Activity of the botanical aphicides 1,5-diphenyl-1-pentanone and 1,5-diphenyl-2-penten-1-one on two species of Aphididnae.

1,5-Diphenyl-1-pentanone (A) and 1,5-diphenyl-2-penten-1-one (B) are natural products extracted for the first time from Stellera chamaejasme. Laboratory bioassay showed that the two products have strong contact activity and very good anti-feedant activity against Aphis gossypii and Schizaphis graminum. Both products showed dose-dependent relationships for both forms of activity against the two aphids, the contact activity of B being about twice that of A. Both products were inferior to methomyl in contact activity but superior in anti-feedant activity against the two aphids. This is the first report of aphicidal activity in these two compounds, which may represent a new class of aphicide.