Figure 1.
Percentage of all cotton hectares accounted for by Bt cotton in the Yangtze River Valley, 2000–2010.
Figure 2.
Pink bollworm resistance monitoring field sites in the Yangtze River Valley.
Figure 3.
Concentration of Bt toxin Cry1Ac killing 50% of pink bollworm larvae (LC50).
Field strains were collected from the resistance monitoring sites in the Yangtze River Valley during 2005–2010. The bars represent the standard error of the mean LC50 for the field-derived strains tested in a given year (n = 4 to 13 strains per year). QJ-S is a susceptible lab strain that was tested each year as an internal standard.
Table 1.
Responses to Bt toxin Cry1Ac of pink bollworm larvae from the Yangtze River Valley from 2005 to 2007.
Table 2.
Responses to Bt toxin Cry1Ac of pink bollworm larvae from the Yangtze River Valley from 2008 to 2010.
Figure 4.
Percentage of pink bollworm field populations with survivors at the diagnostic concentration (9 µg Cry1Ac per ml diet).
The number of field populations tested in the Yangtze River Valley was 4 in 2005, 13 in 2006, 7 in 2007, 8 in 2008, 8 in 2009, and 11 in 2010 (see Tables 1 and 2).
Table 3.
Survival on bolls of Bt and non-Bt cotton of pink bollworm larvae from a susceptible strain (QJ-S) and a lab-selected resistant strain (YZP06-R).