0 ( 0 ) P : 000-000 Type: ARTICLE Literature: oryza Field: abstract Doc ID: pub00000000 Accession (PMID): 00000000 Matching Sentences: [ Sen. 0, subscore: 0.00 ]: However , elimination of Bt-susceptible prey and hosts in Bt crops could reduce predator and parasitoid abundance and thereby disrupt biological control of other herbivorous pests . Here we report results of a field study evaluating the effects of Bt sprays on non-target terrestrial herbivore and natural enemy assemblages from three rice ( Oryza sativa L ) fields on Luzon Island , Philippines . Because of restrictions on field-testing of transgenic rice , Bt sprays were used to remove foliage-feeding lepidopteran larvae that would be targeted by Bt rice . Data from a 000-taxa Philippines-wide food web , matched abundance plots , species accumulation curves , time-series analysis , and ecostatistical tests for species richness and ranked abundance were used to compare different subsets of non-target herbivores , predators , and parasitoids in Bt sprayed and water-sprayed ( control ) plots . For whole communities of terrestrial predators and parasitoids , Bt sprays altered parasitoid richness in 0 of 0 sites and predator richness in 0 of 0 sites , as measured by rarefaction ( in half of these cases , richness was greater in Bt plots ) , while Spearman tests on ranked abundances showed that correlations , although significantly positive between all treatment pairs , were stronger for predators than for parasitoids , suggesting that parasitoid complexes may have been more sensitive than predators to the effects of Bt sprays . Species accumulation curves and time-series analyses of population trends revealed no evidence that Bt sprays altered the overall buildup of predator or parasitoid communities or population trajectories of non-target herbivores ( planthoppers and leafhoppers ) nor was evidence found for bottom-up effects in total abundances of non-target species identified in the food web from the addition of spores in the Bt spray formulation . When the same methods were applied to natural enemies ( predators and parasitoids ) of foliage-feeding lepidopteran and non-lepidopteran ( homopteran , hemipteran and dipteran ) herbivores , significant differences between treatments were detected in 0 of 00 cases . However , no treatment differences were found in mean abundances of these natural enemies , either in time-series plots or in total ( seasonal ) abundance . Analysis of guild-level trajectories revealed population behavior and treatment differences that could not be predicted in whole-community studies of predators and parasitoids . 