Scientists block insects' sense of smell to protect crops


September 27, 2009

Scientists are hoping that by confusing insects' sense of smell, they won't be able to locate crops (Photo: Noel McKeegan)

Scientists are hoping that by confusing insects' sense of smell, they won't be able to locate crops (Photo: Noel McKeegan)

Good news for crop farmers this week with UK scientists discovering molecules they hope will confuse insects’ sense of smell and therefore their ability to detect plants – and each other. The researchers believe this could reduce the damage insects cause to crops and lead to better food security. Roughly one-quarter of the world’s crops are lost annually to pests and disease.

Lead researcher Dr Antony Hooper of Rothamsted Research, an institute of the Biotechnology and Biological Sciences Research Council (BBSRC) which funded the research, said: “One way in which insects find each other and their hosts is by smell, or more accurately: the detection of chemical signals – pheromones. Insects smell chemicals with their antennae; the chemical actually gets into the antennae of the insect and then attaches to a protein called an odorant-binding protein, or OBP. This then leads to the insect changing its behavior in some way in response to the smell, for example, flying towards a plant or congregating with other insects.”

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

“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,” Dr Hooper said. “We could potentially apply these compounds, or similar ones, in some way to block the insects’ 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.

“There is a lot of work to do from this point. We want to test this idea with important crop pests – we’ll probably start with aphids because they are a serious pest and we have some idea of what the aphid OBPs are like from the genome sequence. We’d also hope to apply our knowledge to insects such as tsetse flies and mosquitoes that carry human diseases. And ultimately we’ll look at developing ways to design suitable compounds to control these pests.”

“Around a quarter of crops are lost to pests and diseases and so if we are to have enough food in the future it is not just a matter of increasing gross yield, said Prof Douglas Kell, BBSRC Chief Executive. "To secure our future food supply we must look for new and innovative ways to prevent and control pests and diseases. This is an interesting finding that could be applied across a number of important insect pests and may have far reaching implications for preventing human disease as well.”

The team’s findings were published this week in Chemical Communication.


The OBP or odorant binding protein / PBP or pheromone binding protein is the receptor. It releases sequestered ions on contact with pheromone to excite an EPSP. See: Nicholson B., Pheromones cause disease: pheromone/odourant transduction. Med Hypotheses. 2001 Sep;57(3):361-77. Nicholson B., Pheromones cause disease: the exocrinology of anorexia nervosa. Med Hypotheses. 2000 Mar;54(3):438-43. Nicholson B., Does kissing aid human bonding by semiochemical addiction? Br J Dermatol. 1984 Nov;111(5):623-7. Nicholson B., Pheromones cause disease: the electrodeposition mechanism of atherosclerosis. In press.


Of course, the praying mantis in the picture is one of the myriad of helpful insects that could get unintentionally harmed by this project, including honeybees required for pollination, and other insects required to help with the decomposition cycle.

If the OBP can be specifically genetically engineered to be specie specific, the protect the good species from interference, then this is a worthwhile project.

/R Dr. Rings


Correct me if I'm wrong, but isn't the praying mantis a carnivorous predator, making it inappropriate to illustrate this article? In fact, they eat pests.


A great innovation.

Some traditional methods used in South India are worth probing scientifically. In the Groundnut (peanut) crop RED HAIRY CATER PILLAR is a menace. It eats away the leaves. It comes out in the night and hides in daytime by digging a hole. Rural farmers put CALOTROPIS leaves in the field here and there. After eating the calotropis leaves further regeneration is arrested. Perhaps the latex in the leaves is responsible. If scientists study this phenomenon and synthesise the pigment responsible, that will be a major breakthrough in crop protection.

Also while sowing the peanut CROWS are a big menace. They eat away the seeds. Rural people put latex from EUPHORBIA ANTIQUORUM in cooked rice and place it on trees. The crows eating the rice die. They bring one dead crow and tie it in the middle of the field on a stick. The crows will be flying around the dead crow but won\'t descend.

If the active ingredient in the latex of Euphorbia Antiquorum is isolated and synthesised, it may lead to synthetic rodenticide.

Dr.A.Jagadeesh Nellore (AP), India

Anumakonda Jagadeesh
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