Prey-mediated effects of transgenic cry2Aa rice on the spider Hylyphantes graminicola, a generalist predator of Nilapavarta lugens

摘要

Concerns have been raised that transgenic Bt rice may have adverse effects on non-target natural enemies. The spider Hylyphantes graminicola is a generalist predator, and may be exposed to the insecticidal proteins expressed in Bt rice through ingestion of rice pests. Survival, developmental time, body weight and fecundity of the spider did not differ when fed on Nilapavarta lugens reared either on transgenic cry2Aa or nontransgenic rice based on a tritrophic bioassay. Similarly, the functional response of H. graminicola did not differ between Bt or non-Bt rice. Cry2Aa protein did not accumulate in this spider when the prey N. lugens fed on transgenic cry2Aa rice. No significant differences in population density and population dynamics were observed between H. graminicola in transgenic cry2Aa and nontransgenic rice fields during a three-year field investigation. The results indicates that the life-table parameters tested in the present study, population dynamics and density of H. graminicola were not affected by transgenic cry2Aa rice.