UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

 WASHINGTON, D.C. 20460

 OFFICE OF CHEMICAL SAFETY 

 AND POLLUTION PREVENTION 

SEPT 17 2010

MEMORANDUM 

 SUBJECT: BPPD Response to ABSTC* Comments on Proposed Terms and 

Conditions for 2010 Expiring Bt Corn Registrations. Data Required to 

Register Plant-Incorporated Protectants: Aquatic Invertebrates and 

Orius Testing Issues 

 

FROM: Zigfridas Vaituzis, Senior Scientist (signed 9-17-10) 

 Microbial Pesticides Branch 

 Biopesticides and Pollution Prevention Division, 7511P 

TO: Mike Mendelsohn, Senior Regulatory Action Leader 

 Microbial Pesticides Branch 

 Biopesticides and Pollution Prevention Division, 7511P 

 

*The ABSTC members are: Bayer CropScience; Dow AgroSciences LLC; Pioneer Hi-Bred 

International, a DuPont Company; Monsanto Company; and Syngenta Seeds, Inc 

I. AQUATIC INVERTEBRATE ISSUE

Background: 

As a result of a recently published study (Rosi-Marshall, et al. 2007) showing weight reduction in 

shredding caddis flies exposed to anti-lepidopteran Cry1A protein corn litter in a laboratory setting, 

EPA required the registrants of PIP crops to submit additional dietary Daphnia magna studies, or 

studies on the effects on an aquatic invertebrate representing a leaf shredder functional group in 

headwater streams. These data were to be submitted by January 31, 2012. 

Current Status:

Numerous recent peer-reviewed studies performed as a result of the Rosi-Marshall et al. 

publication identified several issues with the scientific merit and relevance to environmental 

risk assessment of the original study (Swan et al. 2009, Jensen et al. 2010, summarized by 

Beachy et al.2008, Parrott 2008, and Wolt and Peterson 2010). It appears that the adverse 

effects in the Rosi-Marshall laboratory study were not caused by toxicity of Cry1A, but were 

due to other differences between the plant test substances (Jensen et al. 2010). Field studies did 

not indicate any reduced abundance of Trichoptera in streams containing residues of Cry1A 

maize (Chambers et al. (2007). In addition, the data in Rosi-Marshall et al. (2007) corroborate a 

lack of risk to aquatic organisms in realistic environmental conditions, as presented in Chambers et 
Page 2 of 4 

al. (the authors of Chambers et al. are the same research group that produced the Rosi-Marshall et 

al. 2007 paper). Finally, post-harvest crop residue was identified as the most likely route of 

exposure (Carstens et al. 2010), however aquatic exposure to biotech crops has been shown to be 

limited temporally and spatially with low to negligible exposure concentrations of Cry proteins in 

post-harvest crop tissues (Swan et al. 2009, Griffiths et al. 2009, Jensen et al. 2010, Wolt and 

Peterson 2010, Carstens et al. 2010) Similar exposure characterization for pending biotech crops 

during the problem formulation stage, on a case-by-case basis, may likely indicate a lack of need for 

hazard testing to assess aquatic risks in many instances (ILSI-CERA 2009, Carstens et al. 2010). 

EPA Conclusion: 

The caddis fly matter is no longer an issue. Numerous peer-reviewed studies performed since 

the original publication claiming a possible environmental hazard, (as a result of Cry1A protein 

causing weight reduction to caddis flies in a laboratory study), show that the anticipated problem 

does not exist. The studies show a lack of toxicity and a lack of significant exposure in the 

environmental setting. Therefore the requirement for additional aquatic invertebrate studies to 

assess hazard to aquatic shredder species is waived for the existing Cry protein PIP registrations. 

II. ORIUS DATA REQUIREMENT 

Background: 

The August 2002 FIFRA SAP (EPA-SAP. November 6, 2002) recommended that EPA expand 

the non-target insect testing to include generalist predators such as the insidious flower bug 

Orius insidiosus (sometimes referred to as the minute pirate bug). As a result EPA required the 

registrants of expiring registrations to submit dietary studies with Orius insidiosus. These data were 

to be submitted by January 31, 2012. 

Current Status:

For commercialized crops containing insecticidal Cry proteins from Bacillus thuringiensis 

active against Lepidoptera and Coleoptera species, spectrum data indicate that toxicity is 

restricted only to insect larvae in these two Orders and biologically meaningful activity against 

Orius (a hemipteran insect) by anti lepidopteran and anti-coleopteran Cry ptoeins is low to nonexistent (Duan et al. 2006, Raybould et al. 2007). In addition, field data performed on 

commercialized events have not indicated adverse impacts on hemipteran pests within 

agronomic fields. (Sanvido et al.,2007, Marvier, et al., 2007). Consideration of such spectrum 

and field data would indicate a lack of need for further testing of with Orius or other hemipterans 

for existing Cry protein containing crops. Furthermore, commercial laboratories performing the 

testing encountered difficulties with rearing and maintaining acceptable control mortality levels 

in Orius tests (EPA MRID 474367-01. 2008). Also, at the present time there are no independent 

laboratories performing the assay. The Springborn Laboratories, an independent contract 

research organization and co-author on the Duan et al. (2007) paper, is no longer performing this 

assay. Therefore, ABSTC requests that requirements for Orius testing be suspended for currently 

registered Bt Cry protein crops. 
Page 3 of 4 

EPA Conclusion: 

The EPA has made a good faith effort to comply with the 2002 FIFRA SAP recommendation to 

expand non-target insect testing to include generalist predator species such as the minute pirate 

bug Orius insidiosus. The regulated industry responded at considerable expenditure of resources to 

comply with the requirement. However, due to lack of contract laboratories performing the testing, 

difficulty in obtaining and rearing of Orius, and repeated failure to maintain acceptable control 

mortality levels the testing has not been satisfactory. Therefore the requirement for additional

Orius studies to assess hazard to generalist predator species is waived for the existing Cry 

protein PIP registrations, and that testing of active ingredients other than Cry proteins be 

required only after development and validation of testing protocols. 

