Corn pollen

Anaya, A. L., Hernandez-Bautista, B. E., Jimenez-Estrada, M. and Velasco-Ibarra, L. (1992). Phenylacetic acid as a phytotoxic compound of corn pollen. Journal of Chemical Ecology 18 897-905. 

Ortega, R.C., Anaya, A.L. and Ramos, L. (1988). Effects of allelopathic compounds of corn pollen on respiration and cell division of watermelon. Journal of Chemical Ecology 14 71-86. 

Pimentel, DavidS., and Peter H. Raven. 2000. Bt corn pollen impacts on nontarget Lepidoptera Assessment of effects in nature. Proceedings of the National Academy of Sciences USA 97(15) 8198-8199. 

Concerns over the safety of transgene introduction into environment was sensitized early in the GMO debate with significant focus on the potential toxicity of Bt endotoxins to monarch butterfly [Danaus plexippus) larvae exposed to transgenic pollen. Early data suggested that Bt corn pollen could result in potentially significant reactions in the monarch gut. 

The early USDA efforts to isolate hormones from corn pollen were not very fruitful. The USDA finally terminated the pollen research project in 1944 due to lack of (a) suitable plant bioassay systems to detect the hormones present in pollen and (b) proper analytical methods to isolate and identify the pollen hormones. 

Ecological concerns are real as we do not know what may occur with the widespread propagation of transgenic plants. There were initial fears that Bt corn was toxic not only to the European corn borer but also to the monarch butterfly larvae that may eat milkweed leaves laced with Bt corn pollen. However, EPA studies dismissed this threat. It is possible that other insects, not intended as targets of bioengineered proteins, may also be affected. It is absolutely essential that these ecological issues be addressed. However, these are not food safety issues. The same concerns occur with the widespread use of organic pesticides relative to runoff and water pollution. Both must be addressed on their own merits. 

In response to public concerns raised by recent monarch butterfly/Bt-corn pollen studies [26, 27], tests are also under way to compare the respective effects of purified lepidopteran-active Bt toxins, of a Bt biopesticide preparation, and of a conventional chemical pesticide commonly used on corn and potentially present when pollen is produced (M.H. Pham-Delegue, unpubhshed data). Such work is expected to assess the biosafety correlates of the different methods used for crop protection, rather than simply comparing the effects of GM plants versus control plants, which is not agronomically realistic. 

Jesse, L.C.H. and Obrycki, J.J. (2000). Field deposition of Bt transgenic corn pollen Lethal effects on the monarch butterfly. Oecologia, available at athene.em.springer.de. 

Although Bt corn pollen imder certain conditions has the potential of adversely affecting the population levels of monarch butterflies and other non-target Lepidoptera, we consider these impacts to be minimal when compared with habitat loss and the widespread use of pesticides throughout the ecosystem. 

Impact of Bacillus ihuringiensis Corn Pollen on Monarch Butterfly Populations... 

Duan, J.J., G. Head, M.J. McKee, T.E. Nickson, J.W. Martin, and F.S. Sayegh. 2002 Evaluation of transgenic corn pollen expressing Cry3Bbl protein on a non-target ladybird beetle, Coleomegilla maculata. Entomol. Exp. Applic. 104 271-280. 

Hansen Jesse, L.C. and J.J. Obrycki. 2002. Assessment of the non-target effects of transgenic Bt corn pollen and anthers on the milkweed tiger moth, Euchatias egle Drury (Lepidoptera Arctiidae). J. Kansas Entomol. Soc. 75 55-58. 

Oberhauser, K.S., M.D. Prysby, H.R. Mattila, D.E. Stanley-Horn, M.K. Sears, G. Dively, E. Olson, J.M. Pleasants, W.F. Lam, and R.L. Hellmich. 2001. Temporal and spatial overlap between monarch larvae and corn pollen. Proc. Natl. Acad. Sci. (USA) 98 11913-11918. 

Raynor, G.S., J.V. Hayes, and E.C. Ogden. 1972. Dispersion and deposition of corn pollen from experimental sources. Agron. J. 64 420-426. 

Shirai, Y. and M. Takahashi. 2005. Effects of transgenic corn pollen on a non-target lycaenid butterfly, Pseudozizeeria maha. Appl. Entomol. Zool. 40 151-159. 

Wolt, J.D., R.K.D. Peterson, P. Bystrak, and T. Meade. 2003. A screening level approach for non-target risk assessment transgenic Bt corn pollen and the monarch butterfly (Lepidoptera Danaidae). Environ. Entomol. 32 237-246. 

Zangerl, A.R., D. McKenna, C.L. Wraight, M. Carroll, P. Ficarello, R. Warner, and M.R. Berenbaum. 2001. Effects of exposure to event 176 Bacillus thuringiensis corn pollen on monarch and black swallowtail caterpillars under field conditions. Proc. Natl. Acad. Sci. (USA) 98 11908-11912. 

Obrycki, J. 1994. Feeding, Development, and Survival of the Lady Beetle Predator Coleomegilla maculata (Coleoptera coccinellidae) on Transgenic "Bt" Maize (Corn) Pollen Final Report Lab Proj No. PHO176/0194 ISU. Unpublished study prepared by Iowa State University, Department of Entomology. 62 p. 

Maggi, V. 1994. Evaluation of the Dietary Effect(s) of Transgenic Bt Maize (Corn) Pollen (Sample PH0176-0294) on Honeybee Development Lab Project Number CAR 176-94. Unpublished study prepared by California Agricultural Research, Inc. 57 p. 

Palmer, S. and J. Beavers. 1997. Cry9C Protein in Corn Pollen A Dietary Toxicity Study with the Ladybird Beetle (Hippodamia convergens) (Final Report) Lab Proj No. 452-101 452/102496/LBLC/SUB452. Unpublished study prepared by Wildlife International Ltd. 36 p. OPPTS 885-4350. ... 

Drottar, K. and H. Krueger. 1999. Bacillus thuringiensis Protein 11098 in Corn Pollen A 48-Hour Static-Renewal Acute Toxicity with the Cladoceran Daphnia magna) Lab Project Number WL-98-295 16163 139A-236. Unpublished study prepared by Monsanto Company and Wildlife International Ltd. 31 p. 

Duan, J., G. Head, M. McKee, et al. 2001. Dietary Effects of Transgenic Bacillus thuringiensis (Bt) Corn Pollen Expressing a Variant of Cry3Bbl Protein on Adults of the Ladybird Beetle, Coleomegilla maculata Lab Project Number MSL-16936 00-01-39-37. Unpublished study prepared by Monsanto, Co. 35 p. 

Sears, M. and H. Mattila. 2001. Determination of the Toxicity of Corn Pollen Expressing a CrySBbl Variant Protein to First Instar Monarch Butterfly Larvae Danaus plexippus) via Laboratory Bioassay Lab Project Number MSL-17235 01-01-39-26. Unpublished study prepared by University of Guelph. 33 p. 

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