The combination of rice-strain larvae and a stargrass diet
appears to be particularly detrimental to the larval host and parasitoid,
as it is associated with higher mortalities and smaller sizes
for both. The reasons for this are unclear, but it does not appear to
be due to differences in larval size. The rice-strain larvae grown on
stargrass were equal in size to both strains reared on corn, indicating
that size was not a determining factor for the observed differences
in parasitoid mortality and adult size. Furthermore, the
largest larvae were found with the corn-strain grown on stargrass
(by approximately 30%), yet this treatment was not associated with
higher attractiveness to parasitism, wasp viability, or adult wasp
size. These observations suggest that the quality rather than size
of the larvae is more determinative of parasitoid performance. Of
particular interest is the possibility of tritrophic interactions where
the corn diet increases the relative attractiveness of the corn strain
(but not rice strain) to parasitism