Acute and Chronic Toxicity of Indoxacarb in Two Populations of Plutella xylostella (Lepidoptera: Plutellidae)

2020 ◽  
Author(s):  
Amanda A F Lemes ◽  
Thamiris P Sipriano-Nascimento ◽  
Natalia F Vieira ◽  
Camila P Cardoso ◽  
Alessandra M Vacari ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Control Treatment ◽  
Adult Survival ◽  
Mean Values ◽  
Treatment Groups ◽  
The Mean ◽  
Two Populations ◽  
Selection Of

Abstract The diamondback moth, Plutella xylostella (Linnaeus, 1758), is one of the main pests of brassicas, and various insecticides, such as indoxacarb, are used to control it. However, frequent insecticide applications favor the selection of resistant individuals. Thus, the residual and sublethal effects of indoxacarb in two populations of P. xylostella, one collected in the field (FP) and one from the laboratory (LP), were evaluated and compared. The objective of this research was to investigate the toxicity of indoxacarb at residual and sublethal levels in a field population of P. xylostella from Brazil and a population from the laboratory. Leaf-dip bioassays showed high toxicity, with LC50 values after 48 h of 3.7 and 6.9 mg/liter for the LP and FP, respectively. Sublethal effects were indicated by significant reduction in the survival of larvae, pupae, and offspring. There was an increase in foliar consumption and a decrease in adult survival in the LP, and a decrease in fecundity in the FP. For the LP and FP population, the mean values for R0, rm, and λ for the control treatment were significantly higher than for the treatment groups (CL15 and CL25). Exposure of larvae to sublethal indoxacarb concentrations significantly reduced larval and pupal survival. Larval and pupal survival decreased as the indoxacarb concentration increased. Fecundity was significantly lower for the FP at LC15 (96.2 eggs per female) and LC25 (69.2 eggs per female) concentrations compared with the other treatments.

Effects of rhizobacteria on the biology and behavior of Plutella xylostella (Lepidoptera: Plutellidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 195
Author(s):  
Robson Thomaz Thuler ◽  
Fernando Henrique Iost Filho ◽  
Hamilton César De Oliveira Charlo ◽  
Sergio Antônio De Bortoli
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Insect Behavior ◽  
Control Treatment ◽  
Pupal Weight ◽  
Larval Feeding ◽  
Direct Effects ◽  
Plant Feeding ◽  
Kluyvera Ascorbata ◽  
And Behavior

Plant induced resistance is a tool for integrated pest management, aimed at increasing plant defense against stress, which is compatible with other techniques. Rhizobacteria act in the plant through metabolic changes and may have direct effects on plant-feeding insects. The objective of this study was to determine the effects of cabbage plants inoculated with rhizobacteria on the biology and behavior of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). Cabbage seeds inoculated with 12 rhizobacteria strains were sowed in polystyrene trays and later transplanted into the greenhouse. The cabbage plants with sufficient size to support stress were then infested with diamondback moth caterpillars. Later, healthy leaves suffering injuries were collected and taken to the laboratory to feed P. xylostella second instar caterpillars that were evaluated for larval and pupal viability and duration, pupal weight, and sex ratio. The reduction of leaf area was then calculated as a measure of the amount of larval feeding. Non-preference for feeding and oviposition assays were also performed, by comparing the control treatment and plants inoculated with different rhizobacterial strains. Plants inoculated with the strains EN4 of Kluyvera ascorbata and HPF14 of Bacillus thuringiensis negatively affected the biological characteristics of P. xylostella when such traits were evaluated together, without directly affecting the insect behavior.

scholarly journals Toxicity and Sublethal Effect of Farnesyl Acetate on Diamondback Moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Norazila Yusoff ◽  
Idris Abd Ghani ◽  
Nurul Wahida Othman ◽  
Wan Mohd Aizat ◽  
Maizom Hassan
Keyword(s):  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Sublethal Effect ◽  
Sublethal Concentration ◽  
Pupal Weight ◽  
Control Group ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Female Ratio

