Assessing the Single and Combined Toxicity of Chlorantraniliprole and Bacillus thuringiensis (GO33A) against Four Selected Strains of Plutella xylostella (Lepidoptera: Plutellidae), and a Gene Expression Analysis

Concerns about resistance development to conventional insecticides in diamondback moth (DBM) Plutella xylostella (L.), the most destructive pest of Brassica vegetables, have stimulated interest in alternative pest management strategies. The toxicity of Bacillus thuringiensis subsp. aizawai (Bt GO33A) combined with chlorantraniliprole (Chl) has not been documented. Here, we examined single and combined toxicity of chlorantraniliprole and Bt to assess the levels of resistance in four DBM strains. Additionally, enzyme activities were tested in field-original highly resistant (FOH-DBM), Bt-resistant (Bt-DBM), chlorantraniliprole-resistant (CL-DBM), and Bt + chlorantraniliprole-resistant (BtC-DBM) strains. The Bt product had the highest toxicity to all four DBM strains followed by the mixture of insecticides (Bt + Chl) and chlorantraniliprole. Synergism between Bt and chlorantraniliprole was observed; the combination of Bt + (Bt + Chl) (1:1, LC50:LC50) was the most toxic, showing a synergistic effect against all four DBM strains with a poison ratio of 1.35, 1.29, 1.27, and 1.25. Glutathione S-transferase (GST) and carboxyl-esterase (CarE) activities showed positive correlations with chlorantraniliprole resistance, but no correlation was observed with resistance to Bt and Bt + Chl insecticides. Expression of genes coding for PxGST, CarE, AChE, and MFO using qRT-PCR showed that the PxGST and MFO were significantly overexpressed in Bt-DBM. However, AChE and CarE showed no difference in the four DBM strains. Mixtures of Bt with chlorantraniliprole exhibited synergistic effects and may aid the design of new combinations of pesticides to delay resistance in DBM strains substantially.

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Insecticidal Effects of Organotin(IV) Compounds on Plutella Xylostella (L.) Larvae. II. Inhibitory Potencies Against Acetylcholinesterase and Evidence for Synergism in Tests With Bacillus Thuringiensis(BER.) and Malathion

Metal-Based Drugs ◽

10.1155/mbd.1994.1 ◽

1994 ◽

Vol 1 (1) ◽

pp. 1-17 ◽

Cited By ~ 4

Author(s):

Nazni W. Ahmad ◽

Tay Siew Huang ◽

S. Balabaskaran ◽

K. M. Lo ◽

V. G. Kumar Das

Keyword(s):

Bacillus Thuringiensis ◽

Plutella Xylostella ◽

Resistant Strain ◽

Synergistic Effects ◽

Diamondback Moth ◽

Ache Inhibition ◽

Microbial Insecticide ◽

In Vitro Inhibition ◽

Sublethal Concentrations

Features of pesticide synergism and acetylcholinesterase (AChE) inhibition (in vitro) were studied using a selected range of organotin compounds against the early 4th instar larvae of a highly resistant strain of the diamondback moth (DBM), Plutella xylostella, a major universal pest of cruciferous vegetables.Fourteen triorganotin compounds were evaluated for their ability to enhance the toxicity of the microbial insecticide, Bacillus thuringiensis (BT) and of the commercial insecticide, Malathion to Plutella xylostella larvae. Supplemental synergism was observed with triphenyl- and tricyclopentyltin hydroxides in combinations with Bacillus thuringiensis. Increased synergism was observed with an increase in the number of cyclopentyl groups on tin in the mixed series, CypnPh3-n SnX, where X = OH, and 1-(1,2,4-triazolyl). The combination of (p-chlorophenyl)diphenyltin N,N-dimethyldithiocarbamate at LD10 and LD25 concentrations with sublethal concentrations of Malathion as well as of tricyclohexyltin methanesulphonate at the 0.01% (w/v) concentration with Malathion exerted strong synergistic effects (supplemental synergism) with toxicity index (T.I) values of 7.2, 19.8 and 10.1, respectively.Studies on the in vitro inhibition of acetylcholinesterase prepared from the DBM larvae showed that while most of the triorganotin Compounds tested were without effect on the enzyme, compounds containing the thiocarbamylacetate or the dithiocarbamylacetate moieties demonstrated appreciable levels of inhibition, being comparable in efficacy to commercial grades of Malathion and Methomyl.

