pymetrozine and imidacloprid
pymetrozine has been researched along with imidacloprid* in 11 studies
Other Studies
11 other study(ies) available for pymetrozine and imidacloprid
Article | Year |
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Investigation of the dissipation behaviour and exposure of spitotetramat, flonicamid, imidacloprid and pymetrozine in open field strawberries in Egypt.
The dissipation behaviour and the consumer risk assessment of spitotetramat, flonicamid, imidacloprid and pymetrozine in open field strawberries were studied. Insecticides were applied at the authorised levels and the more critical good agricultural practice regimes (GAP). The initial concentrations varied from 0.069 to 1.75 mg kg Topics: Agriculture; Chromatography, Liquid; Dietary Exposure; Egypt; Food Analysis; Food Contamination; Fragaria; Insecticides; Kinetics; Neonicotinoids; Niacinamide; Nitro Compounds; Risk Assessment; Tandem Mass Spectrometry; Triazines | 2021 |
Differential metabolism of imidacloprid and dinotefuran by Bemisia tabaci CYP6CM1 variants.
Imidacloprid has been used to control one of most serious pests, Bemisia tabaci. However, B. tabaci has developed imidacloprid resistance mainly by over-expressing CYP6CM1. It was reported that imidacloprid-resistant B. tabaci showed no or low level of cross-resistance against dinotefuran. Here, we expressed CYP6CM1 variants using Sf9/baculovirus and/or Drosophila S2 cells and showed that CYP6CM1 variants metabolized imidacloprid but not dinotefuran. In addition, we demonstrated that imidacloprid and pymetrozine competed for a CYP6CM1 variant more efficiently than dinotefuran, using a luminescent substrate competition assay. These results suggest that lack of metabolic activity of CYP6CM1 variants against dinotefuran caused no or low level of cross-resistance. Topics: Animals; Guanidines; Hemiptera; Insect Proteins; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Triazines | 2019 |
No cross-resistance between imidacloprid and pymetrozine in the brown planthopper: status and mechanisms.
Cross-resistance between insecticides, especially from different groups, can be extremely unpredictable, and it has been a serious concern in pest control. Pymetrozine has been widely used to control Nilaparvata lugens with the suspension of imidacloprid for the resistance, and N. lugens has showed obvious pymetrozine resistance in recent years. To investigate the possible cross-resistance between imidacloprid and pymetrozine is very important to avoid the adverse effects on resistance development and pest control. Bioassays of two field populations in five consecutive years showed that imidacloprid resistance decreased greatly, while pymetrozine resistance increased significantly. The synergist piperonyl butoxide (PBO) could synergize both imidacloprid and pymetrozine in all field populations, which indicated the importance of P450s in the resistance to two insecticides. Imidacloprid resistance was reported to be associated with two P450s, CYP6AY1 and CYP6ER1, which could metabolize imidacloprid efficiently. However, the recombinant proteins of these two P450s did not show any enzymatic activity to metabolize pymetrozine. The pymetrozine susceptibility did not change when CYP6AY1 and CYP6ER1 mRNA levels were reduced by RNA interference (RNAi), although which could obviously decrease imidacloprid resistance. In vivo and in vitro studies provided evidences to demonstrate that there was no cross-resistance between imidacloprid and pymetrozine in N. lugens, which was different from the findings in Bemisia tabaci. Topics: Animals; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; Hemiptera; Imidazoles; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Real-Time Polymerase Chain Reaction; RNA, Bacterial; Triazines | 2016 |
[Resistance risk, cross-resistance and biochemical resistance mechanism of Laodelphax striatellus to buprofezin].
In order to investigate the resistance development law and biochemical resistance mechanism of Laodelphax striatellus to buprofezin, spraying rice seedlings was used to continuously screen resistant strains of L. striatellus and dipping rice seedlings was applied to determine the toxicity and cross-resistance of L. striatellus to insecticides. After 32-generation screening with buprofezin, L. striatellus developed 168.49 folds resistance and its reality heritability (h2) was 0.11. If the killing rate was 80%-90%, L. striatellus was expected to develop 10-fold resistance to buprofezin only after 5 to 6 generations breeding. Because the actual reality heritability of field populations was usually lower than that of the resistant strains, the production of field populations increasing with 10-fold resistance would need much longer time. The results of cross-resistance showed that resistant strain had high level cross-resistance with thiamethoxam and imidacloprid, low level cross-resistance with acetamiprid, and no cross-resistance with pymetrozine and chlorpyrifos. The activity of detoxification enzymes of different strains and the syergism of synergist were measured. The results showed that cytochrome P450 monooxygenase played a major role in the resistance of L. striatellus to buprofezin, the esterase played a minor role and the GSH-S-transferase had no effect. Therefore, L. striatellus would have high risk to develop resistance to buprofezin when used in the field and might be delayed by using pymetrozine and chlorpyrifos. Topics: Animals; Chlorpyrifos; Hemiptera; Imidazoles; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Oryza; Oxazines; Thiadiazines; Thiamethoxam; Thiazoles; Triazines | 2016 |
Variation in mortality among populations is higher for pymetrozine than for imidacloprid and spiromesifen in Trialeurodes vaporariorum in greenhouses in Finland.
