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