The third experiment was a choice study in which the wasp was
simultaneously exposed to larvae of both strains. The method was
the same as the no-choice experiment except that one larva of each
strain was placed on the tested host plant. Larvae were
distinguished by foreleg clipping. We allowed 48 h for oviposition
and the host larvae were then separated to avoid cannibalization
and placed in 1-oz acrylic cups to complete wasp development
and pupation. In total 106 larvae fed corn plants were used (53 larvae
from each strain) and 80 larvae fed stargrass (40 larvae from
each strain) were used. The position on each larva of E. platyhypenae
egg clutches and the number of eggs laid per larva was
recorded for both the no-choice and choice experiments. These last
two experiments allowed us to assess egg allocation, host viability,
and parasitoid viability and development, under choice and
no-choice treatments.