Structure/activity studies on aphid alarm pheromone derivatives and their field use against transmission of barley yellow dwarf virus.

Derivatives produced by 1,4‐cycloaddition reactions between acetylenecarboxylic acid esters and the aphid alarm pheromone, (E)‐β‐farnesene, and analogues in which other features of the pheromone molecule were modified, were tested for activity against aphid colonisation. The most active compound, formed from (E)‐β‐farnesene and diundecyl acetylenedicarboxylate, decreased aphid‐transmitted barley yellow dwarf virus infection of autumn‐sown barley.