Cornell University’s plans to release genetically modified (GM) moths in New York State ignore existing evidence of failure, which shows the GM pests will damage the broccoli and cabbages they are supposed to protect, GeneWatch UK stated Monday.

Diamondback moth caterpillars are agricultural pests which eat brassica crops including cabbages and broccoli. Cornell plans multiple experimental releases of up to 30,000 GM male moths a week, over a two year period, at its New York State Agricultural Experiment Station (NYSAES). The GM diamondback moths are produced by UK-headquartered company Oxitec, which was bought by Intrexon, Inc. for $160 million in 2015, despite its lack of revenue and commercial products.

Oxitec claims its technology builds on the “Sterile Insect Technique”, in which sterile pests are released to mate with wild ones and suppress the population. However, Oxitec’s GM male moths are not sterile, they mate and reproduce. The female offspring of these matings do not die until the larval stage, with male offspring surviving until adulthood. This means that GM caterpillars will contaminate crops where the GM males are released and cause significant damage to the crop that would not occur if the released insects were sterile.

The only scientific paper published on the effects of releasing these GM moths shows that even in greenhouse experiments (which are much more effective than open releases), releases needed to continue for ten weeks to suppress a target moth population, during which crop damage would occur (1). In the reported experiments, GM males were released in ratios of between 10 and 40 GM males to one wild male, to suppress the population. In further experiments including broccoli plants, the paper reports that “Plants were replaced after 4 weeks, or when defoliated due to larval feeding, by cutting them at their base and placing them on the replacement plants to allow larvae to transfer”.