SYNERGISTIC BIO-PESTICIDE COMBINATION OF PYRETHRINS AND ROTENOIDS FOR THE CONTROL OF THE COCKROACH AMERICANA PERIPLANETA

Pyrethrins and Rotenoids extracts from Chrysanthemum cinerariaefolium and Tephrosia vogelii plants respectively were combined at various ratio mixtures and tested against adult cockroach Americana periplaneta for their efficacy. A mortality rate of 86% in 200 minutes with a synergistic ratio mixture of 28.5:1 w/w was established. The mixture was found to have an observed LC50 of 0.23mg/g and a theoretical LC50 of 0.92mg/g calculated from the individual Pyrethrins and Rotenoids extracts. The synergism expressed as co-toxicity coefficient CC, was found to be 4. The photodegradation of Rotenoids in the combination was found to have a half life of t1/2 of 6.1hrs compared to that of Rotenone and Pyrethrins of 3hrs respectively.