Populations that were less sensitive to imidacloprid had a shallower and more heterogeneous response. There was no evidence of any shift toward tolerance to imidacloprid after one season of selection pressure. Another explanation is that we collected overwintered beetles on imidacloprid-treated plants and even though the exposure time was relatively short, we collected survivors already selected by imidacloprid. Return to document Figure 2. Location of CPB populations assayed for imidacloprid susceptibility.
Populations are group according to their resistance to pyrethroids and organophosphates.
Figure 3 is missing Figure 3 Scatter plot of susceptibility to imidacloprid and esfenvalerate in the CPB populations Return to document Figure 4. Scatter plot of susceptibility to imidacloprid and azinphosmethyl in the CPB populations. Return to document Table 1. Susceptibility of Colorado potato beetle populations to imidacloprid, esfenvalerate, and azinphosmethyl. Populations are listed in order of most to least susceptible to imidacloprid.