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cruciferous vegetables worldwide. In this study, we evaluated the properties of selected farnesyl derivative compounds against P. xylostella. The toxicity and sublethal concentration (LC50) of farnesyl acetate, farnesyl acetone, farnesyl bromide, farnesyl chloride, and hexahydrofarnesyl acetone were investigated for 96 h. The leaf-dip bioassays showed that farnesyl acetate had a high level of toxicity against P. xylostella compared to other tested farnesyl derivatives. The LC50 value was 56.41 mg/L on the second-instar larvae of P. xylostella. Then, the sublethal effects of farnesyl acetate on biological parameters of P. xylostella were assessed. Compared to the control group, the sublethal concentration of farnesyl acetate decreased pupation and emergence rates, pupal weight, fecundity, egg hatching rate, female ratio, and oviposition period. Furthermore, the developmental time of P. xylostella was extended after being exposed to farnesyl acetate. Moreover, the application of farnesyl acetate on P. xylostella induced morphogenetic abnormalities in larval–pupal intermediates, adults that emerged with twisted wings, or complete adults that could not emerge from the cocoon. These results suggested that farnesyl acetate was highly effective against P. xylostella. The sublethal concentration of farnesyl acetate could reduce the population of P. xylostella by increasing abnormal pupal and adults, and by delaying its development period.

Susceptibility of field populations of the diamondback moth, Plutella xylostella, to a selection of insecticides in Central China

2016 ◽  
Vol 132 ◽  
pp. 38-46 ◽  
Author(s):  
Shuzhen Zhang ◽  
Xiaolei Zhang ◽  
Jun Shen ◽  
Kaikai Mao ◽  
Hong You ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Central China ◽  
Selection Of

scholarly journals Effects of food and sucralfate on a single oral dose of 500 milligrams of levofloxacin in healthy subjects.

1997 ◽  
Vol 41 (10) ◽  
pp. 2196-2200 ◽  
Author(s):  
L J Lee ◽  
B Hafkin ◽  
I D Lee ◽  
J Hoh ◽  
R Dix
Keyword(s):  
Oral Dose ◽  
Healthy Subjects ◽  
High Fat ◽  
Time Curve ◽  
Mean Values ◽  
Treatment Groups ◽  
The Mean ◽  
The Individual ◽  
Individual Profiles ◽  
Fat Meal

The effects of food and sucralfate on the pharmacokinetics of levofloxacin following the administration of a single 500-mg oral dose were investigated in a randomized, three-way crossover study with young healthy subjects (12 males and 12 females). Levofloxacin was administered under three conditions: fasting, fed (immediately after a standardized high-fat breakfast), and fasting with sucralfate given 2 h following the administration of levofloxacin. The concentrations of levofloxacin in plasma and urine were determined by high-pressure liquid chromatography. By noncompartmental methods, the maximum concentration of drug in serum (Cmax), the time to Cmax (Tmax), the area under the concentration-time curve (AUC), half-life (t1/2), clearance (CL/F), renal clearance (CLR), and cumulative amount of levofloxacin in urine (Ae) were estimated. The individual profiles of the drug concentration in plasma showed little difference among the three treatments. The only consistent effect of the coadministration of levofloxacin with a high-fat meal for most subjects was that levofloxacin absorption was delayed and Cmax was slightly reduced (Tmax, 1.0 and 2.0 h for fasting and fed conditions, respectively [P = 0.002]; Cmax, 5.9 +/- 1.3 and 5.1 +/- 0.9 microg/ml [90% confidence interval = 0.79 to 0.94] for fasting and fed conditions, respectively). Sucralfate, which was administered 2 h after the administration of levofloxacin, appeared to have no effect on levofloxacin's disposition compared with that under the fasting condition. Mean values of Cmax and AUC from time zero to infinity were 6.7 +/- 3.2 microg/ml and 47.9 +/- 8.4 microg x h/ml, respectively, following the administration of sucralfate compared to values of 5.9 +/- 1.3 microg/ml and 50.5 +/- 8.1 microg x h/ml, respectively, under fasting conditions. The mean t1/2, CL/F, CLR, and Ae values were similar among all three treatment groups. In conclusion, the absorption of levofloxacin was slightly delayed by food, although the overall bioavailability of levofloxacin following a high-fat meal was not altered. Finally, sucralfate did not alter the disposition of levofloxacin when sucralfate was given 2 h after the administration of the antibacterial agent, thus preventing a potential drug-drug interaction.

scholarly journals Variability of morphometric leaf characteristics of black poplar from the area of Vojvodina

2014 ◽  
pp. 63-72 ◽  
Author(s):  
Dijana Cortan ◽  
Mirjana Sijacic-Nikolic ◽  
Radmila Knezevic
Keyword(s):  
Morphological Differentiation ◽  
Morphometric Parameters ◽  
Specific Gene ◽  
Considerable Variability ◽  
Mean Values ◽  
Interpopulation Variability ◽  
Black Poplar ◽  
Significant Difference ◽  
The Mean ◽  
Two Populations

