Field and semifield evaluation of impacts of transgenic canola pollen on survival and development of worker honey bees.

A 2-yr field trial (2001 and 2002) and 1-yr semifield trial (2002) were conducted to evaluate the effect of transgenic herbicide (glyphosate) -tolerant canola Brassica napus L. pollen on larval and adult honey bee, Apis mellifera L., workers. In the field trial, colonies of honey bees were moved to transgenic or nontransgenic canola fields (each at least 40 hectares) during bloom and then sampled for larval survival and adult recovery, pupal weight, and hemolymph protein concentrations. No differences in larval survival, adult recovery, and pupal weight were detected between colonies placed in nontransgenic canola fields and those in transgenic canola fields. Colonies placed in the transgenic canola fields in the 2002 field experiment showed significantly higher hemolymph protein in newly emerged bees compared with those placed in nontransgenic canola field; however, this difference was not detected in the 2001 field experiment. In the semifield trial, bee larvae were artificially fed with bee-collected transgenic and nontransgenic canola pollen and returned to their original colonies. Larval survival, pupal survival, pupal weight, and hemolymph protein concentration of newly emerged adults were measured. There were no significant differences in any of the parameters measured between larvae that were fed transgenic canola pollen and those fed nontransgenic corn pollen. Results from this study suggest that transgenic canola pollen does not have adverse effects on honey bee development and that the use of transgenic canola dose not pose any threat to honey bees.