Insecticide resistance in Trialeurodes vaporariorum W. is unknown in the species' northern distribution range where it inhabits mainly commercial greenhouses. Resistance development in whiteflies feeding on year-round crops in greenhouses is possible owing to the use of chemical treatments to back up biocontrol. The authors tested the response levels to spiromesifen, pymetrozine and imidacloprid in whiteflies collected from seven greenhouses within a 35 km radius in western Finland.. All except one (PR) population had LC50 values below the recommended concentrations for the tested compounds. However, some populations showed reduced susceptibility to pymetrozine in comparison with the reference susceptible population. Resistance ratios to pymetrozine were highly variable (resistance ratio 0.5-39.7), even among closely located greenhouses, and higher than those for imidacloprid (resistance ratio 1.05-10.5) and spiromesifen (resistance ratio 0.8-11.5). LC50 values and application frequencies of pymetrozine correlated positively among the sampled populations.. High variation in resistance levels to pymetrozine among populations within natural whitefly dispersal limits reflects variation in the usage of this compound among individual greenhouse crop producers. Thus, resistance management is recommended at the individual greenhouse crop producer level, even in a dense production cluster. © 2014 Society of Chemical Industry. Topics: Animals; Finland; Hemiptera; Imidazoles; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Pest Control; Spiro Compounds; Triazines | 2014 |
Toxicity of three insecticides to Lysiphlebus fabarum, a parasitoid of the black bean aphid, Aphis fabae.
The toxicity of three insecticides to Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae), a parasitoid of Aphis fabae Scopoli (Hemiptera: Aphididae), was investigated using IOBC/wprs protocols. Abamectin 1.8 EC, imidacloprid 350 SC, and pymetrozine 25 WP were tested under laboratory conditions at recommended field rates. Immature stages of the parasitoid were exposed to materials by briefly dipping mummified aphids into insecticide solutions/suspensions or water (controls). Abamectin, imidacloprid, and pymetrozine caused 44.8, 58.5, and 14.5% mortality of mummies, respectively. Insecticides were also applied to broad bean foliage until run-off using a hand sprayer and the contact toxicity of residues was investigated after 1, 5, 16 and 30 day periods of outdoor weathering by caging adult wasps on treated plants for 24 h. One day-old residues of abamectin, imidacloprid, and pymetrozine produced 52.5, 90.0 and 57.0% mortality, respectively, and 5 day-old residues produced 28.1, 77.0 and 18.6% mortality. Sixteen day-old residues produced 8.8, 22.4 and 13.6% mortality, whereas 30 day-old residues produced 0.0, 3.2 and 1.1% mortality, respectively. On the basis of these results, abamectin and pymetrozine were classified as short-lived compounds (Class A) and imidacloprid as a slightly persistent compound (Class B). Topics: Animals; Aphids; Imidazoles; Insecticides; Ivermectin; Neonicotinoids; Nitro Compounds; Triazines; Wasps | 2011 |
Cross-resistance relationships between neonicotinoids and pymetrozine in Bemisia tabaci (Hemiptera: Aleyrodidae).
Although cross-resistance between compounds in the same insecticide group is a frequently observed phenomenon, cross-resistance between groups that differ in structural and functional characteristics can be extremely unpredictable. In the case of controlling the whitefly, Bemisia tabaci Gennadius, neonicotinoids and the pyridine azomethine antifeedant pymetrozine represent independent lines of discovery that should be suited for alternation to avoid prolonged selection for the same resistance mechanism. Reports of an association between responses to neonicotinoids and pymetrozine were investigated by resistance profiling of seven B. tabaci strains and complementary reciprocal selection experiments.. All strains demonstrated a consistent correlation between responses to three neonicotinoid compounds: thiamethoxam, imidacloprid and acetamiprid. Responses to neonicotinoids for six field strains clearly correlated with responses to pymetrozine. Reciprocal selection experiments confirmed an unexpected case of intergroup cross-resistance. A seventh strain exhibited a so far unique phenotype of strong resistance to pymetrozine but full susceptibility to neonicotinoids. Selection experiments confirmed that in this strain the mechanism of pymetrozine resistance is specific and has no implications for neonicotinoids.. Cross-resistance between neonicotinoids and pymetrozine in B. tabaci probably reflects the overexpression of a cytochrome-P450-dependent monooxygenase capable of metabolising both types of compound in spite of their apparent structural dissimilarity. Given the predominance of this mechanism in B. tabaci, both can contribute to resistance management but should be placed within the same treatment 'window'. Topics: Animals; Gossypium; Hemiptera; Imidazoles; Insecticide Resistance; Insecticides; Lethal Dose 50; Neonicotinoids; Nitro Compounds; Oxazines; Plant Leaves; Pyridines; Thiamethoxam; Thiazoles; Triazines | 2010 |
Incidence and characterisation of resistance to neonicotinoid insecticides and pymetrozine in the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae).
