Efficacy of synergized and non-synergized Tagetes minuta methanol extract in controlling Periplaneta americana within households

In this study, comparative analysis of Sesamum indicum L. oil synergized and non-synergized methanol extract of the T. minuta were assayed against P. americana collected from households within Maseno Division, Kenya. The mortality and LC₅₀ for both synergized and non-synergized extracts were determined. The synergized extract had cockroach mortality of 60 (n = 60) (100%) while non-synergized showed mortality of 52 (n = 60) (86.1 ± 1.2%) at 22 μg/ml after 36 h using contact toxicity method. On the other hand, with fumigation method, 100% mortality of the pest was achieved within 30 h using synergized extract while the non-synergized extract afforded 84.0 ± 1.1% mortality at the same concentration after the same period of time. The LC₅₀ for the synergized extract was observed to be 6.31 μg/ml while the non-synergized was found to be 8.91 μg/ml. Thus, T. minuta extract may be used alone or synergized with S. indicum oil for effective management of cockroaches within households.