control. Bt maize, variety Novelis transgenic event MON810 (abbreviated Bt), which
synthesized the Cry1Ab protein insect control, was used in the third treatment. As host
plants (weeds) for standardized attraction of butterflies, we used the artificial plantation of
goosefoot (Chenopodium album) and mustard (Sinapis alba) within corn rows (Fig. 13.3).
Figure 13.1.Field trial design for testing the environmental impact of bioinsecticidal (Bt) corn
pollen or chemical insecticide use on nontarget butterflies. The cornfield trial was performed in an
area with European corn borer (ECB) infestation. The trial consisted of eight replications and three
treatments (INS¼chemical insecticide on a conventional ECB-susceptible variety, ISO¼conven-
tional ECB-susceptible variety without any pest ECB control, Bt¼GM corn with internal biopesti-
cide protection against ECB).
Figure 13.2.Collection of caterpillar larvae on weeds in cornfields. Presented are the median number
ofPlutella xylostella(diamondback moth caterpillars) on their host plantSinapis alba(white mustard)
in the three different treatment Bt corn (Bt) and the near-isogenic variety with (INS) and without
(ISO) chemical insecticide application. Larvae were collected before and at the end of pollen shed.
Results are pictured as box plots. Horizontal line indicates median of individuals per plot (eight repli-
cations for each treatment); box represents 75% of all values; upper and lower dashes represent 90% of
all values. Dots indicate extreme values.
316 FIELD TESTING OF TRANSGENIC PLANTS