Petition 07-253-01p: Syngenta's Insect-Resistant MIR162 Corn 


Response to Comments 


The Animal and Plant Health Inspection Service (APHIS) ofthe United States 

Department of Agriculture (USDA) reviewed a Syngenta petition (APHIS No. 07-253­

01 p) requesting a determination ofnonregulated status for their genetically engineered 

(GE) insect-resistant com cultivar MIR162. Syngenta submitted data supporting their 

petition that MIR162 com should no longer be considered a regulated article under 

APHIS Biotechnology Regulations (7 Code ofFederal Regulations (CFR) part 340) 

because MIR162 com is unlikely to pose a plant pest risk. Prior to reaching a 

determination, APHIS prepared a plant pest risk assessment (PPRA) to evaluate whether 

MIR162 com is likely to pose a plant pest risk. Based on the plant pest risk assessment, 

APHIS concluded that MIR162 com is unlikely to pose a plant pest risk and is therefore 

eligible for nonregulated status. APHIS also prepared a draft environmental assessment 

(EA) to evaluate whether there could be significant impacts on the environment arising 

from a decision to grant a determination ofnonregulated status to MIR162 com. APHIS 

prepared the EA as part ofits obligation to meet the statutory requirements of the 

National Environmental Policy Act (NEPA) of 1969 (42 U.S.c.A. § 4321 et seq.). As 

part of this process, APHIS considered public comments received on the petition for a 

determination of nonregulated status and associated draft EA. This document provides 

APHIS' response to these comments. 

On January 13,2010, APHIS published a notice in the Federal Register (75 FR 1749­

1751, Docket No. APHIS-2009-0072) announcing the availability ofthe Syngenta 

petition and the APHIS PPRA and EA for a 60-day public review and comment period. 

This comment period ended on March 15,2010. APHIS received a total of 35 comments 

from various groups and individuals. Nineteen comments supported deregulation, while 

16 comments generally opposed the development and use of genetically engineered 

foods. 

Those supporting a determination of nonregulated status included six academicians, six 

individuals from the com industry, four com trade groups, and three com growers. Those 

opposing a determination of nonregulated status included a com grower, two Non 

Governmental Organizations (NGOs) (supplied four comments), and 11 individual 

consumers. 

Supporters of a determination of nonregulated status for MIR162 cited a number of 

benefits they personally observed from growing either MIR162 com test plots or other 

insect-resistant Bt com, or because oftheir experience dealing with the GE insectresistant com. A few salient observations that provide supporting evidence for MIR162 

com are: (1) It was found effective against a broad spectrum of difficult to control 

lepidopteran pests such as com earworm, fall armyworm, western bean cutworm, black 

cutworm, and sugarcane borer; (2) It would be a useful tool in a lepidopteran insect 

control strategy within com Integrated Pest Management (IPM) programs; (3) It reduced 

foliar chemical spray by controlling a broad spectrum oflepidopteran pests; (4) It 

potentially delays lepidopteran insect resistance because it has a different mode of action 
than other Bt com; (5) It reduced aflatoxin contamination of com grain; (6) It has a 

potential to provide greater economic benefits to com growers through reduced 

lepidopteran pest damaged grain loss and/or reduced foliar insect spray; and (7) Any such 

reduction in use of chemical insecticides potentially enhances environmental benefits. 

A majority ofthose opposed to a determination ofnonregulated status did not mention 

their specific disagreement with APHIS' analyses detailed in the EA (USDA-APHIS 

2010) or the PPRA (USDA-APHIS 2009); rather they expressed their general opposition 

to genetically modified crops. One com grower commented that, contrary to his 

expectation, the use of pesticides increased on his farm when he used GM seeds. 

Likewise, two individuals expressed their belief that GE com pollen endangers all 

honeybees and other insects in the com agroecosystem. Two individuals expressed their 

concern about genetic contamination of conventional com from GE com and food and 

feed safety ofGE com. One person specifically mentioned that there is plenty of 

scientific evidence that GMOs (= GE) are the root cause of many diseases. People who 

expressed their opposition to deregulation did not provide any supporting evidence for 

their claims. In the following paragraphs APHIS reiterates its findings to address the four 

major concerns expressed by individuals. 

