A Novel Plant-based Synergist for Pyrethrum and Pyrethroids against Urban Public Health Pests
  Key Words  
  dill seed oil, cockroach, house fly, permethrin, Anopheles stephensi
  Nigel Hill
  Natural pyrethrum and its synthetic analogues are among the most widely used insecticides in medical, veterinary and agricultural use. Low application rates, rapid knock-down and kill, range of duration of activity and good mammalian safety profile make them an active of choice in most domestic applications. The threat to continued use of these compounds is that of resistance in target organisms. To overcome resistance it is common to add a synergist, such as piperonyl butoxide. In this study we report the potential synergistic effects of a botanical substance derived from dill seed oil (Anethum sowa), which has been proven to enhance the biocidal activity of pyrethrins and overcome kdr-type resistance in malaria vector mosquitoes. With an optimal ratio of 1:3.6 pyrethrum to dill seed oil, and an enhanced biocidal activity against medically important urban pest species including Periplaneta americana (L.), Musca domestica (L.) and a pyrethroid-resistant strain of the Asian urban malaria vector Anopheles stephensi (Liston), we consider this combination may be suitable in a wide range of pest control situations.