Research by Diamond Light Source could have a significant impact on the development and refinement of eco-friendly pest control methods for worldwide agriculture.
The importance of understanding how insects 'smell' and how the chemical signals are recognised is useful for many things, but especially for pest control in agriculture.
Determining the composition and processes behind the olfactory functions of insects feeds directly into the development and refinement of new pathways to influence insect host locating behaviours.
Plants use chemical signals to repel and attract insects and by harnessing a detailed understanding of the signals, farmers can plant companion species to create 'odours' that would make an area unattractive or attractive to insects according to what they require.
This is more commonly known as the push-pull system.
Published in the 'Journal of Molecular Biology', the study was carried out by Dr Jing-Jiang Zhou and colleagues at Rothamsted Research, in collaboration with Prof Nick Keep's group from the Institute of Structural and Molecular Biology at Birkbeck, University of London.
Zhou, senior research scientist in insect molecular biology at Rothamsted Research, studies insect olfaction and chemical ecology at the molecular level.
He said: 'Using Diamond Light Source's intense X-rays, we unravelled the detailed mechanisms linked to pheromone detection which dictates mating behaviour in silkworm moths.
'They are a model organism and any new insights into the working of their olfactory system have repercussions on our global understanding of how insects locate mates and their hosts.'
Solving this protein structure also represents a significant achievement in the advance of structural biology in the UK and it marks the 100th structure identified at Diamond since its opening in 2007.
Many insects depend on chemicals such as pheromones to communicate with each other and to find a suitable mate.
There are two main sex-pheromone components - bombykol and bombykal - in the silkworm moth.
Bombykol, the first insect pheromone discovered 50 years ago, is the only component involved in mating behaviour whereas bombykal is an antagonist.
Zhou added: 'So far, we know that odorant binding proteins (OBPs) within the organism pick up pheromones at pores on the outside of the antenna and carry them through a watery layer to the nerve endings.
'But it is not clear whether they simply transport and release molecules which bind to olfactory receptors or whether they form a specific OBP- pheromone complex which then activates the receptor.
'The structures we determined using the crystallography capabilities at Diamond give us a view of how these processes work.'
Stuart said: 'Studying proteins and the role they play within organisms is like having 100 locks and keys in front of you and not having any idea as to what fits what.
'By solving the structure of these proteins, we understand more about their function and matching them becomes much easier.'
Zhou said: 'It's not just the farming community which stands to benefit from this work.
'These new insights will be fed into the development and refinement of biosensors where detection sensitivity is paramount in areas such as blood tests.
'One of our spin-off companies are also investigating how bees can detect some small quantities of explosives and stand to benefit from any knowledge we generate.'