1. Pesticide use on Insect Resistant GE Corn Crop 

A com grower who opposed granting nonregulated status to MIR162 com contends that 

introduction ofGE crop varieties has led to increased pesticide use rather than decrease 

as the providers ofGM seed would lead one to believe. Because of this disparity in 

pesticide usage claim on GM corn, the commenter believes that APHIS should not grant 

nonregulated status to MIR162 com until sufficient data are generated to show that plant 

incorporated protectants, such as Cry and Vip proteins, act as true pesticides. 

APHIS disagrees with the commenter's assertion. As summarized in the EA (B7­

Agricultural Benefits, p. 28), adoption ofGE crops is associated with reduced pesticide 

use. Insecticide use on fields planted to Bt corn has decreased substantially since 

introduction ofBt corn in the mid 1 990s (Figure 1 in EA; also see figure 8 in FernandezCornejo and Caswell 2006) and use rates (in terms of active ingredient) on corn has 

declined since the introduction ofGE corn in 1996. Using 2001 data, USDA-ERS found 

that insecticide use was 8 percent lower per planted acre for adopters ofBt corn than for 

nonadopters (Fernandez-Cornejo and Li 2005). The USDA-ERS results generally agree 

with field-test and other farm surveys that have examined the effects of using GE crops 

(Table 1 in EA). The MIR162 corn and stacked hybrids may further reduce insecticide 

use ifthe current trend in insecticide usage continues (Figure 8 in Fernandez-Cornejo and 

Caswell 2006). 

As discussed in the EA (III. Introduction, p. 7) and petition (LB. Rationale for 

Development ofMIR162 Maize, pp. 11-13), currently available insect-resistant Bt crops 

are highly effective against European corn borer (Ostrinia nubilalis) and southern and 

western com rootworm species (Diabrotica spp). But com is susceptible to attack by a 

variety of insects (Table 1, pg. 12 in petition) from the time it is planted until it is 

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consumed as food or feed. Current Bt com cultivars provide only limited protection 

against feeding damage caused by com earworm (Helicoverpa zea), fall armyworm 

(Spodopterafrugiperda), black cutworm (Agrotis ipsilon), and western bean cutworm 

(Striacosta albicosta). Syngenta developed MIR162 to provide resistance to those latter 

com insect pests. Moreover, when MIR162 com traits are combined with previously 

deregulated Bt traits in one or more cultivars, such cultivars would be expected to 

provide a wide range ofprotection against a variety of insect pests, further reducing 

insecticide use in the future (Fernandez-Cornejo and Caswell 2006). 

2. Impact of MIR162 Corn on Honeybees and Other Beneficial Insects 

An NGO commented that pesticides harm honey bees, therefore, GE pesticides similar to 

the one present in MIR162 com are going to endanger honey bee populations if such com 

varieties are granted nonregulated status. 

APHIS' analyses on impact ofthe introduced gene product in MIR 162 com are presented 

in the EA (B-5. Potential Impact on Non-target Organisms, Including Beneficial 

Organisms and Threatened or Endangered Species, pp. 22-25) and data are provided in 

the petition (VII.C.3. Expected Environmental Concentrations for Nontarget Organisms, 

pp. 78-83; Impact on Nontarget Organisms, pp. 84-89; for honey bee data please see the 

sections VII.C.3.c. EEC for Pollinators, p. 80 and VII.D.3. Effect ofVip3Aa on 

Pollinators). 

The Vip3Aa20 protein is selectively toxic to a few species ofinsect pests belonging to 

the order Lepidoptera. Non-Lepidopteran insect species are not expected to be affected 

by theVip3Aa20 protein. Its receptor-mediated mechanism of action and the absence of 

activity in bioassays with multiple species outside ofthe order Lepidoptera support this 

conclusion. Furthermore, Syngenta observed no harmful effects ofVip3Aa proteins on 

representative non-target organisms that are associated with com agroecosystems or in 

their hazard identification studies that used a wide range oftaxa at expected 

environmental concentrations (Table 31, pg. 89 of petition). In the honey bee (Apis 

mellifera) study conducted by Syngenta, there were no observable adverse effects or 

differences in survival noted at doses ofVip3A proteins that were well above those 

expected from exposure to the Vip3Aa20 protein from MIR162 com planted in the field 

(petition Table 30, p. 84 and Table 31, pg. 89). According to the Environmental 

Protection Agency's Biopesticides Registration Document on Vip3Aa20 Maize (EPA 

2009) there are enough empirical data from peer-reviewed publications providing support 

that Bt crops have not caused any adverse effects on nontarget organisms, including 

honeybees. 

