Rothamsted: Sending insects off the scent of crops

Research lead

Scientists funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC) have discovered molecules that could compromise an insect’s ability to detect crop plants by interfering with its sense of smell. This could form the basis of a new pest control.

Lead researcher Antony Hooper of Rothamsted Research, a BBSRC institute, said, “One way in which insects find each other and their hosts is by smell, or more accurately: the detection of chemical signals – pheromones, for example.” Insects smell these chemicals when they enter their antennae and attach to a protein called an odorant-binding protein, or OBP.

“This then leads to the insect changing its behaviour in some way in response to the smell, for example, flying towards a plant or congregating with other insects,” said Hooper.

Studying an OBP found in the silkworm moth Bombyx mori, Hooper and his team were able to look at how the OBP and a relevant pheromone interact. They also tested the interaction between OBP and other molecules that are similar to, but not the same as, the pheromone.

Hooper continued, “As well as learning about the nature of this interaction we've actually found that there are other compounds that bind to the OBP much more strongly than the pheromone. We could potentially apply these compounds, or similar ones, in some way to block an insect‚s ability to detect chemical signals – the smell would be overwhelmed by the one we introduce. We‚d expect the insects to be less likely to orientate themselves towards the crop plants, or find mates in this case, and therefore could reduce the damage.

The researchers now plan to rest the idea with important crop pests, starting with the aphid, which is the most economically significant insect pest. The genome sequence of the aphid has been completed recently, providing insights into the structure of its OBPs.

“We’d also hope to apply our knowledge to insects such as tsetse flies and mosquitoes that carry human diseases,” said Hooper.