The frequency distribution of parasitoid viability in each
treatment was graphically displayed by histogram analysis. Wasp
viability in corn strain larvae reared on corn approximated a broad
bell-shaped pattern with a peak between 0.6 and 0.9 proportion of
adult recovery (Fig. 1A). A stargrass diet produced a more irregular
configuration with adult recovery levels shifted leftward. These effects
were more pronounced with the rice-strain larvae. Wasp viability
on rice-strain larvae reared on corn had a clear peak
between 0.9 and 1.0 adult recovery, with a long leftward tail. When
raised on stargrass, the frequency pattern again became irregular