3. Genetically Engineered Corn Contaminates Conventional Corn Cultivars 

through Gene Flow 

Two NGOs oppose granting nonregulated status to MIR162 com because gene flow from 

GE com varieties is going to contaminate conventional com cultivars threatening their 

survival. 

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Available data on com gene flow and APHIS' assessment of the petition data do not 

support this assertion. Gene flow is a natural biological process with significant 

evolutionary importance. A number of flowering plants are the product ofgene flow and 

introgression (Grant 1981; Soltis and Soltis 1993; Rieseberg 1997), and even in the 

existing floras, the occurrence of hybridization or introgression is reported to be 

widespread (Knobloch 1972; Stace 1987; Rieseberg and Wendel 1993; Peterson et al. 

2002). Gene flow between crop cultivars is also very common (Ell strand et aI. 1999; 

Stewart et al. 2003). ). It has been a common practice by plant breeders to artificially 

introgress traits from wild relatives into crop plants to develop new cultivars. Traditional 

com, landrace com, or elite non-GE com are all ultimately derived from their ancestral 

parental species teosinte through human selection (White and Doebley 1998; Doebley 

2004). Furthermore, a few important genes, such as dwarfing genes in wheat and rice, 

(Hedden 2003) and the teosinte branching gene in com (Doebley et aI. 1995), have 

transformed agriculture across the globe. Thus, the end product of genetic engineering 

techniques is not different from what has been practiced through conventional breeding 

techniques. Also, the food, feed and environmental safety ofthe introduced genes, 

obtained either via conventional breeding or GE, solely depends on the nature of the gene 

products. A body of scientific evidence shows that gene flow per se does not contaminate 

plant populations, rather it can increase or decrease genetic diversity of plant populations. 

APHIS recognizes that com is open-pollinating and it is possible that the engineered 

genes could move via wind-blown pollen to an adjacent field. All com, whether 

genetically engineered or not, can transfer pollen to nearby cornfields. However, an 

influx of pollen originating from a given com variety may not appreciably change the 

characteristics of com in adjacent fields because gene flow declines rapidly with 

increased distances from a pollen source popUlation (Halsey et aI. 2005). Other factors 

such as wind speed, host variety and temperature also affect pollen flow (Aylor et aI., 

2003; Jones and Brooks, 1950). For example, in a study assessing observations of a large 

number of commercial canola fields, the incidence of gene flow was on the order of 

0.015 % at 500m (see Fig 2 in Rieger, 2002). In a smaller com research study, the 

incidence of gene flow was 0.05% at 100m (Goggia et aI., 2006). Methods of spatial and 

temporal isolation are widely used and accepted when seed producers are seeking to 

minimize the influx of pollen from sources outside a seed production field. These 

methods are readily applicable to the production of certified organic com seed. To 

maintain varietal purity, AOSCA (Association ofOfficial Seed Certifying Agencies) 

recommends 200 meters isolation from nearby com popUlations to produce the 

foundation class of certified seed (AOSCA 2003). 

There are many practices non-GE com producers use to prevent movement of GE com or 

the pollen from GE com into their production fields (Bradford 2006; Schienmann 2003; 

Ziegler 2000). Growers may chose to plant earlier or later than neighboring farmers who 

may be using GE crops, ensuring that the flowering times between GE and non-GE 

produced crops will differ, thus minimizing the chance of pollen movement between 

fields. They may also employ adequate isolation distances between different com crops 

field to minimize the chance that pollen will be carried between the fields. 

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When Syngenta receives regulatory approval from APHIS, it will likely make MIR162 

corn available to growers and breeders. It is not likely that buyers and sellers who 

choose not to plant or sell MIR162 corn or other transgenic corn varieties will be 

significantly impacted by the expected commercial use ofthis product because: (a) nontransgenic corn varieties will likely still be sold and will be readily available to those who 

wish to plant them; (b) Syngenta's stewardship plan will provide farmers that purchase 

MIR162 corn with recommended management practices for MIR162 corn cultivation; (c) 

methods of spatial and temporal isolation are widely used and accepted and corn seed 

producers employing them can minimize the influx of pollen from sources outside the 

seed production field; (d) 85% ofthe 2008 corn acreage in the United States is already 

planted to transgenic herbicide tolerant and/or insect resistant varieties; and (e) APHIS 

expects that MIR162 may replace some ofthe presently available GE corn varieties 

without significantly affecting the overall total corn acreage. APHIS concludes that 

farmers who cultivate non-GE corn crops will be able to coexist with GE corn producers 

as they do now. 