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Biochemical Mechanisms, Cross-resistance and Stability of Resistance to Metaflumizone in Plutella xylostella

Insects ◽

10.3390/insects11050311 ◽

2020 ◽

Vol 11 (5) ◽

pp. 311

Author(s):

Jun Shen ◽

Zhao Li ◽

Dongyang Li ◽

Rumeng Wang ◽

Shuzhen Zhang ◽

...

Keyword(s):

Plutella Xylostella ◽

Diamondback Moth ◽

Management Strategies ◽

Detoxification Enzymes ◽

Cross Resistance ◽

Transferase Activity ◽

Glutathione S Transferase ◽

Obvious Effect ◽

Stability Of Resistance ◽

Biochemical Mechanisms

The diamondback moth, Plutella xylostella (L.) is an important pest of cruciferous crops worldwide. It has developed resistance to many conventional and novel insecticide classes. Metaflumizone belongs to the new chemical class of semicarbazone insecticides. To delay the development of metaflumizone resistance in P. xylostella and to guide insecticide use in the field, the biochemical mechanisms, cross-resistance spectrum, and stability of resistance to metaflumizone were studied in a laboratory-selected resistant strain (metaflu-SEL). Synergism tests with the carboxylesterase inhibitor triphenyl phosphate (TPP), the glutathione S-transferase depletor diethyl maleate (DEM), and the P450 inhibitor piperonyl butoxide(PBO) had no obvious effect on metaflumizone in the metaflu-SEL strain and the susceptible strain (SS) of P. xylostella, with synergism ratios that ranged from 1.02 to 1.86. Biochemical studies revealed that the cytochrome P450-dependent monooxygenase increased only 1.13-fold in the metaflu-SEL strain compared with the UNSEL stain; meanwhile, carboxylesterase and glutathione S-transferase activity showed no difference. These results suggest that these detoxification enzymes may be not actively involved in metaflumizone resistance. Furthermore, the metaflu-SEL population showed a moderate level of cross-resistance to indoxacarb (11.63-fold), but only very low cross-resistance to spinosad (1.75-fold), spinetoram (3.52-fold), abamectin (2.81-fold), beta-cypermethrin (0.71-fold), diafenthiuron (0.79-fold), chlorantraniliprole (2.16-fold), BT (WG-001) (3.34-fold), chlorfenapyr (0.49-fold), and chlorfluazuron (0.97-fold). Moreover, metaflumizone resistance decreased from 1087.85- to 1.23-fold in the metaflu-SEL strain after 12 generations without exposure to metaflumizone. These results are useful for formulating insecticide resistance management strategies to control P. xylostella and to delay the development of metaflumizone resistance in the field.

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Fitness costs and stability of resistance to Bacillus thuringiensis in a field population of the diamondback moth Plutella xylostella L.

Ecological Entomology ◽

10.1046/j.1365-2311.2001.00358.x ◽

2001 ◽

Vol 26 (5) ◽

pp. 502-508 ◽

Cited By ~ 59

Author(s):

Ali H. Sayyed ◽

Denis J. Wright

Keyword(s):

Bacillus Thuringiensis ◽

Plutella Xylostella ◽

Diamondback Moth ◽

Field Population ◽

Fitness Costs ◽

Stability Of Resistance

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Evaluation of Biological Activity of Bacillus thuringiensis Test Samples Using a Diet Incorporation Method with Diamondback Moth, Plutella xylostella(LINNAEUS)(Lepidoptera:Yponomeutidae)

Applied Entomology and Zoology ◽

10.1303/aez.28.513 ◽

1993 ◽

Vol 28 (4) ◽

pp. 513-524 ◽

Cited By ~ 21

Author(s):

Shoji ASANO ◽

Takeshi MARUYAMA ◽

Tomoko IWASA ◽

Akihiro SEKI ◽

Makoto TAKAHASHI ◽

...

