Economical novel formulation and evaluation of herbal oils for mosquito and house fly repellent activities
Aromatic plants contain compounds that they use in preventing attack from phytophagous insects with the multiple mechanisms like repellents, feeding deterrents, toxins, and growth regulators etc. Looking at that the present study was carried out with the aim of mosquito and house fly repellent activities with the novel herbal oil formulations. The oils of patchouli, eucalyptus, rosemary, citronella and neem leaves were extracted by hydro distillation method using Clevenger apparatus and various formulations were prepared, viz. tincture, candle and crystal cake. Tincture was evaluated by sprayed in known mosquito larvae and observed for death rate using acetone as control; candle was evaluated on flammability, burning time as well as mosquito and insect repellency test. Furthermore crystal cake formulation was evaluated on appearance, volatility time, stability of fragrance, mosquito and insect repellency test. All the formulations showed remarkable significant dual activities against mosquito and insect population. Based on these preliminary actions, all these formulations were tested in Varthur locality (30 houses and 20 chicken shops) for one month where mosquito and insect populations were more and resulted significant elimination of both the populations. This result may be due to the presence of the active constituents like volatile alcohol, ketone and other constituents in the oils. The result revealed the formulated tincture spray and candle were more effective than crystal cake in relation to killing mosquitoes, insects, stability of fragrance, etc.