4. Food and Feed Safety ofMIR162 Corn for Humans and Animals 

Two NGOs expressed concerns that the long-term consequences of GE food are not fully 

understood and there is plenty of scientific evidence that GE food is the root cause of 

many diseases. 

APHIS disagrees with commenter's' statements. As summarized in the EA (Human and 

Environmental Benefits, p. 32) there were no human health concerns observed with 

respect to toxicity or allergenicity ofthe proteins expressed in MIR162 corn. In a variety 

offield studies, other insect protected corn expressing Bt proteins have been shown to 

have significantly lower levels of common mycotoxins that are produced by fungal 

pathogens (Wu 2006). 

A comprehensive safety assessment ofthe Vip3Aa20 and PMI (Phosphomannose 

isomerase) proteins demonstrated that both proteins are nontoxic to mammalian species 

and are unlikely to be food allergens (69 FR 26770-26775; 73 FR 45620-45624; FDA 

BNF No. 000113). The Vip3Aa20 protein is considered nontoxic because it does not 

share significant amino acid homology with known protein toxins, is non-toxic to mice at 

a very high dose, is rapidly degraded in simulated mammalian gastric fluid, and its 

insecticidal mode of action for Vip3Aa20 is not relevant to mammals. 

Vip3Aa20 is also not likely to be a food allergen because it is not derived from a known 

source of allergenic proteins, it does not have significant amino acid sequence identity to 

known allergenic proteins, it is rapidly degraded in simulated mammalian gastric fluid, 

and it is labile upon heating at temperatures of 65°C and above. On August 6, 2008, EPA 

granted an exemption from the requirement of a tolerance for residues ofB. thuringiensis 

Vip3Aa proteins (including the Vip3Aa20 variant) in or on food and feed commodities of 

corn (73 FR 45620-45624). 

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PMI is considered nontoxic because it does not share significant amino acid homology 

with known protein toxins, it is nontoxic to mice at a very high dose, and it is rapidly 

degraded in simulated mammalian gastric fluid. PMI is not likely to be a food allergen 

because it is not derived from a known source of allergenic proteins, it does not have 

significant amino acid sequence identity to known allergenic proteins with implications 

for its allergenic potential, it is rapidly degraded in simulated mammalian gastric fluid, 

and it is labile upon heating at temperatures of 37°C and above. A permanent exemption 

from the requirement of a food tolerance currently exists under 73 FR 45620-4562440 for 

Vip3Aa20 in maize and under 40 CFR § 180.1252 for PMI in all plants. 

As presented in Appendix II ofthe EA (p. 50), the compositional analyses of corn grain 

revealed no statistically significant differences between MIR162 and control means for 

43 of the 56 analytes including carbohydrates, proteins, fats, minerals and vitamins. 

Collectively, even for those few analytes that showed some difference, the observed 

differences between MIR162 and control means are considered of no biological 

significance and represent typical random variance. The magnitude of the differences 

was small (all MIR162 values fell within normal ranges for conventional maize) and the 

MIR162 and control data ranges significantly overlapped. MIR162 is therefore, not 

compositionally different from conventional maize. 

A food and feed nutritional and safety assessment ofMIR162 corn has been completed 

by the FDA. Under Federal Food, Drug, and Cosmetic Act (FFDCA), it is the 

responsibility of food and feed manufacturers to ensure that the products they market are 

safe and properly labeled. Food and feed derived from MIR162 corn must be in 

compliance with all applicable legal and regulatory requirements. FDA completed their 

consultation on MIR162 on December 9,2008 and concluded that it had "no further 

questions concerning grain and forage derived from corn event MIRI62" (FDA BNF No. 

000113). 

According to the Society ofToxicology position paper on the safety ofgenetically 

modified foods produced through biotechnology (Hollingworth et al. 2003), the available 

scientific evidence indicates that the potential adverse health effects arising from 

biotechnology-derived foods are not different in nature from those created by 

conventional breeding practices for plant, animal, or microbial enhancement, and are 

already familiar to toxicologists. The authors contend that it is therefore important to 

recognize that the food product itself, rather than the process through which it is made, 

should be the focus of attention in assessing safety. 

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