Insecticidal, repellent, and oviposition deterrent effects of ethanolic extracts of tobacco, tabacum and catnip on greenhouse whitefly

Trialeurodes vaporarium (Westwood), greenhouse whitefly is an important pest of several crops in the world. Presently the application of common pesticides is unavoidable to suppress during a farm season Due to the side effects of chemical pesticides, more research is needed to find low–risk alternatives. In this study, insecticidal, repellent, and oviposition deterrent effects of tobacco, tabacum and catnip ethanolic extracts were investigated on greenhouse whitefly. For this purpose, three concentrations of each plant extract (1000, 2000 and 5000 ppm concentrations) were applied on the whitefly adults based on a factorial complete randomized design with four replications. The pest mortality was recorded at 12, 24 and 48 h of exposure. The results showed that the LC50 values for tabacum, tobacco, and catnip extracts on the pest were determined as 10704, 11996 and 13989 ppm, respectively. The tabacum extract at 5000 ppm imposed the highest mortality rate (95 %) after 48 h and the catnip extract had the lowest effect (28.24%) at 1000 ppm after 12 h, respectively. The oviposition inhibitory effect of the extracts was decremented over time so that egg laying slowly increased afterwards. According to the results, tobacco and catnip extracts with 90 and 22.42% effects had the highest and the lowest repellency property, respectively. Findings are promising in development of safe botanicals; however, it would require confirmation of their positive field results.