GeneWatch UK Briefing: Oxitec's genetically modified moths: summary of concerns

November 2015

The UK-based company Oxitec is seeking to release genetically modified (GM) moths (also known as GE moths) into open fields in New York State. This briefing summarises the concerns about the proposed releases of the diamondback moths, a pest which eats broccoli and cabbages.

Download the briefing here.

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Problems identified with Oxitec's approach include:

(i)         The use of late-acting lethality (rather than sterility) - which means the moths will mate and produce viable offspring, the females of which die mostly at the larval stage. This means that food supplies for humans and animals are likely to become contaminated with dead female GM caterpillars;

(ii)        Lack of adequate safety testing to demonstrate that consuming dead GM female caterpillars in crops will be safe for humans, birds or animals, including threatened species. Adult insects could also be swallowed during mass releases;

(iii)       In addition, the use of tetracycline to breed the GM Diamondback moths in the lab may facilitate the spread of antibiotic resistance via gut bacteria or discharges from the GM insect breeding facility;

(iv)       Oxitec's approach is not compatible with conventional or organic controls for other pests. Impacts of the single-species approach on other pests may include increases in the numbers of such pests or establishment in new areas: this may include invasive pests;

(v)        The use of a female-killing approach, in which only the female GM larvae die, is likely to lead to the dispersal of GM males to neighbouring crops or weeds, where they may survive and breed for multiple generations. Male GM moths may spread over significant distances in the longer term, via migration, or if contaminated crops enter the food chain. Surviving females may also be dispersed and the numbers of female survivors may increase as resistance develops or if the GM moths breed in areas contaminated with the antibiotic tetracycline;

(vi)       The use of a strain of diamondback moth which is not indigenous to the area poses further risks, as does the proposed release of non-GM wild diamondback moths, some of which may be expected to disperse and persist in the environment;

(vii)      The presence of contamination with dead GM caterpillars in a crop is not compatible with organic production systems and could put organic certification at risk. Contamination would also likely damage markets for both organic and conventional crops, including export markets, many of which require safety testing and labelling of GMOs. It is unclear who would be liable for the loss of markets in the event of such contamination.

The briefing concludes that open releases of GM diamondback moths are premature because of the serious limitations of this technology, lack of information needed to assess the risks, and inadequate regulation.

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