A morphological study of intra and interpopulation variability of black poplar leaves was conducted in two populations in the area of Vojvodina. Nine morphometric parameters of leaves have been analyzed. The results indicate that there is considerable variability within and between the populations. Morphological differentiation is clearly represented with the average values of analyzed parameters and a statistically significant difference between the mean values. On the basis of the obtained data, it has been concluded that the variability within the two populations is much more expressed than the variability between them. The uniformity of environmental conditions of the studied locations indicates that this variability is a consequence of the specific gene pool of the studied populations.

scholarly journals Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

2010 ◽  
Vol 3 (6) ◽  
pp. 1629-1646 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  
Keyword(s):  
Cross Sections ◽  
Measuring Instruments ◽  
Mean Values ◽  
Straight Line ◽  
Tropospheric No2 ◽  
The Mean ◽  
Almost All ◽  
Level Of Agreement ◽  
Selection Of ◽  
Differential Spectroscopy

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.

Evaluation of resistance, cross-resistance and synergism of abamectin and teflubenzuron in a multi-resistant field population of Plutella xylostella (Lepidoptera: Plutellidae)

1997 ◽  
Vol 87 (5) ◽  
pp. 481-486 ◽  
Author(s):  
M. Iqbal ◽  
D.J. Wright
Keyword(s):  
Plutella Xylostella ◽  
Maleic Acid ◽  
Diamondback Moth ◽  
Laboratory Strain ◽  
Piperonyl Butoxide ◽  
Diethyl Ester ◽  
Cross Resistance ◽  
Glutathione S Transferases ◽  
Pre Treatment ◽  
Selection Of

AbstractThe efficacy of abamectin (AgrimecR) and teflubenzuron (NomoltR) was assessed by leaf-dip bioassay against larvae of the diamondback moth, Plutella xylostella Linnaeus from a population (SERD3) collected originally in lowland Malaysia in December 1994. Evidence for resistance to both abamectin and teflubenzuron was found in the F7 generation (LC50 ratio of 60 and 24 respectively compared with a laboratory, insecticide-susceptible strain). Selection of sub-populations of SERD3 (F7–F9) with abamectin and teflubenzuron increased the LC50 ratio to 220 and 360 respectively and estimates of realized heritability [h2] were high (c. 0.8 and 0.9) for both compounds. There was no cross-resistance between these compounds in the abamectin and teflubenzuron-selected sub-populations but some indication of negatively-correlated resistance. Topical application of the synergists piperonyl butoxide, S,S,S-tributylphosphorotrithioate and maleic acid diethyl ester to the laboratory strain had no significant effect on the toxicity of abamectin or teflubenzuron in subsequent leaf-dip assays. In contrast, pre-treatment with piperonyl butoxide and S,S,S-tributylphosphorotrithioate significantly increased the toxicity of abamectin (c. 4- and 3-fold) and teflubenzuron (c. 7- and 19-fold) in the abamectin and teflubenzuron-selected sub-populations of SERD3, suggesting that microsomal monoxygenases and/or esterases may be involved in resistance. Pre-treatment with maleic acid diethyl ester only increased the toxicity of abamectin by c. 2-fold and had no significant effect on the toxicity of teflubenzuron, providing limited evidence for the involvement of glutathione-S-transferases in resistance to the former compound alone.

scholarly journals Selection of Trichogramma species for controlling the Diamondback moth

2008 ◽  
Vol 26 (2) ◽  
pp. 259-261 ◽  
Author(s):  
Dirceu Pratissoli ◽  
Ricardo A Polanczyk ◽  
Anderson M Holtz ◽  
Leandro P Dalvi ◽  
Alexandre F Silva ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Egg Parasitoids ◽  
Biological Characteristics ◽  
Parasitism Rate ◽  
Trichogramma Species ◽  
The One ◽  
Selection Of

Biological characteristics of the egg parasitoids Trichogramma acacioi, T. atopovirilia, and T. bennetti were studied to select the one with better performance on the control of the Diamondback moth, Plutella xylostella. Parasitism rate, viability, and sex ratio were studied. Parasitism rate ranged from 1.67 to 41.33%. T. atopovirilia and T. acacioi were respectively the most and less aggressive species. The viability ranged from 6.20% for T. acacioi to 53.34% for T. atopovirilia. There were no differences on sex ratio (p<0.05) that remained above 0,88. T. atopovirilia was the species with best performance in the laboratory when rearing on the Diamondback moth eggs.

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