Abstract
The distribution of resistant individuals is determined by the amount of movement between populations. The differential rate of dispersal of a susceptible and a pesticide-resistant strain could influence the resistance dynamics under field conditions. The dispersal rate and dispersal efficiency of the susceptible and propargite-resistant strains of Tetranychus urticae were measured in separate-release and mixed-release experiments. The diffusion coefficient (D) of both strains did not differ significantly (P > 0.344) and an estimate of the asymptotic rate of advance (2 √ rD) (for one generation) was estimated at 0.1047 and 0.0930 cm per degree day for the susceptible and propargite-resistant strains, respectively. The dispersal efficiency of the two strains differed significantly (P < 0.005) as more susceptible mites than propargite-resistant mites crossed into specified zones more quickly after 290 and 366 degree days. Significantly (P < 0.05) higher number of susceptible adults, immatures and eggs were found in the outer most zone of an arena as compared to that of the propargite-resistant mites. The bioassay of the two strains showed a similar pattern of the spread of the adult females across the specified zones in the mixed-release experiment. The relatively lower dispersive tendency of the propargite-resistant T. urticae and the smaller proportion of adult females exhibiting that behaviour increase the chances of developing resistant ‘hotspots’ in field specially after an acaricide application.
| Original language | English |
|---|---|
| Pages (from-to) | 75-80 |
| Number of pages | 6 |
| Journal | Journal of Asia-Pacific Entomology |
| Volume | 21 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Mar 2018 |
Keywords
- Acaricide resistance
- Dispersal
- Dispersion patterns
- Pesticide resistance
- Resistance dynamics
- Tetranychus urticae
ASJC Scopus subject areas
- Insect Science