Trialeurodes vaporariorum (Westwood), also known as the greenhouse whitefly, is a serious pest of protected vegetable and ornamental crops in most temperate regions of the world. Neonicotinoid insecticides are used widely to control this species, although resistance has been reported and may be becoming widespread.. Mortality rates of UK and European strains of T. vaporariorum to a range of neonicotinoids and pymetrozine, a compound with a different mode of action, were calculated, and significant resistance was found in some of those strains. A strong association was found between neonicotinoids and pymetrozine, and reciprocal selection experiments confirmed this finding. Expression of resistance to the neonicotinoid imidacloprid and pymetrozine was age specific, and resistance in nymphs did not compromise recommended application rates.. This study indicates strong parallels in the phenotypic characteristics of neonicotinoid resistance in T. vaporariorum and the tobacco whitefly Bemisia tabaci Gennadius, suggesting possible parallels in the underlying mechanisms. Topics: Animals; Hemiptera; Imidazoles; Insect Control; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Nymph; Plant Diseases; Triazines | 2010 |
Evaluation of the susceptibility of the pea aphid, Acyrthosiphon pisum, to a selection of novel biorational insecticides using an artificial diet.
An improved technique was developed to assay the toxicity of insecticides against aphids using an artificial diet. The susceptibility of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphidoidea) was determined for a selection of novel biorational insecticides, each representing a novel mode of action. Flonicamid, a novel systemic insecticide with selective activity as feeding blocker against sucking insects, showed high toxicity against first-instar A. pisum nymphs with an LC(50) of 20.4 microg/ml after 24 h, and of 0.24 microg/ml after 72 h. The toxicity was compared with another feeding blocker, pymetrozine, and the neonicotinoid, imidacloprid. In addition, four insect growth regulators were tested. The chitin synthesis inhibitor flufenoxuron, the juvenile hormone analogue pyriproxyfen, and the azadirachtin compound Neem Azal-T/S showed strong effects and reduced the aphid population by 50% after 3 days of treatment at a concentration of 7-9 microg/ml. The ecdysone agonist tested, halofenozide, was less potent. In conclusion, the improved aphid feeding apparatus can be useful as a miniature screening device for insecticides against different aphid pests. The present study demonstrated rapid and strong toxicity of flonicamid, and other biorational insecticides towards A. pisum. Topics: Animals; Aphids; Diet; Feeding Behavior; Imidazoles; Insect Control; Insecticides; Juvenile Hormones; Lethal Dose 50; Limonins; Neonicotinoids; Niacinamide; Nitro Compounds; Nymph; Phenylurea Compounds; Pyridines; Triazines | 2009 |
The persistence toxicity of three insecticides against adult of a thelytokous parasitoid, Lysiphlebus fabarum (Hymenoptera: Aphidiidae).
In order to investigate the effects of three insecticides on three day-old L. fabarum females (Hymenoptera: Aphidiidae), the parasitoid of Aphis fabae, an experiment was carried out using IOBC/wprs method. Persistence toxicity of insecticides has been evaluated in the semifield condition. The trials were laid out in randomized complete block design (RCBD) with 3 replicates and an untreated check. The insecticides abamectin 1.8 EC, imidacloprid 350 SC, and pymetrozine 25 WP were used at recommended field rates. The insecticides were applied on broad bean foliage using a hand sprayer, until run-off. Contact toxicity of semi field-aged residues of insecticides on adult parasitoids was evaluated using the cage-method. The mortality of adult parasitoid, after 24 h contact with 1-day old residues of abamectin, imidacloprid and pymetrozine were 53, 90 and 57%, respectively. After 5 days the effect of residues decreased so that the adult mortality diminished to 28, 77 and 18% for mentioned above insecticides. 16-day old residues lead to 9, 22 and 14%; and 30-day old residues lead to 0, 3 and 1% mortality for these insecticides, respectively. Based on this study, abamectin and pymetrozine with persistence less than 5 d are classified as short lived (Class A) and imidacloprid with persistence between 5 to 15d, classified as slightly persistent (Class B) compounds. Topics: Animals; Aphids; Environmental Pollutants; Female; Hymenoptera; Imidazoles; Insecticides; Ivermectin; Neonicotinoids; Nitro Compounds; Pesticide Residues; Time Factors; Triazines | 2009 |
Sublethal effects of imidacloprid and pymetrozine on the life table parameters of Aphis gossypii Glover (Homoptera: Aphididae).
In this study we report the sublethal effects of recommended concentrations of imidacloprid and pymetrozine on cotton aphid's reproduction. Fecundity life table parameters for AG were studied on cucumber under conditions of 25+/-1 degrees C, 70+/-5% RH and photoperiod of 16:8 (L:D). Leaf discs of cucumber immersed in the recommended concentrations of the above mentioned insecticides and controls and the new born female was released on the lower surface of leaf discs. Values of parameters such as adult longevity and daily fecundity rate were recorded. Standard error of population growth parameter was calculated using the Jacknife method. The results show that these two insecticides significantly reduce life table parameters compared with control. Topics: Animals; Aphids; Cucumis sativus; Dose-Response Relationship, Drug; Female; Fertility; Imidazoles; Insecticides; Longevity; Male; Neonicotinoids; Nitro Compounds; Triazines | 2005 |