Inheritance, Stability, and Lack-of-Fitness Costs of Field-Selected Resistance to Bacillus thuringiensis in Diamondback Moth (Lepidoptera: Plutellidae) from Florida

1997 ◽  
Vol 90 (3) ◽  
pp. 732-741 ◽  
Author(s):  
Juliet D. Tang ◽  
Smadar Gilboa ◽  
Richard T. Roush ◽  
Anthony M. Shelton
Keyword(s):  
Bacillus Thuringiensis ◽  
Diamondback Moth ◽  
Fitness Costs

Fitness Costs of Resistance to Bacillus thuringiensis in the Diamondback Moth (Plutella xylostella)

Evolution ◽  
1994 ◽  
Vol 48 (1) ◽  
pp. 197 ◽  
Author(s):  
Francis R. Groeters ◽  
Bruce E. Tabashnik ◽  
Naomi Finson ◽  
Marshall W. Johnson
Keyword(s):  
Bacillus Thuringiensis ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Fitness Costs

scholarly journals Genes and environment interact to determine the fitness costs of resistance to Bacillus thuringiensis

2005 ◽  
Vol 272 (1571) ◽  
pp. 1519-1524 ◽  
Author(s):  
Ben Raymond ◽  
Ali H Sayyed ◽  
Denis J Wright
Keyword(s):  
Bacillus Thuringiensis ◽  
Diamondback Moth ◽  
Poor Quality ◽  
Larval Competition ◽  
Fitness Costs ◽  
Varietal Resistance ◽  
Resistant Phenotype ◽  
Genes And Environment ◽  
Resistant Population ◽  
Cost Of Resistance

Genes which provide resistance to novel challenges such as pesticides, toxins or pathogens often impose fitness costs on individuals with a resistant phenotype. Studies of resistance to Bacillus thuringiensis and its insecticidal Cry toxins indicate that fitness costs may be variable and cryptic. Using two field populations (Karak and Serd4) of the diamondback moth, Plutella xylostella , we tested the hypothesis that the costs associated with resistance to the B. thuringiensis toxin Cry1Ac would be evident when insects were grown under poor environmental conditions, namely limited or poor quality resources. On a poor quality resource, a cultivar of Brassica oleracea var. capitata with varietal resistance to P. xylostella , only one resistant population, Karak, showed reduced fitness. Conversely, when we limited a high quality resource, Brassica pekinensis , by imposing larval competition, only resistant Serd4 insects had reduced survival at high larval densities. Furthermore, Cry1Ac resistance in Serd4 insects declined when reared at high larval densities while resistance at low densities fluctuated but did not decline significantly. These results confirm the hypothesis that resistance costs can appear under stressful conditions and demonstrate that the fitness cost of resistance to Bacillus thuringiensis can depend on the particular interaction between genes and the environment.

scholarly journals Host plant and population determine the fitness costs of resistance to Bacillus thuringiensis

2006 ◽  
Vol 3 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Ben Raymond ◽  
Ali H Sayyed ◽  
Denis J Wright
Keyword(s):  
Bacillus Thuringiensis ◽  
Host Plant ◽  
Environmental Quality ◽  
Species Interactions ◽  
Diamondback Moth ◽  
Larval Survival ◽  
Plant Quality ◽  
Relative Fitness ◽  
Fitness Costs ◽  
Fitness Parameters

Novel adaptations often cause pleiotropic reductions in fitness. Under optimal conditions individual organisms may be able to compensate for, or reduce, these fitness costs. Declining environmental quality may therefore lead to larger costs. We investigated whether reduced plant quality would increase the fitness costs associated with resistance to Bacillus thuringiensis in two populations of the diamondback moth Plutella xylostella . We also measured the rate of decline in resistance on two host-plant ( Brassica ) species for one insect population (Karak). Population×plant species interactions determined the fitness costs in this study. Poor plant quality increased the fitness costs in terms of development time for both populations. However, fitness costs seen in larval survival did not always increase as plant quality declined. Both the fitness and the stability experiment indicated that fitness costs were higher on the most suitable plant for one population. Theoretically, if the fitness cost of a mutation interacts additively with environmental factors, the relative fitness of resistant insects will decrease with environmental quality. However, multiplicative costs do not necessarily increase with declining quality and may be harder to detect when fitness parameters are more subject to variation in poorer environments.

Effect of Treatment With 3-Octylthio-1,1,1-Trifluoropropan-2-One in the Diamondback Moth (Lepidoptera: Plutellidae) to the Toxicity of Diafenthiuron, Indoxacarb, and Bacillus thuringiensis

2020 ◽  
Vol 113 (3) ◽  
pp. 1419-1425 ◽  
Author(s):  
Jingfei Huang ◽  
Sufen Tian ◽  
Ke Ren ◽  
Yong Chen ◽  
Shuo Lin ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Juvenile Hormone ◽  
Combination Treatment ◽  
Insect Pest ◽  
Diamondback Moth ◽  
Treatment Method ◽  
Juvenile Hormone Esterase ◽  
Trifluoromethyl Ketones ◽  
Insecticide Synergist ◽  
Almost All

Abstract The diamondback moth, Plutella xylostella (L.), is a worldwide insect pest of cruciferous crops. Although insecticides have long been used for its control, diamondback moth rapidly evolves resistance to almost any insecticide. In insects, juvenile hormone (JH) is critically involved in almost all biological processes. The correct activity of JH depends on the precise regulation of its titer, and juvenile hormone esterase (JHE) is the key regulator. Thus, JH and JHE have become important targets for new insecticide development. Trifluoromethyl ketones are specific JHE inhibitors, among which 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) has the highest activity. The interaction effects between pretreatment with or combination of OTFP and the insecticides diafenthiuron, indoxacarb, and Bacillus thuringiensis (Bt) were investigated in diamondback moth larvae to determine OTFP’s potential as an insecticide synergist. In third-instar larvae, both pretreatment and combination treatment with OTFP decreased or antagonized the toxicities of diafenthiuron, indoxacarb, and Bt at all set concentrations. In fourth-instar larvae, combination treatment with OTFP decreased or antagonized the toxicities of diafenthiuron and indoxacarb at all set concentrations. However, it increased or synergized the toxicity of Bt at lower concentrations despite the limited effect at higher concentrations. Our results indicated that the effect of OTFP on the toxicities of insecticides varied with the type and concentration, larval stage, and treatment method. These findings contribute to the better use of OTFP in diamondback moth control.

Sign in / Sign up

Export Citation Format

Share Document