química , Cloranfenicol/química , Flavonas/análise , Flavonoides/análise , Flavonoides/química , Luteolina/análise , Metanol , Testes de Sensibilidade Microbiana , Picratos/química , Extratos Vegetais/química , Esteróis/química , Triterpenos/química , alfa-Tocoferol/químicaRESUMO
BACKGROUND: Dose-response relationships for antifeedant effects of H. lupulus extracts against larvae and adults of the Colorado potato beetle (CPB) were determined in laboratory conditions. The larval and adult beetles were fed on potato leaflets treated with H. lupulus extract ranging from 0.4 to 40 mg mL(-1) in a no-choice situation. Their feeding behavior was recorded, and larval growth and antifeedant indexes were calculated. RESULTS: H. lupulus treatments significantly affected larval growth rate, and at higher concentrations the larval weights were significantly reduced over the course of the assay. Adults of CPB were more sensitive to the extracts than the larvae, and, even at lower doses, adult beetles were arrested for longer periods than larvae. CONCLUSION: These results indicate that H. lupulus extracts may have potential for control of CPB, particularly in organic farms where conventional insecticides are not available.
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Besouros/efeitos dos fármacos , Besouros/fisiologia , Humulus/química , Larva/efeitos dos fármacos , Doenças das Plantas/parasitologia , Extratos Vegetais/farmacologia , Solanum tuberosum/parasitologia , Animais , Besouros/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Comportamento Alimentar/efeitos dos fármacos , Larva/fisiologiaRESUMO
BACKGROUND: The codling moth, Cydia pomonella (L.), is one of the principal pests of pome fruits in the world. The effects of novaluron, a benzoylurea chitin synthesis inhibitor insecticide registered for use on apples in the USA, on fecundity and egg viability in codling moth were studied under laboratory conditions. Three different exposure methods were investigated: ingestion, contact and topical spray. Additionally, the duration of novaluron sublethal effects was measured subsequent to the three modes of exposure. RESULTS: The fecundity of codling moth adults was not significantly affected by novaluron with any of the exposure methods. However, novaluron did cause significant reductions in the proportion of egg hatch with all three exposure methods. The duration of sublethal effects was 9 days or more for all modes of exposure, but with the topical spray these effects began to diminish after 6 days. CONCLUSION: Novaluron does not affect fecundity in codling moth, but has significant sublethal activity by reducing egg viability subsequent to adult exposure. The topical, contact and ingestion exposures all induce sublethal effects after exposure, and these persist to various degrees throughout codling moth oviposition. A more complete understanding of novaluron's lethal and sublethal activities will help IPM practitioners optimize its use for management of the codling moth.
Assuntos
Controle de Insetos/métodos , Mariposas/efeitos dos fármacos , Compostos de Fenilureia/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Feminino , Inseticidas/farmacologia , Masculino , Mariposas/crescimento & desenvolvimento , Mariposas/fisiologia , Oviposição/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Óvulo/fisiologiaRESUMO
In this study the authors employed the plant-insect-chemistry (PIC) triad to investigate two novel life stage targets against the plum curculio (PC), Conotrachelus nenuphar (Herbst), in apple integrated pest management (IPM). Laboratory treated apple bioassays were used to determine if the insect growth regulator (IGR) insecticides novaluron and tebufenozide have physiological effects on PC larvae following adult exposure. Curative activity bioassays were conducted for IGR, neonicotinoid, oxidiazine and organophosphate insecticides on PC larvae post-infestation, and fruit penetration profiles of insecticides were developed. The results revealed that novaluron exhibits activity on PC larvae via vertical transmission following exposure of mated females to treated substrate. Surface treatments of azinphos-methyl, thiacloprid and thiamethoxam to preinfested fruit resulted in significant reductions in larval emergence. For all compounds, 50% or more of the total recovered active ingredient was from apple skin, and for azinphos-methyl, indoxacarb and thiamethoxam it was greater than 80%. For azinphos-methyl, novaluron, methoxyfenozide and thiacloprid, however, active ingredient was recovered from every section of the apple, from skin to core. Implications for twenty-first century IPM are discussed.