References 

Beachy, RN, NV Federoff, RB Goldberg, and A McHughen. 2008. The burden of proof: a 

response to Rosi-Marshall et al. Proc Natl Acad Sci USA 105: E9. 

Carstens, K.L., Anderson, J.A., Bachman, P., DeShrijver, A., Dively, G. Federici, B. Hamer, M., 

Gielkens, M., Jensen, P., Lamp, W., Raushen, S., Ridley, G., Romeis, J., Waggoner, A. 2010. 

Genetically Modified Crops and Aquatic Ecosystems: Considerations for Environmental Risk 

Assessment and Non-target Organism Testing. In preparation. 

Chambers, C., Whiles, M.R. Griffiths, N.A., Evans-White, M.A., Rosi-Marshall, E.J., Tank, J.L., 

and Royer, T.V. 2007. Assessing the impacts of transgenic Bt corn detritus on 

macroinvertebrate communities in agricultural streams. North American Benthological 

Society 55th 

Annual Meeting. June 7, 2007. Columbia, SC. 

http://nabs.confex.com/nabs/2007/techprogram/P1698.HTM 

Duan, J.J., Paradise, M.S., Lundgren, J.G., Bookout, J.T., Jiang, C., and Wiedenmann, 

 R.N. 2006. Assessing nontarget impacts of Bt corn resistant to corn rootworms: tier-1 testing 

 with larvae of Poecilus chalcites (Coleoptera: Carabidae). Environ. Entomol. 35:135-142. 

Duan, J.J., Huesing, J. Teixeira, D. 2007. Development of tier-I toxicity assays for Orius insidiosus 

(Heteroptera: Anthocoridae) for assessing the risk of plant-incorporated protectants to 

nontarget heteropterans. Environ. Entomol. 36(4):982-8. 

EPA-SAP. November 6, 2002. Corn rootworm plant-incorporated protectant insect resistance 

 management and non-target insect issues. Transmittal of meeting minutes of the FIFRA 

 Scientific Advisory Panel Meeting held August 27-29, 2002 at the Marriott Crystal City 

 Hotel, Arlington, VA. 

EPA. MRID 474367-01. 2008. Evaluation of Potential Dietary Effects of Cry34/35Ab1 Protein 

 on Insidious Flower Bugs, Orius insidiosus (Hemiptera: Anthocoridae), Study No. 

 13855.6105, Springborn Smithers Laboratories, 790 Main Street, Wareham, MA 02571-

 1037. 
Page 4 of 4 

ILSI-CERA (International Life Sciences Institute Research Foundation, Center for Environmental 

Risk Assessment). Problem Formulation of Biotech Crops and Aquatic Ecosystems. 1156 

15th 

Street, NW, Washington, DC 20005. October 13-15, 2009. 

Jensen, P.D., G.P. Dively, C.M. Swan, and W.O. Lamp. 2010. Exposure and non-target effects 

of transgenic Bt corn debris in streams. Environ. Entomol. 39(2):707-714. 

Marvier, M., C. McCreedy, J. Regetz, and P Kareiva. 2007. A Meta-Analysis of Effects of Bt 

 Cotton and Maize on Nontarget Invertebrates. Scince, Vol 316 8 June 2007, 1475-1477. 

Parrott, W. 2008. Study of Bt impact on caddisflies overstates its conclusions: Response to RosiMarshall et al. Proc. Natl. Acad. Sci. USA 105(7): E10. 

Raybould, A., Stacey, D., Vlachos, D., Graser, G., Li, X., and Joseph, R. 2007. Non-target organism 

risk assessment of MIR604 maize expressing mCry3A for control of corn rootworm. J. Appl. 

Entomol. 131(6): 391-399. 

Rosi-Marshall, E.J., Tank, J.L., Royer, T.V., Whiles, M.R., Evans-White, M., Chambers, C., 

Griffiths, N.A., Pokelsek, J., and Stephen, M.L. 2007. Toxins in transgenic crop byproducts 

may affect headwater stream ecosystems. Proc. Natl. Acad. Sci. USA 104:16204–16208. 

Sanvido,O., Romeis, J., Bigler, F. 2007. Ecological Impacts of Genetically Modified Crops: Ten 

Years of Field Research and Commercial Cultivation. Adv Biochem Engin/Biotechnol 

107: 235–278 

Swan, C.M., P.D. Jensen, G.P. Dively, and W.O. Lamp. 2009. Processing of transgenic crop 

residues in stream ecosystems. J. App. Ecol. 46:1304-1313. 

Wolt, J.D. and Peterson, R.K.D. 2010. Prospective formulation of environmental risk 

assessments: Probabilistic screening for Cry1A(b) maize risk to aquatic insects. 

Ecotoxicol. Environ. Saf. Epub.