Semiochemicals

Semiochemicals are signalling chemicals which carry information between living organisms and cause specific responses. When the chemical signal is between individuals of the same species these are known as pheromones. Semiochemicals sent between different species are allelochemicals. Insects are attracted to each other but also to host plants by detecting particular semiochemicals or mixtures of them. Semiochemicals which are therefore a potential target for development of high specificity ‘green’ bio protection products. Of most current interest are semiochemicals that repel pests and/or attract their natural enemies, to keep pest populations below damaging levels.

Semiochemicals can be used in a push-pull strategy for insect control, involving baited traps, attractive border trap crops and repellent sprays. Mating disruption using synthetic insect female sex hormones has been successfully used to control pests in commercial fruit, vegetable and cotton crops for over a decade. Anti-aggregation pheromones also prevent mating populations accumulating in one area and have been used in commercial tree stands.

Already used in pollen beetle monitoring traps for oilseed rape, semiochemicals based interventions would ideally be deployed in slow-release formulation sprays. Highly targeted and environmentally safe, these would require fewer inputs and can involve multiple elements, therefore reducing the likelihood of resistance developing compared with use of conventional chemistry. There is scope to develop crop cultivars with low levels of semiochemicals to enhance pest resistance.

https://link.springer.com/article/10.1007/s11829-017-9569-6

https://repository.rothamsted.ac.uk/download/309b974284b01b955ac47d2aa1d6f1c503c91125bb48a900f79258343c5f1eeb/4558638/10.1007_s11829-017-9569-6.pdf

http://www.oecos.co.uk/pheromone/