Scientists Conducting Tests of Genetically Altered Diamondback Moths

Posted on July 19, 2015

Scientists are studying a genetically altered diamondback moth. Diamondback moths (Plutella xylostella) are considered the worst insect pest of brassica crops, which include crops like cabbage, broccoli, kale and cauliflower. The tiny insect costs farmers up to $5 billion worldwide. Researchers believe a moth with a self-limiting gene can help reduce this damage.

A company named Oxitec, spun out from Oxford University, has developed a genetically engineered diamondback moth called the Oxitec Diamondback Moth (OX4319L) or Oxitec DBM. Oxitec DBM will be released to mate with regular female diamondback moths. A self-limiting gene will be passed on that prevents all female offspring from reaching adulthood. The idea is that this will then reduce the number of reproductive females in the diamondback moth population and cause the overall number of moths to dwindle over time.

The approach was inspired by the Sterile Insect Technique (SIT) where male insects are sterilized by radiation and released to mate with pest females. Oxitech uses a self-limiting gene carried by the male insects instead of sterilization through radiation. Oxitech says the self-limiting gene is non-toxic, so the moths can be eaten by birds or other animals with no adverse effects. The Oxitec moths also carry a color marker for monitoring.

Oxitech says research conducted in greenhouses found that diamondback moth populations within the greenhouses were well controlled within 8 weeks. A research paper on the test results can be found here in the journal, BMC Biology.

BBC News reports that new small-scale field release studies of Oxitech DBM has been approved by the US Department of Agriculture (USDA). The studies will be conduct outdoors under netting at Cornell University this summer. Cornell has a FAQ about these contained field cage trials here.

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