Al Abassi and colleagues* have shown that the Seven-Spot lady beetle has receptors on the antennae that are responsive to biologically significant concentrations of aphid alarm pheromone. When given a choice between an airstream containing aphid alarm pheromone and no odor, the beetles follow the aphid alarm pheromone two thirds of the time. Alarm pheromones may be useful signals for lady beetles to find aphids in a complex environment.
*Al Abassi S, Birkett MA, Petterson J, Pickett JA, Wadhams LJ, Woodcock CM (2000) Response of the seven-spot ladybird to an alarm pheromone and an alarm pheromone inhibitor is mediated by paired olfactory cells. J Chem Ecol 26:1765–1771