Bt Brinjal The scope and adequacy of the GEAC environmental risk assessment

Environmental Risk Assessment 33clear what inferences about environmental safety were intended to be drawn from the studies. Second, the Dossier did notcontain any of the experimental details for these studies, so it was not possible to assess independently the reliability of thesummarised results.Third, these laboratory studies used native Cry1Ac toxin, not the chimeric Ccry1A toxin that is found in Bt brinjal. Thereis no need to use native Cry1Ac when Ccry1A could be produced in heterologous systems (See transgene characterisationchapter). EC-II (page 78) states that “the [native Cry1Ac] protein … has been demonstrated to be biochemically and functionallysimilar to the one produced in Bt brinjal event EE-1 through a series of tests.” Biochemically, the native Cry1Ac is not identicalto Ccry1A in Bt brinjal, because it is recognised as different (EC-II, page 66). None of the functional tests are described andnone of the data are provided in EC-II or the Dossier, so the claim cannot be evaluated. At the bare minimum, these functionaltests should demonstrate similar uptake, metabolism and degradation in vivo under relevant environmental conditions, whichare the minimum standards for proving functional similarity for generic drugs. In addition, similarity should be assessed usingstatistical equivalence tests. Functional tests should also include competitive equilibrium and non-equilibrium binding studiesto brush-border membrane vesicles with Cry1Ac, Cry1Ab, or Cry1Aa receptors, competitive absorption and release studies onsubstrates such as clay minerals and fractionation columns, and proteinase digestion studies examining the rate of degradationand the rate of end-product formation for several different proteinases found in insects and other species.It is essential to identify appropriate indicator species that occur in Indian brinjal fields and correspond to one or moreof the kinds of possible adverse effects (A-F above) that need to be assessed, and then to assess impacts on these species inecologically relevant ways. One approach is provided by Hilbeck et al. (2008).Finding 15. EC-II examines the risk of potential non target pests, but overstates conclusions based on limited andhighly variable data. The limited field trial data suggest that phytophagous mites will not become secondary pests of Btbrinjal, but the data are insufficient to draw conclusions about whether the other important non-target pests will or willnot become secondary pests.The most useful non-target data used in the EC-II assessment is from the series of limited field trials conducted at 19 sites(Multi-site trials, Dossier, volume 6). These studies address potential adverse effect (A) increased secondary pests, either throughdirect enhancement or through the reduction of natural enemy controls. This risk is one of the most important to considerfor brinjal producers, because a secondary pest outbreak on Bt brinjal could cause crop failure, excessive debt, and loss oflivelihood, or increased insecticide or miticide use. For example, mealy bugs have become a serious pest of Bt cotton in India.While it is not clear that the cause is related to the Bt transgene or to the genetic background of the Bt cotton varieties, this hashad serious detrimental consequences to farmers.Based on examination of the results reported in the Dossier (volume 6), the following species and groups of species hadsufficient data to interpret: aphids (primarily Aphis gossypii), leafhoppers (primarily Amrasca devastans), thrips (Thrips sp.and Frankliniella schultzii), white fly (primarily Bemisia tabaci), and mites (Tetranychus spp.). All other species reported haveinsufficient data to make a sound conclusion about secondary pest status. The five species are probably the most importantarthropod pests of brinjal. The first four of these (aphids, leafhoppers, thrips and white fly) typically have high inter-annualvariation in population density. Because this variation makes it more difficult to detect population trends over a short periodof time, a few more years of study will be necessary before reliable inference can be made about secondary pest status of theseinsects. Mites, however, typically have more uniform population densities from year to year. Consequently, the results from thelimited field trials suggest that mites will not be significant secondary pests in Bt brinjal.There are several important diseases of brinjal that should also be evaluated, including little leaf wilt and Fusarium wilt.However, the disease data are too sparse to draw any meaningful inferences. There was one observation of an increasedfrequency of little leaf wilt on Bt brinjal at Coimbatore during 2005 that might indicate future troubles and would meritadditional study.Root-knot nematodes (Meloidogyne spp.) are serious pests of brinjal in many areas in India. These were not considered inEC-II, the Dossier, or the Supplemental Materials. If these pests became more severe on Bt brinjal, it would have significantnegative consequences on brinjal farmers.