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.