This policy brief, published by the UK Parliamentary Office of Science and Technology (POST), examines the potential of genetically modified (GM) insects in controlling insect-borne diseases and agricultural insect pests.

Insect-borne diseases pose significant health risks to approximately half the world's population — malaria alone kills nearly one million people each year.

Insects also damage livestock and crops. A single insect pest of maize can cause economic losses of up to US$60 million in some African countries.

Control strategies have traditionally focused on the use of chemical insecticides or the Sterile Insect Technique (SIT) where laboratory-reared male insects, sterilised by radiation, are released to mate with wild females in a form of area-wide birth control.

But new methods to manipulate genes, developed over the past decade, offer an alternative strategy: the use of GM insects. These can be used to control insect pests through population suppression or population replacement.

Suppression builds on the SIT, where insects are engineered to contain a 'lethal gene' that ensures they have no viable offspring.

And replacement strategies, also known as 'gene drive' methods, involve permanently replacing wild insect populations with GM varieties altered to make them less able to transmit disease.

Both strategies could complement existing efforts but also provide several unique benefits. They target single insect pest species, work in inaccessible populations, and protect everyone in the release area regardless of socio-economic status.

But their use is controversial. They are near impossible to monitor and are irreversible. Little is known about their potential long-term effects — for example, whether new genes would 'jump' into other species.

Regulation is also a concern. Where national biosafety regulations exist, they — like the international Cartagena Protocol on Biosafety — tend to focus on GM crops. The lack of appropriate guidance on how to regulate GM insects may slow down the development of these technologies.

Link to full policy brief from POST