Bulletin of Entomological Research (2014) 104, 88-96

L.M. Ribeiro, V. Wanderley-Teixeira, H.N. Ferreira, A.A. Teixeira and H.A. Siqueira (2014)
Fitness costs associated with field-evolved resistance to chlorantraniliprole in Plutella xylostella (Lepidoptera: Plutellidae)
Bulletin of Entomological Research 104 (1), 88-96
Abstract: Plutella xylostella (L.) is the most important pest of Brassicaceae worldwide, with a recent estimate of US$ 4-5 billion expenditure for the control of this insect. A case of very high resistance of this pest to chlorantraniliprole was recently associated with reduced efficacy in a Brazilian field of Brassica spp. Although diamide resistance has been characterized, the fitness of insects due to such resistance has yet to be examined. Therefore, in this study, biological parameters were assessed in both susceptible and resistant strains of P. xylostella subjected to sublethal chlorantraniliprole concentrations. The field strain showed high resistance to chlorantraniliprole (RR₅₀=27,793-fold), although resistance rapidly decreased in the first generations, showing instability. The exposure of susceptible and resistant larvae to their respective LC₁, LC₁₀, and LC₂₅ values led to an increased duration of the larval and pupae phases and reduced weight in both strains; however, no significant differences in pupal viability across the treatments were observed. The resistant insects presented significantly lower larval weight and fecundity and higher larval and pupal periods, hatchability, and male longevity when not exposed to chlorantraniliprole, suggesting a fitness cost associated with resistance. In addition, resistant females showed a significantly higher egg-laying period and longevity at LC₂₅, whereas the males lived longer at LC₁. Chlorantraniliprole negatively impacted the biological parameters of both strains tested, although these effects were more relevant to the resistant insects. Resistant P. xylostella showed negative and positive biological trade-offs when compared with the susceptible individuals in both the absence and presence of chlorantraniliprole. Despite the important role that these trade-offs may play in the evolution of resistance to chlorantraniliprole, practical applications still depend on such information as the dominance of fitness costs and resistance.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Herbert A.A. Siqueira

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella