The functional significance of E-b-Farnesene: Does it influence the populations of aphid natural enemies in the fields?

Aphids cause much damage to Chinese cabbage in northern China. Over reliance on pesticides have large
environmental and human health costs that compel researchers to seek alternative management tactics
for aphid control. The component of aphid alarm pheromone, E-b-Farnesene (EbF), extracted from Matricaria
chamomilla L., which attracts natural enemies in the laboratory, may have significant implications
for the design of cabbage aphid control strategies. The purpose of this paper is to understand the effects of
EbF on natural enemies to cabbage aphid control in Chinese cabbage fields. Ladybeetles on Chinese cabbage
leaves in EbF released plots and Aphidiidae in EbF released yellow traps were significantly higher
than those of in controls. No significant differences were detected in the interactions of different treatments
and the two years for all natural enemies. More important, lower aphid densities were found in
EbF released plots. Our results suggested that the EbF extracted from M. chamomilla L. could attract natural
enemies to reduce cabbage aphids in the Chinese cabbage fields.