Keyword(s):

Biological Activity ◽

Bacillus Thuringiensis ◽

Plutella Xylostella ◽

Diamondback Moth ◽

Incorporation Method

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Increased Responses of Phenoloxidase in Chlorantraniliprole Resistance of Plutella xylostella (Lepidoptera: Plutellidae)

Journal of Insect Science ◽

10.1093/jisesa/ieaa066 ◽

2020 ◽

Vol 20 (4) ◽

Author(s):

Nian-Meng Wang ◽

Jing-Jing Li ◽

Ze-Yu Shang ◽

Qi-Tong Yu ◽

Chao-Bin Xue

Keyword(s):

Plutella Xylostella ◽

Synergistic Effects ◽

Diamondback Moth ◽

Cruciferous Vegetables ◽

Transcriptional Expression ◽

Resistance Development ◽

Expression Levels ◽

Important Pest ◽

Resistant Strains

Abstract The diamondback moth (Plutella xylostella, DBM) is an important pest of cruciferous vegetables. The use of chlorantraniliprole has been essential in the management of the DBM. However, in many countries and areas, DBM has become highly resistant to chlorantraniliprole. Three different DBM strains, susceptible (S), chlorantraniliprole-selected (Rc), and field-collected (Rb) resistant strains/populations were studied for the role of phenoloxidase in resistance development to the insecticide. By assaying the activity of phenoloxidase (PO) in the three different DBM strains, the results showed that the PO activity in the Rc strain was increased significantly compared with the S strain. The synergistic effects of quercetin showed that the resistant ratio (RR) of the QRc larvae to chlorantraniliprole was decreased from 423.95 to 316.42-fold compared with the Rc larvae. Further studies demonstrated that the transcriptional and translational expression levels of PxPPO1 (P. xylostella prophenoloxidase-1 gene) and PxPPO2 (P. xylostella prophenoloxidase-2 gene) were increased to varying degrees compared with the S strain, such as the transcriptional expression levels of PxPPO2 were 24.02-fold that of the S strain. The responses of phenoloxidase were significantly different in chlorantraniliprole-resistant DBM.

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The effects of local selection versus dispersal on insecticide resistance patterns: longitudinal evidence from diamondback moth (Plutella xylostella (Lepidoptera: Plutellidae)) in Australia evolving resistance to pyrethroids

Bulletin of Entomological Research ◽

10.1017/s0007485307005494 ◽

2008 ◽

Vol 98 (2) ◽

pp. 145-157 ◽

Cited By ~ 28

Author(s):

N.M. Endersby ◽

P.M. Ridland ◽

A.A. Hoffmann

Keyword(s):

Gene Flow ◽

Plutella Xylostella ◽

Diamondback Moth ◽

Management Strategies ◽

Resistance Management ◽

Synthetic Pyrethroids ◽

Forage Crops ◽

Microsatellite Variation ◽

Resistance Evolution ◽

Local Selection

AbstractWhen strong directional selection acts on a trait, the spatial distribution of phenotypes may reflect effects of selection, as well as the spread of favoured genotypes by gene flow. Here we investigate the relative impact of these factors by assessing resistance to synthetic pyrethroids in a 12-year study of diamondback moth, Plutella xylostella, from southern Australia. We estimated resistance levels in populations from brassicaceous weeds, canola, forage crops and vegetables. Differences in resistance among local populations sampled repeatedly were stable over several years. Levels were lowest in samples from weeds and highest in vegetables. Resistance in canola samples increased over time as insecticide use increased. There was no evidence that selection in one area influenced resistance in adjacent areas. Microsatellite variation from 13 populations showed a low level of genetic variation among populations, with an AMOVA indicating that population only accounted for 0.25% of the molecular variation. This compared to an estimate of 13.8% of variation accounted for by the resistance trait. Results suggest that local selection rather than gene flow of resistance alleles dictated variation in resistance across populations. Therefore, regional resistance management strategies may not limit resistance evolution.

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