GM Insects

Insects are genetically modified by altering or inserting new genes into their DNA, causing the transgenic insect to eventually be unable to reproduce and eventually die. Population suppression is achieved by use of a self-limiting gene which is passed on to offspring to reduce population numbers. Transgenic males are released and mate with wild females. Offspring produce no or very few offspring that survive to reproductive adulthood.

The self-limiting gene produces a protein called tetracycline controlled TransActivator (tTAV).  In the absence of the antibiotic tetracycline, tTAV proteins are produced and insects die before they reach reproductive maturity, usually at the larval stage. Large transgenic insect populations are reared to maturity for release by adding tetracycline antibiotic to their diet. Transgenic insects are made by injecting the tTAV gene into insect eggs, although new gene editing techniques will replace this approach. Transgenic insects have fluorescent marker genes to be able to identify and monitor all developmental in the field environment. This track and trace ability allows understanding of insect populations, control efficacy and planning of subsequent new transgenic male insect population release as required. Another potential approach is to permanently replace wild insect populations with transgenic ones unable to disease-causing agents, known as a “gene drive”.

Benefits include precision control of specific crop damaging insect species and reduced chemical pesticide application and its associated problems with insect resistance.  The technology, already in use in the USA, is claimed to be self-limiting in the field and can either be used a stand-alone solution or as part of an IPM approach.